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DOE Award: DE-FC26-00NT40991

Reporting Period Start Date: December 31, 2002

Reporting Period End Date: March 31, 2004

Report Issued: March 25, 2004

Principal Authors:

Eric Lee Dick Bourne Mark Berman

Submitting Organizations:

Davis Energy Group 123 C St.

Davis, California

Des Champs Technologies Incorporated 45 Natural Bridge School Rd.

Natural Bridge Station, Virginia

TIAX, Incorporated Acorn Park

Cambridge, Massachusetts

Lawrence Berkeley National Laboratory 1 Cyclotron Road

Berkeley, California

Development of a Hydronic

Rooftop Unit – HyPak

Final Report

DAVIS ENERGY GROUP, INC.

Disclaimer:

This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof.

March 25, 2004 DE-FC26-00NT40991 – HyPak – Final Report i

TABLE OF CONTENTS

Table of Contents ............................................................................................................. i Figures .......................................................................................................................... iii Tables ........................................................................................................................... iv References....................................................................................................................... v Bibliography ................................................................................................................... v Acronyms & Abbreviations............................................................................................. vi

1. EXECUTIVE SUMMARY ....................................................................................... 1-1 2. INTRODUCTION .................................................................................................... 2-1 2.1. Background ........................................................................................................ 2-1 2.1.1. The Problem................................................................................................ 2-1 2.1.2. The HyPak Project....................................................................................... 2-1 2.1.3. Phase 1 Work .............................................................................................. 2-2 2.1.4. Phase 2 Work .............................................................................................. 2-2 2.1.5. Phase 3 Goals .............................................................................................. 2-3 2.2. Phase 3 Accomplishments .................................................................................. 2-3 2.3. HyPak Design Concept....................................................................................... 2-4 2.4. HyPak Design Features ...................................................................................... 2-5 3. METHODOLOGY ................................................................................................... 3-1 3.1. Development of HyPak Prototype Design.......................................................... 3-1 3.1.1. Phase 1 HyPak Design................................................................................. 3-1 3.1.2. Phase 2 Design Changes ............................................................................. 3-3 3.1.2.1. Design Changes at Start of Phase 2 ..................................................... 3-3 3.1.2.2. Design Changes Made After Initial Phase 2 Testing............................ 3-6 3.1.2.3. Photos of Phase 2 Prototype...............................................................3-10 3.1.3. Phase 3 Design Changes.............................................................................3-14 3.1.3.1. Design Changes made at start of Phase 3 ...........................................3-14 3.1.3.2. Design Changes made during Phase 3................................................3-19 3.2. Prototype Fabrication .......................................................................................3-20 3.2.1. Laboratory Test Unit ..................................................................................3-20 3.2.2. Photos of Phase 3 Prototype .......................................................................3-20 3.2.3. Field Test Unit ...........................................................................................3-24 3.3. Laboratory Testing ...........................................................................................3-28 3.3.1. Laboratory Test Plan ..................................................................................3-28 3.3.2. Test Conditions ..........................................................................................3-28 3.3.3. Laboratory Test Setup ................................................................................3-29 3.3.3.1. Outdoor Air Loop..............................................................................3-31 3.3.3.2. Indoor Air Loop ................................................................................3-32 3.3.3.3. Instrumentation .................................................................................3-33 3.3.4. Laboratory Test Results..............................................................................3-36 3.4. Field Testing ......................................................................................................3-36 3.4.1. Field Test Plan ...........................................................................................3-37 3.4.2. Field Test Setup .........................................................................................3-37 3.4.3. Field Test Results.......................................................................................3-39

March 25, 2004 DE-FC26-00NT40991 – HyPak – Final Report ii

4. RESULTS AND DISCUSSION ................................................................................ 4-1 4.1. Test Results......................................................................................................... 4-1 4.1.1 Laboratory Test Results................................................................................ 4-1 4.1.1.1. Summary............................................................................................ 4-1 4.1.2.2. Discussion.......................................................................................... 4-3 4.1.2 Field Test Results......................................................................................... 4-7 4.1.3 Product Maintenance.................................................................................... 4-9 4.1.4 Product Reliability ......................................................................................4-10 4.2. Assessment of Commercial Viability and Market Potential ............................4-10 4.2.1 Customer Analysis ......................................................................................4-10 4.2.2 Focus Group Responses ..............................................................................4-11 4.2.3 Concerns.....................................................................................................4-11 4.2.4 Reaction and Conclusions ...........................................................................4-12 4.2.5 Competing Companies ................................................................................4-13 4.2.6 Competing Products ....................................................................................4-14 4.2.7 Market Share...............................................................................................4-17 4.2.8 Market Size.................................................................................................4-18 4.3. Steps Necessary to Develop Technology into a Marketable Product ...............4-19 4.3.1 Technical Hurdles .......................................................................................4-19 4.3.2 Performance Verification ............................................................................4-19 4.3.3 Future Recommended R&D ........................................................................4-20 5. CONCLUSIONS AND RECOMMENDATIONS.................................................... 5-1

APPENDICES

Appendix A – Phase 1 Component Selection...............................................................A-1 Appendix F – Laboratory Test Plan............................................................................. F-1 Appendix G – Laboratory Test Results........................................................................G-1 Appendix H – Field Test Plan .....................................................................................H-1 Appendix I – Field Test Results ................................................................................... I-1 Appendix J – LBNL Laboratory Testing Validation Memo .......................................... J-1

Note: Some appendices were redacted due to confidential business information content.

March 25, 2004 DE-FC26-00NT40991 – HyPak – Final Report iii

FIGURES

Figure 2-1: Hydronic and Refrigerant Schematic......................................................... 2-4 Figure 3-1: Phase 1 CEWC Design ............................................................................. 3-1 Figure 3-2: Phase 1 Configuration............................................................................... 3-2 Figure 3-3: Original Phase 1 Hydronic Schematic ....................................................... 3-3 Figure 3-4: CEWC Design used in Phase 2.................................................................. 3-5 Figure 3-5: Rendering of Phase 2 Prototype (Front)..................................................... 3-9 Figure 3-6: Rendering of Phase 2 Prototype (Rear)...................................................... 3-9 Figure 3-7: Phase 2 Prototype ....................................................................................3-10 Figure 3-8: HyPak Prototype on Test Stand…………………………………………...3-11 Figure 3-9: HyPak Prototype with Cover Panels Removed .........................................3-11 Figure 3-10: Return Plenum with Duct Blaster and High Efficiency Filter ..................3-12 Figure 3-11: Supply Plenum with Plug Fan ................................................................3-12 Figure 3-12: Heating Coil and Condensate Drain........................................................3-12 Figure 3-13: Filter Media ...........................................................................................3-13 Figure 3-14: Controls Enclosure.................................................................................3-13 Figure 3-15: Tower Fan .............................................................................................3-13 Figure 3-16: Heating Water Loop and Equipment.......................................................3-13 Figure 3-17: Original Water Distribution System .......................................................3-14 Figure 3-18: Refrigeration Components .....................................................................3-14 Figure 3-19: Spray Nozzles ........................................................................................3-14 Figure 3-20: Phase 3 Prototype...................................................................................3-18 Figure 3-21: Final Assembly ......................................................................................3-21 Figure 3-22: Controls Enclosures ...............................................................................3-21 Figure 3-23: Equipment Compartment .......................................................................3-22 Figure 3-24: Heating and Cooling Aircoils, Condensate Drain Pan, and Sensors.........3-22 Figure 3-25: Open Condenser, Spray Nozzles, Drift Eliminator, and Tower Fan.........3-22 Figure 3-26: Paper CEWC .........................................................................................3-23 Figure 3-27: Top of Paper CEWC ..............................................................................3-23 Figure 3-28: CEWC and VA Damper .........................................................................3-23 Figure 3-29: Paper CEWC and Sump in Operation.....................................................3-23 Figure 3-30: Field Test Unit – View 1 ........................................................................3-26 Figure 3-31: Field Test Unit – View 2 ........................................................................3-27 Figure 3-32: Plastic CEWC........................................................................................3-27 Figure 3-33: Laboratory Test Setup Schematic ...........................................................3-30 Figure 3-34: HyPak Unit in Laboratory Test...............................................................3-31 Figure 3-35: Outdoor Air Loop ..................................................................................3-32 Figure 3-36: Flow Nozzle with RTD and Static Pressure Probe ..................................3-32 Figure 3-37: Laboratory Instrumentation ....................................................................3-33 Figure 3-38: APT System and Data Taker ..................................................................3-35 Figure 3-39: Data used to Correlate Pressure to VA Flow Rate...................................3-39 Figure 4-1: Top HVAC Market Competitors by 2002 Market Share ...........................4-14 Figure 4-2: HyPak Cost Comparison ..........................................................................4-16 Figure 4-3: HyPak EER Comparison..........................................................................4-16 Figure 4-4: Energy Efficiency Ratings........................................................................4-17

March 25, 2004 DE-FC26-00NT40991 – HyPak – Final Report iv

TABLES

Table 2-1: Phase 3 Performance Goals ........................................................................ 2-3 Table 3-1: Laboratory Test Conditions .......................................................................3-29 Table 3-2: Data Taker Instrumentation .......................................................................3-34 Table 3-3: Pressure Measurements .............................................................................3-36 Table 3-4: Monitored Field Test Sensors ....................................................................3-38 Table 4-1: Laboratory Test Cooling Results ................................................................ 4-2 Table 4-2: Summary of Representative Cooling Test Runs .......................................... 4-5 Table 4-3: Heating Test Results .................................................................................. 4-6 Table 4-4: Uncertainty Analysis .................................................................................. 4-7 Table 4-5: Field Test Data........................................................................................... 4-8 Table 4-6: Focus Group Attendees .............................................................................4-11 Table 4-7: Largest HVAC Companies ........................................................................4-14 Table 4-8: Benefit/Cost (BCR) Comparison ...............................................................4-15 Table 4-9: Comparative Efficiency Levels..................................................................4-17 Table 4-10: West/US Number of Commercial Buildings and Floorspace ....................4-18

March 25, 2004 DE-FC26-00NT40991 – HyPak – Final Report v

REFERENCES

1. NETL 2000 Solicitation .......................................................................................... 1-1 2. NETL 2000 Solicitation .......................................................................................... 1-1 3. E-Source Technical Update, January, 1993............................................................ 2-1 4. Commercial Building Survey Report, September, 1997, PG&E............................... 2-1 5. NETL 2000 Solicitation .......................................................................................... 2-1 6. HVAC&R Research for the 21st Century, July 1997, ARI................................ ........ 2-1

7. Source: Deutsche Bank Securities, Inc…………………….……………………….4-15 8. Nadel, Steven, 1988, American Council for an Energy-Efficient Economy ...........4-16 9. Calculation............................................................................................................4-19 10. Hoovers Online, Aaon .........................................................................................4-20 11. Lexis NexusTM.....................................................................................................4-20 12. Lexis NexusTM.....................................................................................................4-20

BIBLIOGRAPHY

Fisk W.J., Faulkner D., Seppanen O., Palonen J. “Performance and Cost of Air Filtration”. Submitted to Indoor Air, 2001 ............................................... 3-26

March 25, 2004 DE-FC26-00NT40991 – HyPak – Final Report vi

ACRONYMS & ABBREVIATIONS (Alphabetical)

• APT Automated Performance Testing • ARI Air Conditioning and Refrigeration Institute • ASHRAE American Society of Heating Refrigeration and Air-Conditioning Engineers, Inc. • BTU British thermal units • BTUH British thermal units per hour • CAP Commercialization Assistance Program • CEWC Counterflow evaporative water cooler • CFM Cubic feet per minute • DB Dry bulb temperature • DDC Direct digital controller • DEG Davis Energy Group, Inc. • DHC Dust holding capacity • DCT Des Champs Technologies, Inc. • DOE Department of Energy • DOE2 Department of Energy Hourly Simulation Program • DX Direct expansion • EA Exhaust air • ECM Electronically-commutated motor • EER Energy efficiency rating • FPM Feet per minute • GPM Gallons per minute • GWH Gas water heater • HP Horsepower • HR Hour • HVAC Heating, ventilation, & air-conditioning • HX Heat exchanger • HYPAK Hydronic Rooftop Packaged Unit • IAQ Indoor air quality • IN Inch • kW Kilowatts • L/s Liters per second • lb/s Pounds per second • LBNL Lawrence Berkeley National Laboratory • LBNL/IED Lawrence Berkeley National Laboratory/Indoor Environmental Dept. • MERV Minimum efficiency reporting value • MOP Maximum operating pressure • µM Micro meter • NETL National Energy Technology Laboratory • OA Outdoor air • NYB New York Blower

March 25, 2004 DE-FC26-00NT40991 – HyPak – Final Report vii

• Pa Pascals • PG&E Pacific Gas & Electric Company • PVC Polyvinyl chloride • RA Return air • R&D Research and development • RH Relative humidity • RPM Rotations per minute • RTD Resistance temperature device • RTU Conventional roof-top cooling/heating unit • SA Supply air • SCFM Standard cubic feet per minute • SMUD Sacramento Municipal Utility District • SPARK Simulation Problem Analysis and Research Kernel • STARS Single Thickness Airfoil Reduced Sound • TEWI Total equivalent warming impact • TIAX Formerly, Arthur D. Little, Inc. • TXV Thermostatic expansion valve • UV Ultra violet • V Valve • VA Ventilation air • VAC Volts alternating current • VFD Variable frequency drive • W Watts • WB Wet bulb temperature • WC Water column • Wg Water gauge

March 25, 2004 DE-FC26-00NT40991 – HyPak – Final Report Page 1-1

1. Executive Summary

Project Background The majority of US commercial floor space is cooled by rooftop HVAC units (RTU’s). RTU popularity derives chiefly from their low initial cost and relative ease of service access without disturbing building occupants. Unfortunately, current RTU’s are inherently inefficient due to a combination of characteristics that unnecessarily increase cooling loads and energy use. Existing RTU’s in the U.S. consume an estimated 2.4 quads annually.1 Inefficient RTU’s create an estimated 3.5% of U.S. CO2

2 emissions, thus contributing significantly to global warming. Also, RTU’s often fail to maintain adequate ventilation air and air filtration. This project was developed to evaluate the feasibility of a radically new “HyPak” RTU design that significantly and cost-effectively increases RTU performance and delivered air quality.

Project Objective The objective of the HyPak Project was to design, develop and test a hydronic RTU that provides a quantum improvement over conventional RTU performance. Our proposal targeted 60% and 50% reduction in electrical energy use by the HyPak RTU for dry and humid climates, respectively, when compared with a conventional unit.

HyPak Concept The proprietary HyPak concept uses many innovative features including evaporative condensing, ventilation air pre-cooling, high-efficiency heating, heat recovery, and efficient filtration. HyPak’s name derives from the hydronic cooling of the condenser and is short for “Hydronic Packaged Unit”. Volume 2 of this report describes methodologies (Final Report Section 3) and provides the report appendices that contain proprietary HyPak descriptive information.

Project Team The HyPak team includes four organizations:

• Davis Energy Group (DEG), overall management and design • Des Champs Technologies, Inc. (DCT, formerly Des Champs Laboratories, Inc.),

manufacturing and design assistance • Lawrence Berkeley National Laboratory (LBNL), computer modeling and indoor air

quality design • TIAX, Inc. (formerly Arthur D. Little), refrigeration design assistance, cost modeling and

focus group management


Phase 1 Accomplishments In Phase 1 of the project, we:

1. Developed and tested HyPak’s proposed counterflow evaporative water cooler (CEWC) 2. Completed conceptual designs and a physical mockup for a “10 ton equivalent” HyPak 3. Developed a HyPak computer performance simulation 4. Developed a detailed HyPak cost model and evaluated expected HyPak economics 5. Prepared and presented a topical report on Phase 1 activities and HyPak potential

Phase 2 Accomplishments In Phase 2 of the project we:

1. Designed a working prototype 2. Fabricated a working prototype based upon the drawings completed in Task 1 3. Tested, refined and retested the prototype 4. Conducted two focus groups in Sacramento and one in Las Vegas to gather stakeholder

input 5. Evaluated performance results and stakeholder input and prepared and presented a topical

report on Phase 2 activities and results

Phase 3 Tasks and Accomplishments The four Phase 3 tasks were structured to result in design, fabrication, laboratory testing and field testing of a HyPak prototype. The objective was to demonstrate that HyPak could work and achieve its targeted capacity and efficiency goal, under both controlled conditions in a laboratory setting and real-world conditions in the field. Results and accomplishments by task are summarized below:

Task 1: Refine HyPak Design The team began Phase 3 in January 2003 following approval of the statement of work. All subsystems were evaluated and refined. After the team generated a list of specified components, DCT developed a complete set of production drawings using the SolidWorks three dimensional modeling program. They then circulated drawings to all team members for input and review. The team agreed upon several changes and DCT then created production drawings of each sheet metal part in the cabinet. The SolidWorks model took slightly longer than conventional two dimensional drawings, but ensured that all components fit the first time. Changes made to the model automatically update the drawings, saving considerable time. DCT and DEG also developed a controls specification for the HyPak controller.

March 25, 2004 DE-FC26-00NT40991 – HyPak – Final Report Page 1-3 Task 2: Fabricate and Test the Refined HyPak Prototype DCT ordered all components. They used the SolidWorks drawings to program laser cutters and automated press breaks to fabricate all sheet metal components. The components were then welded and fastened together to make the cabinet. DCT installed the components, electrical wiring, and refrigeration and water plumbing lines. They also programmed the digital controller. The prototype was completed in July 2003. DEG, with significant input from LBNL, developed a detailed test plan, including objectives, tests conditions, parameters to be measured, instrumentation, and uncertainty analyses. As in Phase 2, initial test results were below expectations, with initial EER ratings of approximately 10, versus targets of up to18. Fewer changes were made than in Phase 2 when the prototype underwent a dramatic revision. The changes in Phase 3 improved both reliability and performance. Capacities and EER’s remained slightly below expectations for reasons that we better understood after reviewing final data.

Task 3: Install and Field Test the Refined HyPak Prototype With additional financial support from the Sacramento Municipal Utility District (SMUD), we were able to build a second prototype for the field testing. The original statement of work called for a single unit to be used for both laboratory testing and subsequent field testing. Without a second prototype, it would have been impossible to complete Phase 3 on schedule. Even with a second prototype, Phase 3 was completed with a three month extension from NETL. With the exception of a few minor changes, the field test unit is identical to the laboratory unit. The unit arrived at the field test site in November 2003. The field HyPak unit was included as part of a large retrofit from a central system to 10 individual RTUs, and several delays by the installer meant that the field test unit was not started up on-site until January. After a few initial tests, we collected cooling data during a particularly warm spell in March. In addition to performance testing under real world conditions, the field test gave us feedback from HVAC engineers and installers that would not have been possible otherwise. The field test unit will continue to serve a hotel ballroom and should provide data on maintenance and reliability. This experience will influence the design of production HyPak units.

Task 4: Final Report The HyPak team has prepared this Final Report to summarize project activities and report HyPak results and future potential.

Phase 3 Test Results This report summarizes laboratory test procedures and results, including the eight final cooling tests and one final heating test. Cooling results were compromised by modifications that were required to prevent water droplets from entering the ventilation air stream. To deal with this issue, we removed the ventilation air blower and modified the evaporative heat exchanger (CEWC) to fully separate the indirect pre-cooling passages from sump water. This modification reduced the ventilation air flow area by two-thirds and also reduced air flow for condenser

March 25, 2004 DE-FC26-00NT40991 – HyPak – Final Report Page 1-4 cooling in the “no ventilation” mode used for the standard ARI test. Nevertheless, the unit performed at 14.7 EER in the standard test- 33% above the best RTU’s now available. The results of the other two most significant tests are summarized below:

Test Condition Parameter Units Modified ARI Western Max Outdoor Air DB °F 95.5 106.1 WB °F 74.7 66.1 Supply Air CFM 2991 2993 Ventilation Air CFM 363 744 DB °F 79.9 80.7 Sump Water °F 78.5 78.7 Evaporating Temp °F 52 52 Condensing Temp °F 102 102 Cooling Capacity Btu/hr 81,000 85,900 EER Btu/hr/W 14.7 17.3

The modified ARI test represents a typical hot day in many eastern U.S. climates, while the “western max” test represents a hot day in the western U.S., with relatively higher dry bulb and lower wet bulb temperatures. The tests were run with ventilation air rates of approximately 12% and 25% of the supply air rate respectively. Many other parameters, including the supply air CFM and condensing and evaporating temperatures, vary little between the two tests. But the parameters that did vary are significant. Despite the hotter outdoor air, the western max test shows nearly identical sump water temperature, higher capacity, and higher EER. Also, due to the lower outdoor wet bulb temperature, the ventilation air was pre-cooled by more than 25°F, compared to about 15°F in the modified ARI test. These results indicate the value of the evaporative process that responds to the outdoor wet bulb temperature. At the “western max” condition the prototype HyPak did not match the capacity of a conventional 10-ton RTU, which would be 8 to 8.5 tons. Notably though, HyPak capacity increased from 6.7 tons at ARI Standard Rating Conditions to 7.1 tons at the western max condition. Phase 2 tests showed that the higher the ventilation air flow rate, the higher the HyPak capacity and EER. In comparison, the conventional RTU’s capacity and EER both fall with increasing ventilation air rate and outdoor temperature. (See Section 4.1.1.2 for detailed discussion). The test results made clear that several Phase 3 modifications caused reduced performance. Based on the results, we defined a third prototype HyPak design that would resolve remaining issues. This improved design is expected to achieve the 18 EER target for western conditions with 25 to 30% ventilation air. The new design also provides a full open economizer cycle that is superior to that used on any current RTU equipment.

Market Viability and Steps to Commercialization Selection and purchase decisions for RTU’s are made with input from a variety of participants, including HVAC contractors, facility managers and design engineers. Although building landlords and tenants are the ultimate buyers, frequently the recommendations of their

March 25, 2004 DE-FC26-00NT40991 – HyPak – Final Report Page 1-5 professional staff or contractors form the defacto purchase decisions. To learn how members of these groups would respond to HyPak, we scheduled three focus groups in September, 2002. Two were held in Sacramento, California and one was held in Las Vegas, Nevada. There were 27 participants, including contractors, developers, owners, HVAC engineers, manufacturers’ representatives and facility managers. The general consensus was that if the energy savings promised by HyPak could be achieved, the product would likely succeed. However, the participants stressed that a number of units must be demonstrated in the field to show what “real” savings are in a given climate. The focus group participants also voiced two primary areas of concern. These were initial cost and maintenance. One utility representative attended and volunteered that the peak savings for HyPak would make it eligible for many utility incentive programs. This would ameliorate the higher first cost. The participants indicated that maintenance concerns could be alleviated if the manufacturer offered:

• Maintenance support contracts • Installation and maintenance training • Local support • Off the shelf, in-stock parts • Good, clear documentation.

In sum, the overall reaction to HyPak was positive. There was general agreement that the HyPak concept fills a real need for an energy efficient rooftop air conditioner with a well thought-out, novel design. Participants in California seemed most concerned about high energy costs and were most receptive to the HyPak concept. The RTU Market An evaluation of HVAC manufacturers shows that four companies have approximately one-third of the market. These are Carrier (United Technologies), Lennox International, Trane (American Standard) and York International. The next tier of manufacturers is small relative to the total market, with typical company-wide sales of $100 to $200 million dollars. The RTUs currently offered are nearly all aircooled, of similar design, and have few differentiating features. Energy efficiency ratings typically range between 10 and 11. The RTU market is large. In a 1998 report, the American Council for an Energy Efficient Economy (ACEEE) found that RTUs were used in over 50% of US commercial buildings because of their low first cost, simple design, and roof mount capability. They were described in the report as “a commodity item, often costing less that $500 per ton, resulting in many compromises including small coils, constricted air paths, low efficiency compressors and fans, and leaky ductwork. “ The HyPak design overcomes these shortcomings and has an EER that is nearly double the rating of current high efficiency products. HyPak’s initial cost will be higher, but once volume production is achieved, paybacks of approximately two years should be attainable. DEG believes that HyPak can capture 20% of the RTU market within ten years of introduction. A 1995 study by Arthur D. Little, done on behalf of DOE’s Office of Building Technologies, indicates that

March 25, 2004 DE-FC26-00NT40991 – HyPak – Final Report Page 1-6 technologies with a two year payback achieve 7% market share within five years, and an ultimate adoption rate of 30% ten to twenty years after introduction. On this basis, a 20% HyPak market share within ten years appears reasonable. Based on estimates of national market size exceeding $2 Billion dollars (see pages 4-18 and 4-19), the potential market for HyPak is estimated to exceed $400 million dollars in annual sales within ten years of introduction. To achieve this success, a number of challenges must be met. First, the HyPak project prototype design must be reduced to a simpler, reliable design for units in multiple sizes. Tooling must then be procured and production commence. To verify performance, demonstration sites need to be identified in conjunction with utilities throughout the west. Marketing should start in California and then expand to the other western states, with emphasis on the demonstrated results in each region. There is a good likelihood that that Des Champs Technologies will commercialize HyPak. The initial version will likely deliver 100% ventilation air. This “most simple” HyPak will fill a market niche and take full advantage of the benefits of an indirect evaporative heat exchanger as demonstrated in the HyPak project. To take full advantage of the progress made in the project toward perfecting a “mixed air” HyPak version, we recommend further funding to develop an advanced HyPak design whose schematic cross-sectional view is shown in Appendix K, and which is described more fully in Section 4.3.3. With the introduction of a basic HyPak unit and the development of a more advanced “mixed-air” version, HyPak’s full energy savings potential can be achieved.

Conclusions and Recommendations Based on the work completed in this project to develop the HyPak hydronic packaged rooftop unit, we offer the following conclusions:

• There is a significant opportunity to improve the efficiency of widely-used “mid-sized” (10-30 ton) packaged cooling/heating/ventilation units, particularly regarding cooling and ventilation performance, where energy consumption can be cut by more than 50%.

• The major opportunity for improving cooling comes from the application of evaporative cooling to both the condensing function of the refrigeration cycle and to ventilation air. This strategy significantly reduces annual energy consumption, and is even more effective at reducing peak cooling demand.

• Minimizing maintenance costs and demonstrating a substantial reduction in energy costs are essential to success for a new evaporatively-based rooftop unit.

• Based on input received from focus groups conducted in this project, a reliable RTU that offers 50% cooling energy savings will be well received in the marketplace.

• The counterflow evaporative water cooler (CEWC) first reduced to practice in this project is important to the design of an efficient, compact hydronic RTU. This project has demonstrated a CEWC that can cool condenser inlet water to within 5°F of the wet bulb temperature while at the same time pre-cooling 105°F outdoor air to approximately 80°F when the wet bulb temperature is 70°F.

• The two thermoformed plastic CEWC’s prototyped in Phase 3 performed well and warrant additional R&D to refine manufacturing procedures and reduce cost.


• We made considerable progress in all three phases of this project, by proving the potential of the CEWC in Phase 1, designing, building, and testing a first working prototype in Phase 2, and fabricating two redesigned field-worthy units in Phase 3. One of the two was installed at a field test site and is equipped for ongoing monitoring.

• The initial airflow configuration used in both the designs implemented in this project has two liabilities that can be overcome with an improved configuration. The first liability is that a limited volume of ventilation air can be delivered to the occupied space. The second liability is the proximity of reservoir water to the ventilation air stream, generating fears that in some pressure conditions contaminants might be drawn into the ventilation air.

• A revised configuration based on project experience eliminates these liabilities and would provide superior economizer performance. The revised configuration employs two smaller CEWC components that share duties but always maintain separation between the reservoir and ventilation air. The CEWC’s would use revised air and water inlet patterns that facilitate a lower profile and smaller cabinet. Based on project results we project that a next prototype can cost-effectively surpass 18 Btu/watt-hr cooling efficiency in typical Western operating conditions and may approach 20 Btu/watt-hr, a major improvement over the 12 Btu/watt-hr in best available current technology.

Based on these conclusions, we strongly recommend funding support for the following continuing activities:

• Design, fabrication, and lab testing of a third prototype configured as summarized above

and more fully described in Section 4 of this report. • Development of the advanced CEWC design with side air entry/exit paths and low profile

water feed system. • Based on successful completion of the design/development tasks, implementation of a

field test program that places at least three units of the refined design in a range of U.S. climates.


2. Introduction

2.1. Background More than half of all U.S. commercial floor space is cooled by packaged units, most of which are rooftop units (RTU’s).3 Pacific Gas & Electric Company (PG&E) reports that of 3.5 million tons of commercial cooling capacity in its service territory, two-thirds is provided by packaged units.4 There are strong reasons for the popularity of these units. RTU’s are inexpensive, they provide a measure of zonal control, are easy to install, can be serviced without disrupting occupants, and are familiar to contractors, engineers and operators. Central systems with chillers and boilers are generally more efficient than RTU’s, but have been losing market share due to higher first costs and greater complexity.

2.1.1. The Problem Today’s packaged units are inefficient. Their rooftop location exposes them to elevated temperatures that increase ventilation air cooling loads and reduce refrigeration efficiency. Conventional RTU’s have a single speed blower motor that uses the same amount of power whether it’s satisfying part loads or peak loads. “Direct expansion” evaporator coils with uncontrollable surface temperatures often cause unnecessary latent cooling, and thin coils with closely-spaced fins collect dust and bacterial growth and produce downstream moisture in plenums and ducts due to “pull-off” of condensate droplets that bridge the narrow gap between the fins.

Inefficient RTU’s have major consequences. Buildings account for 37% of annual U.S. energy consumption, and energy costs for buildings total approximately $230 billion a year.5 Existing RTU’s consume approximately 2.4 quads annually. Energy consumption for buildings generates 35% of all CO2 emissions; an estimated 10% of this amount is due to RTU’s. This output contributes significantly to global warming. 97% to 99% of the Total Equivalent Warming Impact (TEWI) of air conditioning is due to the release of CO2 as a by-product of power generated to run the equipment.6 Thus, improvements in equipment efficiency can have major impact on overall energy consumption and global warming.

Another problem with rooftop units is that they often fail to maintain adequate indoor air quality. Inadequate ventilation is one cause of poor air quality with RTU’s, which have no system for monitoring the ventilation air rate. Many RTU’s are equipped with economizers to deliver additional outdoor air in favorable conditions, but economizer operation is often faulty due to poor design, lack of maintenance, or insufficient exhaust air. In addition, RTUs typically do not provide adequate filtration of indoor air.

2.1.2. The HyPak Project The overriding objective of the HyPak Project was to design, develop and field test a high-efficiency rooftop unit that provides a quantum improvement over conventional RTU performance. Our proposal targeted 60% and 50% reduction in electrical annual


energy use by the HyPak RTU for dry and humid climates, respectively, when compared with a conventional unit. An additional objective was the development of an evaporative heat exchanger (the Counterflow Evaporative Water Cooler or CEWC) that efficiently cools water and ventilation air. We sought to accomplish these goals while improving indoor air quality. The HyPak team included four organizations:

• Davis Energy Group (DEG), overall management and design • Des Champs Technologies, Inc. (DCT, formerly Des Champs Laboratories, Inc.),

manufacturing and design assistance • Lawrence Berkeley National Laboratory (LBNL), computer modeling and indoor

air quality design • TIAX, Inc. (formerly Arthur D. Little), refrigeration design assistance, cost

modeling and focus group management

2.1.3. Phase 1 Work In Phase 1 we:

• Successfully designed, prototyped and tested a CEWC that meets project objectives

• Designed a preferred HyPak configuration and built a full scale mockup • Developed a detailed hourly simulation model of HyPak performance • Developed a detailed HyPak cost model • Applied the two models to estimate HyPak economics in 9 building/climate

scenarios We met all Phase 1 objectives. Results indicated that HyPak ultimately promises electrical energy savings exceeding 60% in dry climates, with accompanying peak load reductions of approximately 50%. Phase 1 was completed in July 2001.

2.1.4. Phase 2 Work Upon approval of our Phase 1 work and Phase 2 funding, we began work on Phase 2, in which we:

• Held a team design meeting to review all aspects of the HyPak design • Revised the unit configuration and some component selections • Prepared a complete set of prototype drawings • Fabricated a full-scale working prototype • Performed initial tests on the prototype • Refined the design to improve performance • Tested the revised prototype in a variety of operating conditions • Held three focus groups with industry professionals to assess their enthusiasm for

the HyPak concept The prototype met all performance testing objectives. At ARI standard rating conditions, we recorded an EER of 21.4 with a cooling capacity of 8.4 tons. At conditions more


typical of design days in Western locations, the EER reached as high as 21.6 with a capacity up to 8.15 tons. In both cases, we exceeded our targets, as shown in Table 2-1.

2.1.5. Phase 3 Goals The overall goal of Phase 3 was to refine the HyPak design, fabricate a second prototype, test it in the lab, and then test it in the field. Specifically, Phase 3 goals included:

• Incorporation of design improvements to reduce production costs, optimize performance and enhance reliability and maintainability based on the work completed in Phase 2

• Fabrication of a refined HyPak prototype incorporating the design improvements • Development of lab test and field test plans in conjunction with Lawrence

Berkeley National Laboratory • Completion of laboratory performance testing • Monitoring of performance of the prototype in the field, collecting data on air and

water quality, reliability and performance efficiency • Updating the simulation tool developed in Phase 1 • Completion of this final report

2.2. Phase 3 Accomplishments In Phase 3 we:

• Revised the unit configuration and some component selections • Prepared a complete set of drawings of a revised cabinet and assembly • Fabricated two full-scale working prototypes • Performed initial tests on one prototype • Reworked both prototypes to improve performance • Tested one prototype in a variety of operating conditions • Installed and tested the second prototype in the field • Completed this final report

The prototype met nearly all performance testing objectives. At ARI standard rating conditions, we recorded an EER of 16.3 with a cooling capacity of 6.7 tons. At conditions more typical of design days in Western locations, the EER reached as high as 18.2 with a capacity up to 7.5 tons. The Phase 3 targets and laboratory test results are summarized in Table 2-1.

Table 2-1: Phase 3 Performance Goals & Achievements

Standard Rating Conditions 95/75 80/67 76,800 80,300 16.6 16.3Standard Rating Conditions, with VA 95/75 80/67 66,800 81,000 14.4 14.7

Western Summer Conditions 95/66 76/64 79,500 90,300 18.0 18.2Western Maximum Conditions 105/70 80/67 82,600 85,900 18.2 17.3

Proposed HyPak Performance Targets10 ton Prototype Unit

Results from HyPak SPARK computer modelTotal Cooling

Delivered (Btu/h)

Actual Cooling Delivered (Btu/h)

Outdoor Air DB/WB

Return Air DB/WB

Actual EER

Target EERTest

Operating Conditions


2.3. HyPak Design Concept The HyPak design concept consists of:

• A specialized cooling tower (the CEWC) that evaporatively cools condenser water and indirectly evaporatively cools ventilation air

• Variable speed supply blower motor with direct drive • Low-refrigerant volume system using a scroll compressor, water-cooled condenser and

an oversized evaporator aircoil • Minimal pressure drop components • Hydronic heat delivery combined with a high-efficiency, variable-capacity tankless water

heater. • High efficiency filter combined with capture-and-kill ultra-violet (UV) disinfection

system. Conceptually, HyPak works as shown in Figure 2-1.

Figure 2-1: Hydronic and Refrigerant Schematic


2.4. HyPak Design Features The HyPak design developed in this project has several specific advantages over conventional RTUs that allow it to meet equivalent building cooling loads with reductions in peak electrical energy consumption up to 50%.

• The water-cooled condenser combined with the CEWC effectively de-couples the condensing temperature from the ambient dry bulb temperature and allows the refrigerant system to operate much more efficiently, especially in dry climates.

• Indirect evaporative pre-cooling of the ventilation air reduces compressor load significantly during peak demand hours, allowing for a much smaller compressor. This is particularly effective in applications that require significant amounts of ventilation air.

• A variable speed supply blower motor maximizes efficiency in part-load conditions. • The oversized refrigerant aircoil:

o increases evaporative temperature to increase compressor efficiency, o decreases latent fraction to eliminate unnecessary dehumidification in dry

climates, and o allows for a smaller motor with a lower face velocity without risk of freeze-up.

• Low pressure drop components reduce supply motor size. • Direct drive eliminates losses due to belts and pulleys. • The supply blower motor is mounted on the outside of the cabinet to remove motor heat

from the building air stream. At the same time, HyPak delivers higher indoor air quality with a high efficiency air filter and capture-and-kill UV disinfection system. Furthermore, the CEWC nearly eliminates the energy penalty normally associated with cooling ventilation air, encouraging operators to supply more fresh air to the building. The HyPak design uses off-the-shelf components to accomplish most of these savings. The exception is the Counter-flow Evaporative Water Cooler (CEWC). The CEWC is an innovative heat exchanger that cools water while simultaneously cooling ventilation air. The air paths in the Phase 3 CEWC are shown in Figure 3-4 (see Section 3 – Methodology in Volume 2).


3. Methodology

3.1. Development of HyPak Prototype Design The basic HyPak concept was developed in Phase 1 with particular emphasis on the CEWC. In Phase 2, we drafted a complete set of detailed drawings and produced a working prototype for laboratory testing. Initial test results were disappointing, so we made changes to the prototype to improve performance. Subsequent testing confirmed a significant improvement in capacity and energy efficiency. In Phase 3, we refined the design to reduce cost, address manufacturing and marketing concerns, and improve reliability in anticipation of in-field operation.

3.1.1 Phase 1 HyPak Design Because the CEWC is the only non-standard component in the HyPak design, a significant portion of Phase 1 was devoted to its development. Four narrow-scale prototypes of varying design were built and tested at DEG. We selected the preferred configuration and DEG built a full-scale version that was tested at DCT. The design used for the full-scale CEWC prototype is shown in Figure 3-1.

Figure 3-1: Phase 1 CEWC Design

In Phase 1, we developed a through-the-roof HyPak configuration to minimize pressure drop and cabinet heat gains. In addition, this arrangement would reduce infiltration and leakage, and because most of the unit is below the roof surface, the footprint and volume on the roof would be minimal. This configuration is shown in Figure 3-2.


Water Heater

CEWC Fan

Controls

Filter

Aircoil

Blower Wheel

Blower Motor

CEWC

Condenser

Compressor

Evaporator

Figure 3-2: Phase 1 Configuration

Originally, we developed a hydronic circuit that could circulate sump water directly to the hydronic air coil. When conditions and building loads permit, the system could deliver evaporatively-cooled water to the coil without compressor operation. During normal operation, a 3-way valve split the hydronic system into two separate loops. This arrangement is shown in Figure 3-3.


Figure 3-3: Original Phase 1 Hydronic Schematic

A cost-benefit analysis at the end of Phase 1 determined that it was not worthwhile to include the free-cooling mode. Consequently, we changed to a DX cooling coil with a closed hydronic heating loop. This design offers reduced fouling in the heat exchanger and enables the use of a glycol-water mixture in the closed heating loop to reduce freeze danger. For an explanation of the components selected in Phase 1, see Appendix A.

3.1.2. Phase 2 Design Changes Phase 2 design development took place in two steps. The initial design was fabricated and tested in the first half of 2002. After test results of this design proved disappointing, we made several major design changes to increase capacity and energy efficiency (EER).

3.1.2.1. Design Changes at Start of Phase 2

Above-the-Roof Horizontal Configuration The through-the-roof design submitted in the proposal and developed in Phase 1 has a small supply air pressure drop due to the straight-through flow arrangement. It reduces load due to the elimination of cabinet gains and leakage/infiltration that are inevitable when airstreams move above the roofline in an RTU. Unfortunately, this arrangement complicates maintenance for components below the roofline, such as the filter, bearings, sheaves, belts and condensate pump. Maintenance is an important factor for customers and is critical for a new product


with the sophistication of HyPak. Based on these service issues the team decided to move to a more conventional horizontal configuration. This change facilitated direct drive of the supply blower, eliminating the belts, pulleys and sheaves and the associated motor losses. We also were able to remove the condensate pump from the design and use a conventional gravity drain. In addition, this change makes HyPak compatible with the curbs used for conventional RTU’s, thus opening the large retrofit market to HyPak.

Tower Fan Motor We specified a variable frequency drive (VFD) on the tower fan motor for the prototype to allow evaluations of tower and supply blower interactions.

Exhaust Air Inlet to CEWC In the Task 1.1 CEWC design, building exhaust air (EA) was supplied to the CEWC at the bottom of the dry passages opposite the VA outlet. We decided to lower the sump level and supply the EA just below the CEWC plates to simplify ducting and assembly. A short baffle was incorporated in the corner of each dry passage to minimize EA being recirculated into VA. The revised CEWC layout is shown in Figure 3-4.

Figure 3-4: CEWC Design used in Phase 2

Direct Drive Supply Blower Motor The Phase 1 configuration required that the supply blower have a belt driven motor. The Phase 2 “above-roof “design accommodated a direct drive motor.


Coaxial Water-Cooled Condenser Preventing fouling of the plate-type refrigerant-to-water condenser heat exchanger specified in Phase 1 was a concern of the team. In Phase 2, we specified a coaxial water-cooled condenser heat exchanger. We hoped to use an array of 48” long straight coaxial condensers (a modified version of a standard DCT product), but it was not possible to convert it to this use. Instead, we selected an off-the-shelf spiral-wound coaxial heat exchanger made by Edwards Engineering. This unit is not cleanable, but it is less susceptible to fouling and less expensive than the plate-type heat exchanger.

Capture-and-Kill UV Disinfection The Phase 1 design specified a Nomad UV disinfection system from Bio-Fighter. This system, located in the supply plenum, used UV (ultra-violet) radiation to kill biological contamination in the supply air stream in order to improve indoor air quality. Peng Xu of LBNL, who created the computer model in Phase 1 and has a background in UV disinfection, conveyed that such a system would be impractical for HyPak. To kill biological contaminants, there must be a sufficient combination of UV intensity and residence time; the higher the intensity, the shorter the required residence time, and vice-versa. To achieve the desired level of air purification would have required between 10 and 20 seconds, depending on the particular bulb arrangement. At a velocity of 200 to 400 feet per minute, an additional 10 feet of cabinet space would be required, which clearly is not feasible. In addition, true disinfection would require much higher UV intensity, using about 600 W, or the equivalent of a ¾ hp motor. For these reasons, effective UV air purification is only used in select buildings, such as hospitals. (UV “purifiers” are ineffective in most installations in the residential and commercial markets due to inadequate residence time.) Instead of disinfecting the fast-moving supply air stream, most effective UV systems are directed at a stationary target, meaning that the intensity (and thus first cost and operating costs) can be quite low because the residence time is unlimited. In fact, many systems operate less then one hour per day. The UV system is aimed at a source of biological growth, such as an aircoil, and these systems are very effective at keeping the target clean. The downside is that only surfaces receiving the radiation are kept clean, meaning that deep coils with close fin spacing often have some growth even with a UV system. For most HVAC applications, the aircoil is the best target for a UV system. However, we felt that HyPak will have little or no growth on the aircoil because operation in dry climates with reduced latent cooling will limit condensate on the aircoil. Furthermore, studies have shown that wide fin spacing such as on the HyPak aircoil make it hard for growth to bridge between fins. Instead, we decided to aim the UV system at the upstream side of the air filter. This reflected our concern that HyPak CEWC is a potential source for biological growth. Our strategy was to use the high-efficiency air filter to trap biological contaminants, where the UV system can destroy them before they colonize. This type of strategy is known as “capture-and-kill.”


We also considered placing UV lamps in the sump to stop biological growth in the CEWC. But treating the entire wet and dry passages would require a higher intensity system, and the bulbs would have to be housed in quartz sleeves because of the wet environment. Such systems are also dependant on regular cleanings. The need for such a system would only be known after an extended period of field testing, and as such was not evaluated during this project.

3.1.2.2. Design Changes Made After Initial Phase 2 Testing Upon analyzing the results of the initial Phase 2 testing, we searched for ways to improve HyPak performance. In particular, we sought to increase EER (which was testing in the low teens) by increasing capacity and/or decreasing power consumption. We chose to focus on reducing power consumption, with the hope that we might also increase capacity in the process. We recognized that any significant rework of the prototype would prevent us from completing Phase 2 on schedule, but we felt the initial test results greatly underrepresented the potential performance of the HyPak design. We made the following changes to the Phase 2 prototype:

Cooling Aircoil The originally installed hydronic aircoil was integral to the HyPak design in the project proposal because it allowed three delivery modes via a compact and efficient heat exchanger: evaporatively cooled sump water, compressor chilled closed loop water, and heated water. Once we eliminated the first mode in Phase 1, alternative delivery methods were available to us. With a 6-row refrigerant aircoil, heat is transferred air-to-refrigerant, instead of air-to-water-to-refrigerant. We estimated that eliminating one of the heat exchanges would yield a gain of about 5% in capacity, because the compressor would have a higher evaporating temperature while delivering the same supply air temperature. A higher evaporating temperature increases the capacity and reduces the power consumption of the compressor. This change also reduced cost by removing three components: the refrigerant-to-water heat exchanger, the delivery loop circulator pump, and the motorized 3-way valve. In addition, by eliminating the power consumption of the pump, the change further increased system EER. However, this change did affect the system’s ability to regulate the latent cooling fraction. Based on the relative humidity of the return air, the system of the original design could have cycled the delivery pump to increase the coil temperature and reduce latent cooling. But the large surface area of the 6-row refrigerant coil allows a higher average coil temperature than in the smaller coil of a conventional RTU. We retained the wide 8-fins-per-inch spacing of the hydronic aircoil (versus 15 in a conventional RTU) to minimize pressure drop and opportunities for bacterial growth across the fins.

Heating Aircoil Without the 8-row hydronic aircoil, we needed to find another way to deliver heating. We considered a standard furnace gas-pack, but these have lower efficiencies than the condensing water heater. A gas-pack would also increase air pressure drop and increase overall cabinet size. To avoid this, we chose to use a single row hydronic coil with 9 fins-per-inch for heat delivery and kept the Munchkin condensing water heater. This design change had no impact on the


pressure drop or cabinet size, and the pump on the glycol-water loop was downsized to lower cost and to reduce power consumption.

Condenser Loop Piping One of our major concerns with the test results was low water flow rate in the condenser loop, which reduced condenser and CEWC performance, despite a large (1 hp) submersible pump. To decrease pressure drop, we changed from 1” copper tubing to 1-1/2” PVC pipe, which is also cheaper and reduces assembly time.

Water Spray Nozzles We changed the water distribution system from perforated water feed tubes to self-cleaning spray nozzles to reduce air-side pressure drop in the CEWC dry passages. Spray nozzles are cheaper and easier to assemble than the complicated feed tube system. We also felt they might increase the enthalpy of the CEWC exhaust air because the water is warmer than the air leaving the wet passages. As the saturated air is warmed, it can absorb more moisture, evaporatively cooling the falling water droplets before they reach the wet passages, releasing some of the condenser heat before it is able to heat the CEWC dry passage walls. However, this change added to the height of the CEWC cabinet and resulted in the need for a drift eliminator to protect the motor in the later field test unit.

Condenser Pump The original 3/4 hp submersible condenser pump was first replaced with a larger 1 hp unit in an attempt to increase flow rate. However, both large pumps had a major EER penalty. During the redesign, a 1/6 hp Taco circulator was installed. Circulators are about four times as efficient as available submersible pumps. This alteration reduced power consumption and maintained the same flow rate.

Tower Fan Blade We switched to a blade with higher pitch that delivers more airflow.

Tower Fan Motor The ¾ hp tower fan motor was replaced with a ½ hp unit to reduce system power consumption, but it was not able to deliver the same airflow rate. During most test runs, the flow rate through the tower was boosted by external fans.

Supply Blower Wheel. The ACME wheel originally specified is a value-engineered component for high-volume products. To maximize efficiency, we replaced it with a more efficient and expensive wheel from New York Blower.

Supply Blower Motor The 1 hp tower fan motor was replaced with a ¾ hp unit to reduce system power consumption, but like the tower fan, it also was not able to deliver the same airflow rate. During most test runs, the flow rate through the tower was boosted by external fans.

Refrigerant Settings We reduced the refrigerant superheat from 20 °F to about 5 °F. More superheat protects the compressor, but wastes compressor capacity. Conventional


reciprocating compressors combined with DX coils often need up to 20°F superheat to avoid premature failure. However, the compliant scroll compressor from Copeland is more robust and is designed to be run with 0°F superheat in chiller applications. Even with the DX coil instead of a chiller, we used 0-7°F superheat in the testing. We varied superheat using a microprocessor controlled thermostatic expansion valve (TXV).

Artist renderings of the Phase 2 HyPak (prepared for the Focus Group presentations in Task 2.4) are shown in Figures 3-5 and 3-6.


Figure 3-5: Rendering of Phase 2 Prototype (Front)

Figure 3-6: Rendering of Phase 2 Prototype (Rear)

The components of the revised Phase 2 prototype are shown in Figure 3-7.


Location Component Location Component

A CEWC J Refrigerant (DX) cooling aircoil B Supply blower plug fan wheel K Duct Blaster VA fan C Supply blower motor L High efficiency air filter D Tower fan M Ventilation air damper E Tower fan motor N Exhaust air damper F Condenser loop circulator pump P Hydronic heating coil G Water distribution spray nozzles Q Water heater H Coaxial condenser heat exchanger R Heater loop circulator pump I Compressor S Controls enclosure

Figure 3-7: Phase 2 Prototype

3.1.2.3. Photos of Phase 2 Prototype The completed Phase 2 HyPak prototype is shown in Figures 3-8 to 3-19.


Figure 3-9: HyPak Prototype with Cover Panels Removed

Figure 3-8: HyPak Prototype on Test Stand

March 25, 2004 DE-FC26-00NT40991 – HyPak – Topical Report Page 3-12

Figure 3-12: Heating Coil and Condensate

Drain

Figure 3-10: Return Plenum with Duct Blaster and High Efficiency Filter

Figure 3-11: Supply Plenum with Plug Fan


Figure 3-14: Controls Enclosure

Figure 3-15: Tower Fan

Figure 3-16: Heating Water Loop and Equipment

Figure 3-13: Filter Media


3.1.3. Phase 3 Design Changes The Phase 3 design was an evolution of the Phase 2 design. We were satisfied with the performance of the Phase 2 design, and so focused on evolutionary changes that addressed reliability, maintainability and manufacturability concerns. Two prototypes were built in Phase 3 – one for laboratory testing and one for field testing. Differences between the prototypes were minor.

3.1.3.1. Design Changes made at start of Phase 3

CEWC We needed an additional CEWC for the second prototype. The first CEWC used plates assembled from Munters CelDEK paper laminated to polystyrene film. The plates were separated with spacers made from strips of corrugated plastic. This

Figure 3-18: Refrigeration Components

Figure 3-17: Original Water Distribution System

Figure 3-19: Spray Nozzles


CEWC design required substantial manual labor and custom manufactured materials. For a similar cost, in Phase 3 we produced a second CEWC using custom thermoformed plastic plates. The paper-based CEWC was used for the laboratory test unit due to its higher potential performance (because of the better wetting behavior) and the plastic-based CEWC was used in the field test unit due to its longer expected life. The plastic plate CEWC uses the same configuration as the paper-laminate unit, except that we integrated spacers into the molded plates, and used copper strips to clamp adjacent plates together. The assembly time was reduced by about 90%. In volume production, assembly of the plastic CEWC could be nearly fully automated.

Condenser The helical coaxial condenser used in Phase 2 was damaged from the high operating pressures of R-410A. In addition, it was not cleanable, making it questionable for permanent field operation. For the Phase 3 prototype, we designed an open condenser and located it above the CEWC and below the water spray nozzles. Similar to a conventional aircoil, the open condenser was an all-copper design without fins. We installed four row and three row condensers in the laboratory prototype and field test unit, respectively.

Cabinet We made two major changes to the HyPak cabinet design:

• We cantilevered the sump over the roof so that any leak that might develop in the tower would drip harmlessly onto the roof surface and flow to the roof drains. Unlike most RTUs, where the curb matches the footprint of the cabinet, the HyPak curb only encompasses the area under the supply and return duct connections. HyPak is larger than conventional RTUs, so this design change will also makes retrofits easier by minimizing the difference in curb openings.

• The equipment cabinet, which was located over the supply fan and gave the Phase 2 prototype a “saddle” shape, was moved alongside the CEWC to consolidate the two tall elements into one. This change reduced the amount of sheet metal used in the cabinet, simplified component installation, and reduced the perceived mass of the unit.

The Phase 3 HyPak design was modeled in SolidWorks. This design approach offered more flexibility and precision, and will facilitate the transition to production. The cabinet design included features found in typical DCT products to ease assembly and installation.

Controls The Phase 2 prototype did not require automated controls because it only operated in the laboratory. Because of the field test, the Phase 3 prototype required fully automated controls. DCT selected a Johnson Metasys DX9100 direct digital


controller (DDC) because it is powerful, flexible and easy to program. DEG and DCT developed the control sequence, requiring nine revisions before we were satisfied that the unit would operate correctly. Once installed in the field, the programmer at DCT worked with DEG to fine-tune the controls to real-world application.

Thermostatic Expansion Valve In Phase 2, we used an electronic TXV from Sporlan to manually control the refrigerant flow rate. For the Phase 3 prototypes TIAX selected a conventional 8 ton R-410A TXV with MOP (maximum operating pressure).

Actuated Dampers In the Phase 2 prototype, there was no damper to prevent VA from entering the indoor loop. Even when the Duct Blaster was turned off, about 300 CFM was drawn through it by the supply blower. In Phase 3, we installed a damper at the CEWC outlet and cut the sump air inlet to prevent outdoor air exchanges in non-ventilation operating modes. In production, these dampers will be linked and driven with a common actuator.

Barometric Dampers Two barometric dampers were included in the Phase 3 design. We added a backdraft damper on the tower fan exhaust to prevent backflow through the CEWC when the tower fan is off. Another backdraft damper was added at the RA inlet to prevent backflow when the VA blower is the only fan running. That blower could positively pressure an otherwise normally depressurized plenum and would backfeed air through the return duct.

Tower Fan In Phase 2, the tower fan was only able to move 2200 CFM on its own. During the Phase 2 tests, we often boosted the static pressure in the OA duct to get 3000 CFM of flow through the tower. In Phase 3, we replaced the four blade fan with a higher flow six blade model. The blade required that we increase the motor size from ½ hp to ¾ hp. We retained the variable frequency drive to allow us to evaluate different tower fan speeds, but it was still our hope that the production HyPak would not require it.

Supply Blower In Phase 2, the supply blower was only able to move 2300 CFM on its own. We also boosted this flow to 3000 CFM for most of the laboratory tests in Phase 2. We were satisfied with the blower wheel, but we increased the motor size from ¾ hp to 1 hp.

Water heater For the glycol/water hydronic heating loop, we replaced the Munchkin condensing water heater with a more affordable, tankless, instantaneous water heater from Takagi. This model, the T-KJr, was recently introduced and is about


2/3 the capacity, cost and size of their standard model. It is also considerably less expensive than the Munchkin water heater.

Expansion Tank For the heating loop we selected a compact in-line expansion tank from Watts that takes up less space than conventional units.

Sump Pump We retained the Taco 0011 but moved it inside the cabinet, whereas in Phase 2 it was hung below the sump.

Drift Eliminator In Phase 2, we noted water droplets being pulled through the tower fan, so in Phase 3 we incorporated a drift eliminator made from CelDEK media. The Phase 3 prototype design is shown in Figure 3-20.


Location Component Location Component A DDC panel L Water spray system B Supply blower and motor M Open condenser C Thermostatic expansion valve N CEWC D Refrigerant cooling aircoil O Ventilation air damper E Ventilation blower and motor P Exhaust air damper F Heater loop circulator pump Q CEWC circulator pump G Tankless water heater R Return air barometric damper H Exhaust air barometric damper S Air filter J Tower fan and motor T Hydronic heating aircoil K Drift eliminator U Main control panel

Figure 3-20: Phase 3 Prototype


3.1.3.2. Design Changes made during Phase 3 As in Phase 2, we made a number of changes to the Phase 3 design after initial testing to improve performance and reliability.

CEWC After we started up the Phase 3 prototypes, we noticed the air filters were wet. The wetness was more noticeable on the field test unit, which had fewer obstructions between the sump area and the VA fan inlet due to the design of its thermoformed plastic CEWC. We did not have this problem in Phase 2, and we determined that the cause was the larger VA blower, which created a pressure differential of about 1.0 inH2O. Negative pressure at the CEWC dry passage exit was pulling water that drained onto the CEWC support rails. To prevent water from entering the VA blower, we segregated the dry passages supplying VA from those pre-cooling air entering the wet passages. The central third of the CEWC was used to pre-cool VA only, and the outer two-thirds were used to pre-cool air for the wet passages. The passages used to pre-cool VA were completely closed to the sump area, to eliminate the possibility of drawing water into the VA blower.

Ventilation Air Blower After modifying the field test CEWC, we detected no moisture on the filters after several hours of run time. However, when we made the same change to the paper CEWC in the laboratory test unit, we continued to draw water into the VA blower. On inspection we found that water was making its way between the CEWC and its casing. Repeated attempts to seal this leak were not successful. We concluded that the cause of the leakage was the large pressure drop created by the VA blower. Also, after changing the CEWC configuration we could not achieve as much VA flow, since only 1/3 of the total dry passage area was now open for VA. We then removed the VA blower and motor to reduce power consumption, thus returning to the original strategy of using the supply blower to draw VA through the CEWC. The Duct Blaster from Phase 2 was installed in its place to measure VA flow rate.

TXV The initial capacity of the laboratory test unit was below our expectations. One cause appeared to be high superheat. We had found in Phase 2 that low or zero superheat increased capacity by about 5% and also increased EER. In Phase 3, we adjusted the TXV but could not reduce the superheat below 20 ºF. The problem appeared to be that the larger evaporator resulted in a large amount of liquid in the condenser. Several approaches emerged from the team to solve this problem. One was to add a receiver tank to reduce the quantity of liquid refrigerant in the condenser.


We were unable to find a suitable R410A receiver tank, probably due to the high pressure of that refrigerant. And opening the TXV all the way with a low charge left the system unstable because it could only adjust itself in one direction when conditions varied. Unable to reduce superheat below 12 °F, we investigated other TXV options. After consulting with TIAX who had selected the TXV, we upsized it from 8 to 10 tons and used a non-MOP unit. MOP, or maximum operating pressure, limits the refrigerant pressure in the system. This makes the system more robust, but limits the TXV’s ability to modulate with varying loads. When DCT ordered replacements for both the lab and field prototypes, they were told by Danfoss that the lead time would be 6 to 8 weeks. DEG conveyed the importance of getting these TXVs promptly so they could be tested as part of the project. Danfoss agreed to build the units quickly and ship them via air freight from their headquarters in Denmark.

3.2. Prototype Fabrication After the team agreed on the initial Phase 3 design changes described in section 3.1.3.1, the design staff at DCT developed a parametric 3D SolidWorks model of the prototype. By modeling all components, DCT could produce the prototypes without mockups or other preliminary design exercises. Drawings of the model were circulated to all team members for input. After a few minor changes, fabrication of the laboratory test unit began.

3.2.1. Laboratory Test Unit Because of the high degree of detail in the SolidWorks model, the production staff at DCT was able to fabricate the laboratory test unit with a minimum of oversight from the R&D department. The first step was to make the sheet metal pieces of the cabinet. These were laser cut from electrogalvanized cold-rolled steel sheets and then formed with press breaks. The sheet metal parts were then welded and fastened together to create the cabinet. Most of the components were installed at the DCT production facility in Buena Vista, Virginia, with final electrical and refrigeration assembly at the R&D test facility in Natural Bridge Station, Virginia. The completed Phase 3 HyPak prototype at the R&D test facility is shown in Figures 3-21 through 3-29.

3.2.2. Photos of Phase 3 Prototype


Figure 3-22: Controls Enclosures

Figure 3-21: Final Assembly


Figure 3-24: Heating and Cooling Aircoils, Condensate Drain Pan, and Sensors

Figure 3-23: Equipment Compartment

Figure 3-25: Open Condenser, Spray Nozzles, Drift Eliminator, and Tower Fan


Figure 3-26: Paper CEWC

Figure 3-29: Paper CEWC and Sump in Operation

Figure 3-27: Top of Paper CEWC

Figure 3-28: CEWC and VA Damper


3.2.3. Field Test Unit At the start of Phase 3, we planned to use a single prototype for both laboratory and field testing. Dave Bisbee of the Sacramento Municipal Utility District (SMUD) had attended a focus group in Phase 2 and was enthusiastic about the HyPak concept. Mr. Bisbee administers SMUD’s Customer Advanced Technologies (CAT) Program, which provides financial support for promising energy efficiency technologies. SMUD agreed to fund a second prototype through their CATs Program. SMUD required that the field test unit be installed in SMUD territory, and that they receive monitoring data. The field test prototype was nearly identical to the laboratory test prototype. The only significant difference was the plastic CEWC to improve reliability and minimize maintenance. The CEWC was built by DEG and shipped to DCT. The VA blower on the field unit was not removed because we were able to seal the plastic CEWC adequately, and we needed VA flow to satisfy the site requirement. The modified CEWC on the laboratory unit could not meet this requirement. The CAT funding also required us to evaluate water treatment options for the CEWC and condenser, an area of concern to the HyPak team as well. SMUD had supported technologies that combat scale buildup in cooling towers and Mr. Bisbee encouraged us to incorporate the Triangular Wave system into the field test unit. This system generates an electromagnetic field in a “deposit controller” that is plumbed into the condenser loop. SMUD had not yet evaluated this product and was interested to see what benefit it offered. At the start of the HyPak project, we had planned to drain the sump once a day to flush out the accumulated hardness minerals. (Because most cooling tower sumps are not drained daily, there is a sizeable market for hardness control systems.). With the addition of the Traingular Wave System, we planned to operate the HyPak system with the water quality control system on for a few weeks and then off for a few weeks and compare the results. To evaluate the water quality and scale buildup, we enlisted the services of BWI Solutions, a company specializing in non-chemical approaches to scale control. BWI will send periodic water samples to an outside laboratory, and continuously monitor conductivity of the make-up and sump water. (As water evaporates and the concentration of hardness minerals increases, the water conductivity increases as well.) Systems such as Triangular Wave claim to prevent scale formation even at concentrations that would otherwise cause scale. The system uses electromagnetic waves to change the ionic behavior of hardness mineral molecules so that they are attracted to each other rather than the metal in the plumbing loop. Instead of precipitating out of solution and onto the metal surfaces, the minerals remain in suspension until the sump is drained. This increases the allowable interval between reservoir drain cycles. Because we had planned to drain the HyPak once a day during cooling season, we felt that the impact of the Triangular Wave system would be minor. Only on days where the system operates at full capacity for long periods will the rate of evaporation be high enough to reach damaging concentrations of hardness mineral. On these days, the Triangular Wave system will ensure that scale is kept to a minimum.


The field test unit is shown in Figures 3-30 through 3-32.


Figure 3-30: Field Test Unit – View 1

Drain

Gas Service

Monitoring Cabinet

Thermostat and sensor

wires


Figure 3-32: Plastic CEWC for Field Test Unit

Figure 3-31: Field Test Unit – View 2

Water supply

Electrical service

DDC panel

Main control panel


3.3. Laboratory Testing Fabrication of the laboratory test unit was completed at the end of July 2003. Team members from DEG and LBNL traveled to DCT in early August to install instrumentation and oversee initial test runs. The objective of the laboratory testing was to evaluate the performance and operating behavior of the HyPak prototype under a variety of operating conditions. In addition, we used the results of laboratory testing to refine and improve the performance and reliability of the HyPak design.

3.3.1. Laboratory Test Plan We based the test plan on the 2000 Air-Conditioning and Refrigeration Institute (ARI) Standard 340/360 (2000): Commercial and Industrial Unitary Air-Conditioning and Heat Pump Equipment. The ARI standard rating condition is intended to indicate RTU performance throughout the United States, and since the HyPak design was tailored to the drier climates of the West, we knew this test would not show its true value for preferred applications. Therefore, we established two operating conditions more typical of peak demand operation in the Western United States. “Western Summer,” simulated typical summer cooling conditions and “Western Maximum” simulated peak design conditions. In addition to ARI 340/360, we followed: 1) ASHRAE Standard 37-1998: Methods of Testing for Rating Unitary Air-Conditioning and Heat Pump Equipment for the details of test setup and instrumentation, 2) ASHRAE Standard 41.1-1986: Standard Methods for Temperature Measurement for the details of temperature measurement; and 3) ASHRAE Standard 51-1999: Laboratory Methods for Testing Fans for Aerodynamic Performance Rating for flow measurement. For details on test conditions and setup, equipment, methodology, sensors, calibration, uncertainty analysis and the equations used, refer to the complete Laboratory Test Plan contained in Appendix F.

3.3.2. Test Conditions The test conditions used in the laboratory testing are described below in Table 3-1.


Table 3-1: Laboratory Test Conditions

Outdoor Air Return Air Test Dry-Bulb °F Wet-Bulb °F Dry-Bulb °F Wet-Bulb °F

Approx. VA Rate (SCFM)

1 Standard Rating Conditions1,2 95 75 80 67 0

2 Modified Standard Conditions1 95 75 80 67 800

3 Western Maximum Conditions 100 70 80 67 800

4 Western Summer Conditions 95 66 76 64 800 Coo

ling

5 Low Temperature Operation1 67 57 67 57 800

6 Standard Rating Conditions3 47 NA 70 NA 800

Hea

ting

7 Low Temperature Operation3 17 NA 70 NA 800 1 According to ARI Standard 340/360-2000, Table 3 2 According to ARI Standard 340/360-2000, 6.1.3.2b and 6.1.3.6 3 Taken from ARI Standard 340/360-2000, Table 3 heat pump rating conditions. The unit is not a heat pump, but these conditions are appropriate to evaluate the heating performance of HyPak.

Supply Airflow. The Supply airflow rate for all tests was 3000 SCFM. For a typical 10-ton unit, section 6.1.3.2a of ARI 340/360 states that supply airflow should be no more than 4500 SCFM. (37.5 SCFM per 1000 Btu/h) However, it allows for a lower indoor air flow rate if so specified by the manufacturer. Ventilation Airflow. Sections 6.1.3.2b and 6.1.3.6 of ARI 340/360 states that only units equipped with an outdoor aircoil (HyPak is not) test with ventilation air. For that reason, run #1 (Standard Rating Conditions) had 0 SCFM of VA. However, HyPak will be much more popular in installations with ventilation air requirements, particularly in California where it is required for all buildings. HyPak will be a direct replacement for a conventional 10-ton RTU with a typical VA rate. Therefore, we attempted to replicate a typical VA rate for a 10-ton RTU, which according to Section 6.1.3.6 of ARI 340/360 is 20% of the SA rate. In a typical installation, a 10-ton RTU will have about 4000 SCFM of SA. For HyPak prototype testing, the VA rate was set at 800 SCFM, or 20% of the supply airflow rate of a 4000 CFM 10-ton unit. External Pressure. Minimum external pressure was 0.30 inH20.1(Table 4)

3.3.3. Laboratory Test Setup The R&D Department at DCT has considerable experience testing evaporative cooling products. DCT builds many custom systems for customers in the HyPak target markets, and the R&D department tests many of these before they are delivered. Despite their location in humid Virginia, they regularly test products at Western design day conditions. The HyPak test setup is shown in Figure 3-33.


Figure 3-33: Laboratory Test Setup Schematic

The HyPak laboratory test unit is shown under test in Figure 3-34.


Figure 3-34: HyPak Unit in Laboratory Test

3.3.3.1. Outdoor Air Loop The largest test apparatus at DCT can condition up to 4000 CFM of outdoor air. We applied this apparatus to the CEWC loop. Because the CEWC exhaust air is virtually saturated, there was no benefit to recirculating this air; hence, it was exhausted to the outdoors. To achieve the specified outdoor air test condition ambient air was first dried using a desiccant wheel with gas recharge. It was then cooled with a 2-stage vapor compression system to remove more moisture. Finally, it was reheated to reach the desired dry-bulb temperature. Airflow rates through the outdoor loop were measured with flow nozzles (Figure 3-36). The outdoor air loop is shown in Figure 3-35.


Enthalpy Wheel and Gas Heater

DX Cooling/ Dehumidification

CEWC Exhaust CEWC Inlet

Figure 3-35: Outdoor Air Loop

Figure 3-36: Flow Nozzle with RTD and Static Pressure Probe

3.3.3.2. Indoor Air Loop Conditioning the indoor air loop was much easier than the outdoor air loop because we could convert the supply air to return air, adding humidity and heat to simulate the building load.


3.3.3.3. Instrumentation We used three different instrumentation setups. For sensors with an electrical output, such as RTDs, thermocouples, and watt transducers, we used a DataTaker DT800 data logger. For pressure measurements, we used an Automated Performance Testing (APT) System from The Energy Conservatory. We measured refrigerant saturation pressures and temperatures with analog gauges on the refrigerant charging manifold and actual temperatures with handheld Type K thermocouple probes. The instrumentation is shown in Figure 3-37.

Figure 3-37: Laboratory Instrumentation

The sensors connected to the DataTaker are listed in Table 3-2.


Table 3-2: DataTaker Instrumentation

Parameter Name Description Sensor Type DB"SA TASR supply air dry bulb temperature RHSA RHS supply air relative humidity

combination RTD/RH

WBSA WBS supply air wet bulb temperature wet-sock RTD, direct reading

DB"RA TARR return air dry bulb temperature RHRA RHR return air relative humidity

combination RTD/RH

WBRA WBR return air wet bulb temperature wet-sock RTD, direct reading

DB"OA TAOR outdoor air dry bulb temperature RHOA RHO outdoor air relative humidity

combination RTD/RH

DB"VA TAVR ventilation air dry bulb temperature RHVA RHV ventilation air relative humidity

combination RTD/RH

WTotal WT total system power watt transducer A WSF WSF supply fan power watt transducer B WTF WTF tower fan power watt transducer B WComp WC compressor power watt transducer A WVF WVF ventilation fan power watt transducer C TNozzle TANZL indoor air nozzle throat temperature RTD with sender DB'SA TASTC supply air dry bulb temperature (thermocouple) type T thermocouple grid DB'RA TARTC return air dry bulb temperature (thermocouple) type T thermocouple grid DB'OA1 TAO1 left side outdoor air dry bulb temperature type T thermocouple grid DB'OA2 TAO2 right side outdoor air dry bulb temperature type T thermocouple grid

DB'VA TAVTC ventilation air dry bulb temperature (thermocouple) type T thermocouple grid

DBEA TAE exhaust air dry bulb temperature type T thermocouple grid

DBRA+VA1 TARV1 mixed return and ventilation air dry bulb temperature 1 type T thermocouple grid



TSump TWSUMP sump water temperature type T immersion thermocouple

THeatSup TWHS water heater supply temperature type T immersion thermocouple

THeatRet TWHR water heater return temperature type T immersion thermocouple

TRef TREF reference temperature RTD, direct reading GPMCond FLC condenser loop flowrate flowmeter GPMHeat FLH water heater flowrate flowmeter CFMGas GF natural gas flow rate gas meter


The APT System has eight built-in pressure transducers and an RS232 output. We connected it to a PC running the accompanying software to log pressures throughout the HyPak prototype. The APT System and DataTaker are shown in Figure 3-38.

Figure 3-38: APT System and DataTaker

We used the APT System to measure the pressures shown in Table 3-3. In addition, we used it to measure the venturi throat pressure of the Duct Blaster after that was installed in lieu of the VA blower. The venturi throat pressure (with a reference port just upstream of the Duct Blaster) can then be converted to CFM using tables provided by the manufacturer of the Duct Blaster, The Energy Conservatory.

APT System

DataTaker

Thermocouple Reference Junction Bath


Table 3-3: Pressure Measurements

Name Description Reference Location

PS supply duct static pressure outdoor air inlet PR return duct static pressure outdoor air inlet PO outdoor air inlet static pressure ambient PVFS ventilation fan inlet cone static pressure outdoor air inlet

PIND indoor loop flow nozzle differential pressure NA

PINS indoor loop flow nozzle static pressure outdoor air inlet

POUTD outdoor loop flow nozzle differential pressure NA

POUTS outdoor loop flow nozzle static pressure outdoor air inlet PE tower exhaust static pressure outdoor air inlet PSUMP sump static pressure outdoor air inlet PCEWCE CEWC exhaust static pressure outdoor air inlet PSF supply fan differential pressure NA

3.3.4. Laboratory Test Results Laboratory testing began in mid-August 2003 and continued until early March 2004. To improve performance and EER the compressor, TXV and CEWC were all replaced or modified, each leading to several weeks of downtime. However, by January we had explored the possible changes; any further improvements would have required modifying the prototype beyond the scope of Phase 3. Although we could not repeat the outstanding performance of Phase 2, we learned that some Phase 2 data were inaccurate. The power factor applied to the power measurements was incorrect, resulting in compressor power consumption 20% less than actual. Also, airflow was boosted through the indoor and outdoor loops in Phase 2, and the power required was not included. For a complete discussion of the laboratory test results, see Section 4.1.1. The complete test data are contained in Appendix G.

3.4. Field Testing After the plastic CEWC was reconfigured (described in section 3.1.3.2), the field test unit was shipped from DCT to the field test site near Sacramento, California in mid-November 2003. The field test unit was installed by Airco Commercial on the Lionsgate Hotel and Conference Center at McClellan Business Park, about seven miles northeast of Sacramento. The building is the former Officers’ Club of McClellan Air Force Base. As part of the decommissioning and privatization of the former base, the building has undergone a complete renovation, including conversion from a 100-ton central heating and cooling system to ten RTUs. The HyPak field test unit was installed in addition to nine Trane units to meet this requirement.


The objective of the field test was to gather real-world experience and data from the first HyPak prototype to be installed in the field. In addition to collecting quantitative data, we expect to evaluate installation, operation, maintenance and reliability of the HyPak design, with an emphasis on preventing scale build-up on wetted surfaces. We worked with the engineer of record for the Lionsgate project to get his input, and to satisfy all of his requirements. The field test complemented the data gathered under controlled laboratory conditions. A conventional RTU serving a similar zone in the same building was monitored to provide a side-by-side comparison. After installation, we ran basic performance tests, but it was a challenge to evaluate cooling performance during late winter. We set the thermostat of the conventional RTU in the adjacent zone to heating to generate a cooling load. After we started the unit, we measured the return airflow rate during maximum cooling operation. We could then use that airflow rate to determine the unit capacity and EER at any time when it was operating in the maximum cooling mode.

3.4.1. Field Test Plan The field test plan was based on prior DEG field monitoring programs. For details on test conditions and setup, equipment, methodology, sensors, calibration, uncertainty analysis and the equations used, refer to the complete Field Test Plan contained in Appendix H.

3.4.2. Field Test Setup The field test unit was installed on the Lionsgate Hotel and Conference in the same manner as a typical RTU. The only changes were:

• The HyPak unit weighs more than a typical RTU of the same size due to its larger cabinet and the water in the sump. Therefore the trusses under the HyPak needed to be larger.

• Unlike conventional air-cooled RTUs, HyPak requires a water source. A 1” copper water line was installed.

• The Trane RTUs are designed to have the electrical, natural gas and condensate drain lines within the curb. This minimizes roof penetrations and lines on the roof. The HyPak unit required separate electrical and gas lines to penetrate the roof.

• Because of the sump drains, HyPak required a 2” PVC drain line. The condensate is also plumbed into this line.

The field test unit and the baseline RTU were monitored with a DataTaker DT500. The DataTaker sensors are listed in Table 3-4.


Table 3-4: Monitored Field Test Sensors

Parameter Name Description Sensor Type DBSA TAS Supply air dry bulb temperature RHSA RHS Supply air relative humidity

Combination RTD/RH

DBRA TAR Return air dry bulb temperature RHRA RHR Return air relative humidity

Combination RTD/RH

DBOA TAO Outdoor air dry bulb temperature RHOA RHO Outdoor air relative humidity

Combination RTD/RH

DBVA TAV Ventilation air dry bulb temperature RHVA RHV Ventilation air relative humidity

Combination RTD/RH

DBSABL BTAS Baseline unit supply air dry bulb temperature RHSABL BRHS Baseline unit supply air relative humidity

Combination RTD/RH

DBRABL BTAR Baseline unit return air dry bulb temperature RHRABL BRHR Baseline unit return air relative humidity

Combination RTD/RH

TSump TWSUMP Sump water temperature RTD (immersion) SComp SC Compressor status On/off status SSF SSF Supply fan status On/off status STF STF Tower fan status On/off status SVF SVF Ventilation fan status On/off status SCP SCP CEWC pump status On/off status SHP SHP Heater pump status On/off status SCompBL BSC Baseline unit compressor status On/off status WTotal WT Total system power Watt transducer A WTotalBL BWT Baseline unit total system power Watt transducer B CTYSump C1 Sump water conductivity Conductivity sensor GPMCond FLC Condenser loop flowrate Flowmeter

Pressure measurements were made with a DG-3 digital manometer from the Energy Conservatory. We used a Blower Door from the Energy Conservatory to measure the return airflow rate to the HyPak unit. The Blower Door is a calibrated venturi with an integrated axial fan. We mounted it on a plenum attached to the return register and used the variable speed axial fan to create atmospheric pressure inside the plenum, ensuring that the flow through the Blower Door was the same as it would have been if the plenum and Blower Door were not installed. We used a table supplied by the Energy Conservatory to convert the pressure in the venturi throat to CFM. Unlike the laboratory unit, the VA blower was not removed and replaced with the Duct Blaster. We were able to seal this unit well enough to eliminate water droplets from the VA. Before replacing the VA blower with the Duct Blaster in the laboratory unit, we sought a pressure measurement that could reliably and accurately be used to indicate VA flow rate through the blower. The configuration of the test setup was modified to a once-through arrangement where the Duct Blaster could be used to measure VA flow rate. The


flow rate could then be used calibrate a pressure measurement if we could find a suitable pressure signal. We ran the VA blower at several speeds and measured the flow rate through the Duct Blaster and the static pressures at several locations around the blower. We found a strong correlation between the static pressure in the plenum upstream of the VA blower and the VA flow rate. It is shown in Figure 3-39.

VA Flow Rate vs VA Blower Inlet Pressure

0

50

100

150

200

250

300

350

400

0.00 0.50 1.00 1.50 2.00 2.50

Inlet pressure (-in WC)

Flow

(SC

FM)

Figure 3-39: Data Used to Correlate Pressure to VA Flow Rate

This data was used to determine the VA flow rate of the field test unit once it was installed.

3.4.3. Field Test Results We spent a considerable amount of time getting the field unit operational. Because the HyPak unit was only one part of a large project to renovate the HVAC system at the Lionsgate Hotel and Conference Center, we often had to wait a week or more before Airco could address our concerns. We had to rely on them to install the water, gas and drain lines, as well as the electrical service and the thermostat wire. Often these had to wait for major tasks, such as installation or removal of ducts. The engineer of record on the Lionsgate project had a number of concerns about the HyPak unit. He originally specified a Trane RTU for this zone, so we had to prove to him that our unit could satisfy the design requirements. In particular, he was concerned that our unit had a smaller compressor than the Trane unit. He was satisfied once we provided him with a cut sheet and written description of the how HyPak operates. We only began to assess the performance of the HyPak field unit at the time of the writing of this report. We measured the indoor airflow and collected sensor data to


calculate a capacity and EER, but it was only at one outdoor condition. Data collected during the upcoming cooling season will give a better idea of how the HyPak unit is performing as compared to the baseline Trane RTU and with respect to extreme outdoor air conditions. For a complete discussion of the field test results, see Section 4.1.2. The complete field test data is contained in Appendix I.


4. Results and Discussion

4.1. Product Results Both laboratory and field test results are described in this section. The laboratory test results summarize performance of the HyPak prototype under controlled conditions. Those conditions focused on full load operation during extreme dry bulb and wet bulb outdoor temperatures. In the field test, gathering numerical data was only one part of the task. Interaction between the HyPak development team and HVAC engineers and installers generated several insights and suggestions that will be incorporated into the production product, engineering documentation and sales literature. The field test also highlighted several building code and controls logic issues.

4.1.1. Laboratory Test Results Laboratory test data were collected from August 2003 to March 2004. The early test results were disappointing and prompted the design improvements discussed in Section 3. Only data collected after implementation of the design improvements are included in this report.

4.1.1.1. Summary The ARI standard rating “nameplate” capacity and EER were 80,300 btu/hour and 14.65, respectively. The gross cooling capacity at ARI Standard Rating Condition was 87,800 btu/hour, or 7.3 tons. Capacity remained steady through a variety of demanding outdoor conditions, ranging from 6.8 to 7.4 tons. EER results varied from 13.46 to 18.15 (row 17 of Table 4.1). As in Phase 2, performance increased with rising ambient temperature. With outdoor conditions of 106 °F DB and 66 °F WB, we recorded an EER of 17.31 and capacity of 85,900 btu/hr, or 7.2 tons. This capacity is roughly comparable to a conventional air-cooled 10 ton RTU at these conditions. The maximum EER recorded was 18.2, a value achieved with a ventilation air boost. As we found in Phase 2, the ARI standard rating test is not a good indicator of the true performance of the HyPak system because it includes no ventilation air. Since nearly all RTUs are required to provide ventilation air, the ARI test should not be used as the sole basis for RTU selection. Complete test data are included in Appendix G. The laboratory cooling test data are summarized in Table 4-1. The test runs were conducted at the conditions and parameters described in Section 3.3.2. In addition to the ARI Standard Rating Condition (column A), we tested the HyPak prototype at three other conditions. The Modified ARI Standard Rating Condition (column B), adds ventilation air to column A. The Western Summer Condition (column C) replicated the peak hours of a typical, but not design, day for many western cities. Western Maximum Conditions (column D) matched peak hours of a design day for those


same Western cities. It is similar to typical, non-design days for the hottest cities in the West, such as Phoenix and Las Vegas.

Table 4-1: Laboratory Test Cooling Results

A B

Units1 OFF OFF OFF OFF ON OFF OFF ON2 CLOSED OPEN CLOSED OPEN OPEN CLOSED OPEN OPEN

rate SCFM 2183 2189 2193 2189 2166 2184 2243 2146DB ºF 96.4 95.5 94.9 95.6 94.8 104.4 104.6 106.1WB ºF 74.4 74.7 68.5 74.5 67.4 71.4 71.1 66.1DP ºF 65.3 66.4 54.6 66.0 52.0 54.8 54.1 38.4

enthalpy btu/lb 37.88 38.23 32.77 38.06 31.83 35.18 34.98 30.84rate SCFM 2987 2991 3003 3005 3005 2993 2997 2993DB ºF 80.3 79.9 76.6 75.8 76.6 79.7 78.7 79.9WB ºF 65.7 66.0 63.3 63.8 63.4 64.8 64.1 65.1


enthalpy btu/lb 25.33 25.99 23.92 23.98 23.97 24.49 24.11 24.99rate SCFM 0 363 0 430 795 0 363 744DB ºF 79.6 79.9 76.1 78.9 77.6 78.5 79.5 80.7WB ºF 70.6 71.9 63.4 71.3 62.1 64.5 66.2 62.5DP ºF 66.8 68.6 56.3 68.1 62.1 56.9 59.3 51.2


enthalpy btu/lb 31.30 31.71 29.33 29.81 29.63 30.59 29.98 30.72rate SCFM 2987 2991 3003 3005 3005 2993 2997 2993DB ºF 58.0 58.6 55.8 55.8 55.6 57.0 56.6 58.0RH % 96.0 97.0 95.0 97.0 95.0 95.0 95.0 95.0WB ºF 57.5 58.3 55.2 55.5 55.0 56.3 56.0 57.3

enthalpy btu/lb 24.78 25.29 23.30 23.52 23.17 24.03 23.80 24.659 ºF 79.5 78.5 76.4 77.9 77.0 77.5 75.5 78.710 ºF 5.1 3.8 7.9 3.4 9.6 6.1 4.4 12.611 W 5484 5511 5438 5621 4974 5478 5466 4963

W 730 793 745 818 720 704 800 659W 677 656 616 659 218 673 652 219W 3762 3734 3757 3818 3706 3781 3686 3875

12 Btu/h 0 4036 0 5405 13684 0 6369 876613 ºF NA 2.2 1.7 2.1 10.1 2.0 5.2 12.814 Btu/h 87762 86464 81512 85010 87351 88353 83392 8170515 Btu/h 80344 76958 73197 78779 76583 82236 79229 7714416 Btu/h 80344 80994 73197 84184 90266 82236 85598 8591017 14.65 14.70 13.46 14.98 18.15 15.01 15.66 17.3118 ºF 51 52 52 49 50 52 52 5219 ºF 112 102 112 100 107 102 102 10220 ºF 6.8 8.5 3.0 5.7 6.0 4.1 4.7 8.021 ºF 26.3 16.9 28.9 16.9 22.5 17.7 18.7 15.0

7

8

C D

3

4

5

6

Western Summer Conditions

Value

Test ARI Standard Rating

Conditions

Modified ARI Standard

Conditions

Western Maximum Conditions

Outdoor Loop BoostVA Damper

Sump temp

Outdoor Air

Return Air

Supply Air

Ventilation Air

Mixed Return and Ventilation Air

Coil Outlet Air

CEWC approachTotal powerSupply blower powerTower fan powerCompressor powerCEWC VA coolingCEWC dew point riseGross compressor capacityTotal capacity w/o CEWCSystem total cooling capacityTotal EEREvaporating temperatureCondensing temperatureSuperheatingSubcooling

Conditions at various locations in the HyPak prototype are shown in rows 3 through 8. The most critical locations, return and supply, had wetted RTDs to measure wet-bulb directly. Other locations used solid-state relative humidity sensors. For dry-bulb measurement, all locations had thermocouple grids with single RTDs for backup.


4.1.1.2. Discussion “Gross compressor capacity” (row 14), the value used to rate RTU capacity by manufacturers, was determined from the difference in enthalpy immediately before and after the cooling coil. The “total (cooling) capacity without the CEWC” (row 15) also includes the enthalpy rise of the supply air after passing through the supply blower, which slightly increases the dry bulb temperature. The “system total cooling capacity” (row 16) adds the contribution of the indirect evaporative cooling of the ventilation air in the CEWC (CEWC VA cooling, row 12). For runs with the VA damper closed, there is no indirect evaporative cooling in the CEWC and no VA added to the conditioned space. The VA Damper (row 2) allows ventilation air to enter the indoor loop after being pre-cooled in the dry passages of the CEWC. A separate damper controls building EA leaving the indoor loop and entering the sump. The exhaust air (EA) makes up for the ventilation air (VA) that is drawn off from the CEWC so that the flow rates in the indoor loop and through the tower fan remain constant. These dampers are linked and driven by the same actuator. Tests with the damper closed have no VA. For the Western Summer and Western Max runs, we tested the unit without VA in the first test of each condition, and with VA in the other two tests, to evaluate the impact of outdoor dry-bulb and wet-bulb on the sump temperature, condensing temperature and compressor capacity. This comparison also shows the EER benefit of indirect evaporative VA cooling in the CEWC. In both conditions, EER increased as VA flow increased. As described in Section 3.1.3.2, we removed the VA blower because it was pulling water spray from under the CEWC into the supply air. This meant that we could only use the supply blower to draw VA through the CEWC dry passages. The amount of VA did not drop much after we removed the VA blower, leading us to conclude that the air was choked by the exit from the dry passages. (Only 1/3 of the CEWC was used for VA precooling in Phase 3.) Another possibility was that the strong negative pressure of the VA blower was causing the walls of the passages to deflect inward, reducing the flow area. In an attempt to simulate how HyPak would perform with more VA flow, we used the external blower in the test equipment to create a positive pressure of 0.3 inH2O at the outdoor air inlets. This is noted in Table 4-1 as “Outdoor Loop Boost” (row 1). For both Western Conditions, we ran three tests. The first had no VA, the second had the amount of VA drawn by the supply blower, and the third had the Outdoor Loop Boost. With the positive pressure of the external boost, the passages may have been opened further, increasing the flow area. The extra blower energy of the external boost was not included in the EER. If this were taken into account, we estimate the EER would be approximately .8 points lower than the values shown in Table 4-1.

The CEWC performance was similar or better than in Phase 2. The “CEWC approach” (row 10) is the difference between sump water temperature (row 9) and outdoor air wet-bulb temperature (row 3), and is a good measure of cooling tower performance. Cooler sump water lowers condensing temperature (row 19), which results in higher compressor capacity and efficiency. In Phase 2, the CEWC approach was in the low teens. For most Phase 3 test runs, the CEWC approach was less than 10 °F, and in several cases less than 4 °F. Given that the theoretical limit of a conventional cooling tower without any cooling


load is the wet-bulb temperature of the outdoor air (approach equal to zero), the performance of the CEWC as compared to a cooling tower is impressive. Although it has not been tested without a cooling load, we suspect that the CEWC can attain sump temperatures below the outdoor air wet bulb temperature. We believe the cause of this closer CEWC “approach” is cooler water entering the CEWC, as more evaporative cooling occurred above the CEWC compared to the Phase 2 design. The reported performance of the refrigeration system for Phase 3 was slightly lower in comparison with Phase 2, chiefly because of higher condensing temperatures that resulted from the changed condenser design. The Phase 2 prototype used a helical coaxial condenser that could not easily be cleaned in the event of hardness mineral accumulation in the narrow water passages. To reduce water loop pressure drop and facilitate service in hard water areas, we substituted an “open coil” condenser in Phase 3. But reviewing Phase 3 data makes clear that despite lower sump temperatures and adequate subcooling (indicating that the refrigerant is fully condensed, which in turn indicates that the condenser is large enough), condensing temperatures are typically at least 10°F higher in Phase 3 than they were in Phase 2. We measured about 5 ºF more subcooling (row 21) in Phase 3 than in Phase 2. Although subcooling is important to ensure that vapor does not enter the TXV, excessive subcooling reduces capacity and efficiency by allowing too much liquid in the condenser. The real culprit is the open design, in which warmed, saturated air leaving the CEWC contact the condenser underside, while the coolest water is sprayed over the top. The forced counterflow design of Phase 2 provided better film coefficients and a more favorable temperature regime for heat transfer. A cleanable, closed counterflow condenser would combine the advantages of the Phase 2 and Phase 3 designs. Eliminating the open condenser would also reduce the overall height of the HyPak unit, an important concern among building owners and architects. Refrigeration system performance also suffered slightly from excessive superheat (row 20). We were not able to adjust the TXV to reduce superheat below the values shown in Table 4-1. In Phase 2, we used an electronic TXV from Sporlan that allowed complete control over the refrigeration flow rate. Since the Sporlan unit was quite expensive and we had not needed its full capabilities in Phase 2, we ordered a lower-cost TXV from Danfoss for Phase 3. The Danfoss unit is designed to maintain higher superheat values than we implemented in Phase 2. In future HyPak products we anticipate adding an alternate TXV that allows reduced superheat.

“CEWC Dew point rise” (row 13) is an indicator of moisture addition during the VA precooling in the dry passages of the CEWC. (It is not calculated for the two runs with zero VA flow rate.) If there were no leaks inside or around the CEWC, the dew point rise should have been zero for all test runs. There is considerable uncertainty associated with measuring dew point since both the OA and VA locations only had single-point RH sensors instead of the more accurate wet-bulb thermometers used in the critical RA and SA locations. There appeared to be a slight increase in dew point across the dry passages for all test runs, perhaps due to an offset between the RH sensors.


The laboratory performance of the Phase 3 HyPak prototype was poorer compared to performance reported for the Phase 2 unit for the following reasons:

• Our Phase 2 compressor measurements were higher by about 20% due to an erroneous power factor adjustment. In Phase 3, we used more accurate power sensors.

• The CEWC modification lowered performance during the ARI Standard Rating Condition test because ⅓ of the dry passages could not be used; Without VA flow, there was no air movement through the central ⅓ of the dry passages. In other tests, the modifications limited the amount of VA to approximately 400 CFM. In Phase 2, the higher VA flow rates (up to 1150 CFM), resulted in more than 1.5 tons of indirect evaporative cooling. This change reduced both capacity and EER.

• The refrigeration system did not operate as well for reasons described above. Because the ARI Standard Rating Condition (column A) does not include VA, it offers little insight into HyPak performance during anticipated field operation. A more realistic condition is the Modified ARI Standard Rating Condition (column B), which has the same outdoor conditions but does include ventilation air. It is a good indication of HyPak performance nationwide, but is not typical of the target market for HyPak – the arid west. That area is better represented by the Western Conditions tests. Table 4-2 compares one run from each of these conditions. The run chosen has no external boost and the VA damper open.

Table 4-2: Summary of Representative Cooling Test Runs

UnitsOPEN OPEN OPEN

rate SCFM 2189 2189 2243DB ºF 95.5 95.6 104.6WB ºF 74.7 74.5 71.1rate SCFM 2991 3005 2997rate SCFM 363 430 363DB ºF 79.9 78.9 79.5WB ºF 71.9 71.3 66.2

ºF 78.5 77.9 75.5ºF 3.8 3.4 4.4W 5511 5621 5466

Btu/h 4036 5405 6369ºF 2.2 2.1 5.2

Btu/h 86464 85010 83392Btu/h 76958 78779 79229Btu/h 80994 84184 85598

14.70 14.98 15.66ºF 52 49 52ºF 102 100 102

ValueTest Modified ARI

Standard Western ConditionsSummer Maximum

VA Damper

Outdoor Air

Supply Air

Ventilation Air

Sump tempCEWC approachTotal powerCEWC VA coolingCEWC dew point riseGross compressor capacitySystem capacity w/o CEWCSystem cooling capacityTotal EEREvaporating temperatureCondensing temperature


Comparing these three runs, it is clear that HyPak excels in hot and dry outdoor conditions – the same conditions that cause lowered capacity and EER for conventional air-cooled RTUs. HyPak can maximize occupant comfort while minimizing peak load in hot dry conditions. The CEWC modification resulted in two negative consequences. First, the maximum amount of VA that could be drawn through the dry passages was significantly reduced. Second, there were ⅓ fewer passages available to lower the dry air wet bulb before it entered the wet passages. During test runs with VA flow, an equal amount of building exhaust air entered the wet passages, and the flow through the non-VA dry passages was about the same as in Phase 2. However, for the ARI Standard Test, which has no VA, more air was forced through each non-VA dry passage, reducing CEWC performance. The results of the heating mode test are shown in Table 4-3.

Table 4-3: Heating Test Results

UnitsOPEN

rate SCFM 1028DB ºF 46.9rate SCFM 2986DB ºF 70.7rate SCFM 2986DB ºF 81.0rate SCFM 363DB ºF 53.5rate SCFM 2986DB ºF 60.9rate SCFM 2986DB ºF 80.5

W 1152Btu/h 2598Btu/h 63371Btu/h 67589

Heating

Heating capacityAircoil heating capacityCEWC heat recoveryTotal power

Supply Air

Ventilation Air


Coil Outlet Air

VA Damper

Outdoor Air

Return Air

ValueTest

The heating performance is satisfactory for most target markets. The water heater setpoint can be increased to further increase capacity. It can be adjusted from 105 to 180 °F, and we used the factory default of 120 °F for our tests. We ran the heating test with the supply blower on full speed to maximize capacity. This also contributed to the low SA temperature. The field test heating controls operate with 2000 CFM during occupied periods to maximize SA temperature, and 2500 CFM during unoccupied periods to maximize capacity. When preparing the test plan, we analyzed the uncertainty of our anticipated results. We determined that our capacity calculation would have about double the uncertainty that would result from strict adherence to the ARI and ASHRAE standards. This was mostly


due to temperature measurements with 4% and 5% uncertainty for dry-bulb and wet-bulb respectively. ASHRAE 37 calls for 2% uncertainty for both, which requires instrumentation an order of magnitude more expensive than allowed in our budget. Our power measurement was slightly more accurate than required, so our overall EER uncertainty is about 50% greater than presumed for ARI and ASHRAE standards. The test plan called for an isothermal water bath for the reference junction of the thermocouples. We installed the isothermal junction per the test plan and recorded good data at first. However, after about a month of testing the thermocouples began to produce inaccurate readings. After several days of unsuccessful troubleshooting we were forced to abandon the isothermal water bath and rely on the onboard temperature sensor wiring block at the datalogger wiring block. This change increased the uncertainty by 0.5 °F. Table 4-4 shows the final uncertainty values.

Table 4-4: Uncertainty Analysis

Parameter Capacity EER Uncertainty with strict adherence to ASHRAE 37

4.2% 6.2%

Uncertainty anticipated in HyPak Laboratory Test Plan

8.1% 8.9%

Uncertainty calculated after testing 15.4% 16.2% Based on these uncertainties, the HyPak ARI “nameplate” capacity is 6.70 ± 1.03 tons, and the EER is 14.65 ± 2.37. However, for our calculated capacity or EER to be low by the amount shown in Table 4-5, each sensor would have to be at the far end of its calibrated range, and all would have to err toward lower performance. In all likelihood, our calculated values are reasonably accurate because of the number of sensors involved, and the steps we took to compare sensors throughout the tests. LBNL was instrumental in developing the laboratory test plan, particularly the selection of instrumentation and assessment of uncertainty. Following the laboratory testing, LBNL evaluated the test results and determined that we had taken all reasonable steps to measure HyPak performance in an unbiased and accurate manner. A memo from LBNL validating the laboratory testing is included in Appendix J.

4.1.2. Field Test Results The field test unit was installed on the Lionsgate Conference Center in the Sacramento, California area where it serves a ballroom. The building HVAC system was converted from a 100-ton central heating and cooling system to ten individual 10-ton RTUs. The HyPak field test unit was installed as one of the RTUs. The other nine are conventional air-cooled units. Installation of the field test unit took place during the winter months, which made it difficult to collect cooling data. However, the month of March was unseasonably warm and we were able to operate the unit in cooling mode with a cooling load and warm


outdoor temperatures. The results are summarized in Table 4-5. Complete field test is contained in Appendix I.

Table 4-5: Field Test Data

DB ºF 86.7WB ºF 57.0DB ºF 54.1RH % 61.5WB ºF 41.5

enthalpy btu/lb 15.93DB ºF 71.4RH % 61.5WB ºF 54.0

enthalpy btu/lb 22.58CFM 2600

btu/hr 77900W 5531

14.1

Outdoor Air

Supply Air

EER

Return Air

Indoor Air Flow RateCapacity

Total Power

We expected the capacity and EER to be higher for this run, given the outdoor air temperature. However, the return air was cooler than in our laboratory testing, so the evaporating temperature was lower, reducing efficiency. In addition, no ventilation was supplied, therefore there was no benefit from the CEWC. (During the summer months, the facility manager will increase the setpoints to at least the mid-70’s °F.) After the field test unit was installed, we had to troubleshoot several sub systems. Adjustments were made quickly to get the unit on-line. We intend to make several changes to the refrigeration system in the near future to improve reliability and performance. Also, we will continue to monitor the unit and evaluate system performance. Other aspects of the field test, especially water quality and scale control, will require at least an entire season of cooling data before we can draw conclusions. In addition to deriving the Table 4-5 performance data, we noted the following during the installation and initial operation of the HyPak field test unit:

• The engineer of record on the Lionsgate project was concerned that the HyPak unit had a smaller compressor than the conventional units. He was satisfied once we provided more detailed design and specification information.

• An accumulator should be installed to simplify maintenance. • The access doors need better seals and should be easier to remove quickly. • The DDC control program required a little fine tuning, but otherwise was ready

for operation. Further monitoring of the unit may lead to further refinement of the controls sequence.

• The conventional units installed on the other 9 zones locate all connections inside the curb. This eliminates additional roof penetrations, of which there were five for HyPak. We should include this feature in the production HyPak.

• An external convenience 120 VAC jack would be helpful.


• An optional larger motor, probably 2 hp, will be required for many duct systems. • HyPak is about 30% heavier than a 10 ton air-cooled RTU and requires stronger

structural supports. • The cantilevered sump is effective for controlling leaks. No leaks have been

detected inside the curb.

4.1.3. Product Maintenance The field unit has not been operating long enough to generate viable information about HyPak maintainability. However, hundreds of hours of laboratory operation in Phases 2 and 3 have indicated that the following areas will require attention during HyPak product life:

• CEWC. The plastic plates in CEWC on the field test unit will not corrode. However, they may develop scale buildup. Some plastic indirect evaporative heat exchangers do not need to be cleaned because the flutter of the plate causes the scale to flake off during operation. Regardless, production HyPak versions must have an easy way to remove the CEWC. Easy removal mandates foam seals and no caulking.

• Condenser cleaning. Future HyPak products will likely return to a closed condenser heat exchanger. Although scale buildup should be kept in check with one or both of our mitigation strategies, the condenser must be cleanable. Refrigeration charge. The Phase 3 HyPak design used a “critically charged” system, in which a small overcharge or undercharge will adversely affect performance. With the addition of an accumulator to hold excess charge, the window in which the system operates with maximum efficiency is much larger. As such, the HyPak refrigeration system should not require more maintenance than a conventional RTU.

• Hydronic heating delivery system. The Phase 3 units were charged with a water/glycol blend to prevent freezing. Repairs or leaks will require the system to be recharged in the field with a pump. The circulator pumps are reliable, and their motors can be replaced if needed without removing the pump from the system.

• Drift eliminator replacement. The Phase 3 drift eliminator is cellulose-based (Munters CelDEK), which will probably require replacement about every five years. A plastic version could eliminate this task.

• Air filter replacement. The filters in HyPak are scheduled to be changed annually, and could even operate for two years before pressure drop became problematic. This is a longer service life than the low quality 1” thick filters found in conventional RTUs.

• VFD damage caused by power surges. The installer has experienced power surge damage with the brand of VFD used in HyPak.

• Supply blower motor. Because HyPak has a direct drive motor, there is no need to replace belts or adjust sheaves.


4.1.4. Product Reliability More field operation is required to assess HyPak reliability. Reliability concerns include:

• Scale buildup due to hardness minerals. The lower efficiency of the Phase 3 open condenser means that it may operate at or above the threshold (~130 °F) at which aggressive scale buildup becomes a concern. The field test offers an opportunity to evaluate the scale issue. A closed counterflow condenser heat exchanger should result in much lower water temperatures and reduce scale buildup.

• Refrigeration charge. Once the receiver is installed, the refrigeration system should be as reliable as a conventional RTU.

• Water leaks. The cantilevered sump, should minimize the danger of a chance leakage that causes building damage.

• The hydronic heating delivery system. Leaks from freeze damage are possible if the system is recharged with water instead of glycol. Clear service instructions, and a warning label, should prevent this error.

4.2. Assessment of Commercial Viability and Market

Potential 4.2.1. Customer Analysis Although RTU’s are owned by building landlords or tenants, their owners are not the only key decision makers regarding RTU purchases. Building designers (mechanical engineers), HVAC contractors and facility managers can also be key players in the purchase decision. Depending upon the level of expertise and involvement of the facility owner and operator, the contractor’s or engineer’s recommendation may be the de facto purchase decision. Advice may also be sought from utility representatives and architects. Consequently, selling RTU’s is typically a complex process, involving multiple players. A long-term marketing campaign is needed to get established in a market. Elements of an effective RTU marketing campaign include:

• Selection of a regional distributor that will stock the product and provide warranty service and parts

• Training of contractors • Meetings with utility personnel to familiarize them with the product and gain

inclusion in appropriate incentive programs • Provision of monitoring data relevant to that area, or installation and monitoring

of units at key sites in the region • Establishment of a regional maintenance capability • Advertising • Contact with key players at industry gatherings and one on one:

§ Landlords and tenants § Design professionals, particularly those practicing sustainable design § Facility managers § HVAC contractors § US Green Building Council and other industry associations


For HyPak commercialization to be successful, specific marketing strategies will be needed for high potential markets. The initial target market is California, followed by other western states.

4.2.2. Focus Group Responses Three focus group sessions were held in September, 2002 introducing HyPak to key players in the Sacramento, CA and Las Vegas, NV markets. Participant backgrounds covered a wide range of the HVAC Industry, yielding good insight across the field. The participant’s professions are listed in Table 4-6.

Table 4-6: Focus Group Attendees

Profession Number of Participants Building Owner 1 Contractor 7 Developer 1 HVAC Engineer 6 Manufacturer Representative 9 Utility Representative 1 Facility Manager 1 Property Manager 1 Total 27

During the stakeholder sessions there was some discussion regarding the design details of the system, and the source of the predicted energy savings. The energy savings claims were taken at face value in the sessions, but many participants noted that they have yet to be proven. The general consensus was that if the promised energy savings can be achieved, the product could be very interesting, but many concepts look fine on paper, while actual field performance can be quite different. There was general agreement that several units must be put into a field test to show “real” savings in each particular climate. Demonstrated savings of an actual unit in operation is a strong selling point. Focus group participants said they would greatly value having data from a local test sight so that they can tell others involved in the purchase decision, “buy this unit, it will save you money”.

4.2.3. Concerns The two areas that caused the most concern were cost and maintenance. Some members felt that while first cost was important, consumers are becoming more educated, and life cycle cost is gaining greater attention. This point was not agreed to by everyone. Many felt first cost was by far the most important issue in the market, regardless of what people say in other forums. They felt that building owners rarely care about energy savings, as they either sell the building quickly, or pass the costs on to the tenants. One facility manager countered that they have just started a program in Sacramento where the owners and tenants are working together to improve the efficiency of their buildings, providing energy savings for the tenants, and improved buildings for the owners.


The bottom line, as one would expect, was that for the average customer, the lower the cost premium, the easier the sale. Again, the utility representative mentioned the incentive programs available in California to offset cost premiums and his interest in providing such an incentive for the HyPak once it reaches the market. Maintenance was a major concern in both cities. It was stated that one of the most valuable attributes of existing packaged rooftop units is their reliability. As one participant stated, “they sit on the roof for 15 years and run with no maintenance other than filter changes”. The added complexities of the HyPak, as compared to a conventional unit, raised questions about additional maintenance required. Concerns were mainly focused on the water-side of the unit, and the fact that an “unconventional” unit may be too much of a challenge for most maintenance staff. All groups felt that the manufacturer could do a great deal in this area to alleviate these concerns. By offering:

• A maintenance support contract • Appropriate training • Local support • Off the shelf, in stock parts • Good, clear documentation

These needs are expressed very strongly for school applications, where budgets are tight, and maintenance crews are not well trained. In schools, for example, the maintenance staff frequently consists only of janitors, who can be trained to change filters, but nothing more. The maintenance issue seemed to be the biggest area of concern, and potentially the biggest barrier, for all the participants associated with school applications. One attractive feature of the HyPak is the ability to offer improved indoor air quality (IAQ) relative to a conventional rooftop unit. However, IAQ did not generate much discussion. It was agreed that it is important, that there is concern about it, and many participants felt that more ventilation is the key to improving IAQ. Some participants noted that while IAQ is a great concern in the abstract, customers are unsure about exactly what to do about it. A desire was expressed in both cities to expand the range of outdoor air to 100%, which is not available in the current HyPak design.

4.2.4. Reaction and Conclusions The overall reaction to HyPak was quite positive. There was general agreement that the HyPak concept fills the need for an energy efficient rooftop air conditioner with a well thought-out, novel design. There was genuine excitement, particularly in Sacramento, that the HyPak was particularly designed for the hot, dry climate of the west, and the dollar savings that this unit could represent in such climates. While most of the discussion portion of the sessions focused on the importance of energy savings and concerns over maintenance issues, quantitative results of voting show that cost, particularly first cost, is the most important issue in getting a new unit into the field. Concerted efforts must be made to minimize the cost premium of the HyPak in order for it to be a success.


The strong importance of reliability was also emphasized in the voting, ranking its importance second to cost. Again, efforts in the design stage should take into consideration the importance of reliability and maintainability. Discussion results highlighted the need for minimal and simple maintenance tasks, particularly in school installations, keeping in mind the limited skills of many maintenance staff. It was the opinion of both groups that the manufacturer can play a pivotal role in this area by having a responsive, knowledgeable, local representative support this product. Offering a factory maintenance/service contract, as well as training, would also help ease concerns that may be a barrier to purchasing the unit. The California market seemed the most receptive to the HyPak concept. The Sacramento Municipal Utilities Division representative expressed a strong interest in becoming involved in the program. He was interested in supporting a field test program in the Sacramento area, and suggested that more California utilities be made aware of the program by introducing it through the EPAC committee. The value of field-testing to prove performance and reliability was also emphasized. Most agreed that final judgments should be reserved for after the HyPak has proven itself in the field. Field test results would also be invaluable when convincing potential customers of the benefits of the unit. Results of the focus group sessions show that HyPak addresses a genuine desire by the HVAC community in the Western U.S. for a high-efficiency, reliable product that specifically addresses their needs. There are three essential issues that must be addressed for the HyPak to succeed in the marketplace: the production unit must deliver the energy savings performance projected from the prototype tests; the cost premium must be modest (preferably < ~20%) or offset with a utility incentive program, and maintenance issues must be properly addressed. If these issues are successfully addressed, the HyPak has a strong likelihood of success.

4.2.5. Competing Companies Dozens of HVAC manufacturing companies produce equipment targeting the RTU market. Approximately one-third of the domestic HVAC market is served by the four largest producers, as follows7: Company Market Share Carrier (United Technologies) 15% Lennox International 8% Trane (American Standard) 7% York International 4%

These Fortune 500 companies have dominated domestic and export HVAC markets throughout recent history. They are listed below in order of 2002 HVAC sales descending from $8.9 to $3.1 billion, Carrier to Lennox, left to right, in Table 4-7, and illustrated in Figure 4-1.


Table 4-7: Largest HVAC Companies

1 2 3 4 Carrier Trane

Top Competitors by (United (American York market share (l to r) Technologies) Standard) Intern'l Lennox

Annual Sales HVAC ($mil) 8,895.0 4,692.0 3,930.7 3,119.7

Notes: (1) United Technologies, parent of Carrier, reported $28.2 billion total 2002 sales. (2) American Standard, parent of Trane, reported $7.4 billion 2002 sales including plumbing and automotive products.

Source: HOOVER'S ONLINE (www.hoovers.com), January 2003

-

2,000.0

4,000.0

6,000.0

8,000.0

10,000.0

Annual Sales HVAC ($mil)

Carrier Trane York Lennox

Figure 4-1: Top HVAC Market Competitors by 2002 Market Share

The next tier of manufacturers are small relative to the total market, with company-wide sales of $100 to $200 million dollars. For example, Aaon, Inc., with 2001 sales of $157 million has enjoyed significant growth in recent years with a reputation for high production quality, and value added options, Aaon targets big box chain retailers and schools, and is typical of most smaller companies. International Comfort Products, dba: Heil, Arcoaire, and Comfortmaker (“Tempstar” brand) is similarly positioned in niche markets with recent sales volume ranging from $150 to $200 million.

4.2.6. Competing Products In the current market, there is little to differentiate one RTU product from any other. They share comparable internal components and cabinetry with minor design variations. They tend to be nearly indistinguishable in the field, down to overall dimensions and weights. The same is true of the relative equipment cost and benefits, in terms of energy efficiency and operating costs, from any one product to any comparable one.


In a 1998 report8 the American Council for an Energy-Efficient Economy (ACEEE), found that RTU’s were used in over 50 percent of U.S. commercial buildings because of low first cost, simple design, and roof mount capability. They were described as “a commodity item, often costing less than $500/ton, resulting in many design compromises including small coils, constricted air paths, low efficiency compressors and fans, and leaky ductwork.” Most RTU’s are not simply air conditioners. They also deliver forced-air heating using either a reversible refrigerant system (heat pump) or, more typically in most of the U.S., a gas furnace section. A Benefit/Cost comparison of conventional RTU’s versus HyPak is shown in Table 4-8. Conventional unit costs (equipment only) were obtained through industry sources listed below the Table and from specific reference documents provided in the bibliography. HyPak costs were assumed at mature market levels, with high volume. On the benefits side, this comparison considers only energy efficiency (EER) and corresponding energy cost reductions. HyPak also delivers other benefits that are more subjectively valued. These include increased ventilation, longer equipment life, and superior comfort. The comparison shows a positive Benefit/Cost Ratio of 1.38 for HyPak compared to the conventional high efficiency case.

Table 4-8: Benefit/Cost (BCR) Comparison

Conventional RTU’s

Standard High % Inc % Inc

Efficiency BCR HyPak BCR

Cost/Ton $425 $506 $800 10-Ton Unit Cost

$4,250 $5,060 19.1% $8,000 58.1%

Efficiency (EER)

9.7 11.0 13.4% 19.8 80.0%

Benefit/Cost Ratio

0.70 1.38

Sources: 1. "…. RTU product prices range from $300 to $550" (LexisNexus™ Academic, January 21,2003). 2. Standard Efficiency: Trane Model YC*180B3,B4,BWL/BWH General Data (RT-PRC001-EN) 3. Consortium for Energy Efficiency: High-Efficiency Commercial Air Conditioning and Heat Pumps Initiative (HECAC), Efficiency Levels, Effective July 1, 2002; Per-Unit Incremental Costs and Savings of High-Efficiency Packaged Commercial A/C

Comparison costs and efficiencies are illustrated in Figures 4-2 and 4-3.


HyPak Cost Comparison

$0

$200

$400

$600

$800

$1,000

Cost/Ton

Standard High Efficiency HyPak

Figure 4-2: HyPak Cost Comparison

HyPak EER Comparison

0

5

10

15

20

25

Efficiency (EER)

Standard High Efficiency HyPak

Figure 4-3: HyPak EER Comparison

Illustrated in Figure 4-4 below are the Air Conditioning Research Institute (ARI) Energy Efficiency Ratings (EER’s) for five major RTU market competitors, compared to HyPak. Additional comparison data are provided in Table 4-9 below. The HyPak rating was achieved in laboratory tests of Prototype 1 under ARI ratings conditions by Des Champs Technologies in 2002. We assumed that a commercial HyPak product would be configured to match these EERs. As the figure shows, HyPak has nearly double the efficiency rating of the five representative “high efficiency” competitors, which include the four largest companies in the industry and an innovative and aggressive smaller company (Aaon).


Energy Efficiency Ratings

0.0 5.0 10.0 15.0 20.0 25.0

1

ARI EER

HyPakYorkLennoxCarrierTraneAaon

Figure 4-4: Energy Efficiency Ratings

Table 4-9: Comparative Efficiency Levels

Manufacturer Model Capacity (Mbtu/h) EER HyPak Prototype 1 120 19.8 Aaon RK-10-2,3-G*-000:*A 128 11.0 Trane THC120A3*0A**000000000000 108 10.7 Carrier 50HJ-012---(5,6)5 120 11.0 Lennox LCA120H* 120 11.0

York DH120C,E***2***** 115 11.0

4.2.7. Market Share What is the market share potential for HyPak? Examples of previous innovative HVAC technology introductions may be instructive. The scroll compressor was introduced by Copeland in the mid 1980’s. Trane and Carrier introduced their versions a few years later, and now scroll compressors hold over 50% market share. Similarly, screw chillers were introduced in the mid-1980’s. Prior to that, large chillers were centrifugal and smaller chillers were reciprocating. Market share for screw chillers continues to grow and is now approaching 50%. DEG believes that HyPak can replicate these successes by capturing 20% of the RTU market within ten years of introduction. To achieve this market penetration, sub-licensing arrangements may ultimately be required with additional manufacturers. This projection is consistent with a study completed by Arthur D. Little in January 1995 for the DOE's Office of Building Technologies. In that study, an ADL graph projects that technologies with a two year payback achieve 7% market share within five years and an ultimate adoption rate of 30%, ten to twenty years after introduction. HyPak’s payback is anticipated to be under two years. On this basis, a 20% HyPak market share within ten years appears reasonable.


4.2.8. Market Size HyPak will compete with other RTU products designed for rapid, low-cost installation on predominantly low-rise commercial and institutional buildings. Low rise building design is preferred for housing many commercial activities including small and large retail, fast food and restaurant, office and professional, schools and others. Initially HyPak will be marketed in the West. Table 4-10 presents building population and floorspace data for the eleven western states and the total US. From 1992 through 1999 in the West, the building population grew from 825,000 to 1,020,000, or an average of 2.5% per year. Total floorspace kept pace at 2.4% per year average growth, finishing 1999 with an inventory of 14.7 billion ft2. Nearly 53% of the floorspace (43% of the buildings) were equipped with packaged HVAC equipment (RTU’s), and over 87% of the buildings were less than 25,000 ft2, the building size range most likely to specify equipment sizing within the intended HyPak size range (10- to 30-tons). Using1999 data as the base for projecting HyPak annual market size and stable growth rates, HyPak target market (new construction) growth in the west will trend up from 10,900 buildings averaging 16,900 ft2 each or 185.5 million ft2 per year (Calculation). The national market size is more than triple the number of buildings and more than four times the floorspace.

Table 4-10: West/US Number of Commercial Buildings and Floorspace

West Census Region

1999 1999 Pkg Growth Growth/Yr 1999 Pkg AC AC - % Avg/Yr 1999 Base

Total Number of Buildings (1,000) 1,021 443 43.4% 2.5% 10.9 (avg 16,900 ft2) Less than 25K ft2 891 87.3% Total Floorspace (million ft2) 14,731 7,773 52.8% 2.4% 185.9 (million ft2)

National Census Region

1999 1999 Pkg Growth Growth/Yr 1999 Pkg AC AC - % Avg/Yr 1999 Base

Total Number of Buildings (1,000) 4,657 1,953 41.9% 1.7% 33.8 (avg 24,150 ft2) Less than 25K ft2 4,166 89.5% Total Floorspace (million ft2) 67,338 36,527 54.2% 2.2% 816.3 (million ft2)

Sources: USDOE: Energy Information Administration, Office of Energy Markets and End Use, 1999 Commercial Buildings Energy

Consumption Survey: Building Characteristics Tables; 1992 Commercial Buildings Characteristics -- Executive Summary


An estimate of the corresponding base year dollar value of the western RTU market can be obtained by dividing the base year floorspace by 400 ft10 to derive the approximate total tons and multiplying the result by $42511, per ton average cost, which rounds off to $197 million12 in the western new construction market, alone. Sales for retrofit and in other regions multiply the potential market by a factor of 10 or more, to over $2 billion per year. Conclusion: HyPak is Commercially Viable Based on the analyses above, it appears that Hypak products are commercially viable and have the potential to achieve $400 million in annual sales within 10 years of introduction.

4.3. Steps Necessary to Develop Technology into a Marketable Product

4.3.1. Technical Hurdles The main technical hurdles to overcome in commercializing HyPak are to ensure that the product has a high EER, preferably in the high teens or low 20s, and to ensure that it operates reliably. To accomplish this, the various design features developed and tested as part of the HyPak Project will be reviewed for reliability. Only those that the design team has utmost confidence in would be included in an initial product. Likewise, the product would be designed to achieve its EER goals. Fortunately, many of the features developed in the HyPak Project are deemed to be highly reliable. For example, the CEWC developed and tested in Phase 3 performed admirably. Other features that would be included are the DX coil, the direct drive supply blower, an ECM motor for the supply blower, a single speed motor on the tower exhaust fan, the high efficiency air filter (likely as an option) and the hydronic heating coil. Although the CEWC has performed well, it is not yet easily or inexpensively manufacturable. Further research is needed to improve manufacturability. Therefore, a simpler, existing indirect heat exchanger would be used in the initial product. The capability to pre-cool ventilation air and also cool water for the water cooled condenser is a proven, key feature and would be included in an initial product. A necessary step to commercialize HyPak would be the design of units in multiple sizes. Typical installations require units of varying sizes, and this market requirement must be met. Once the designs are completed, tooling must be procured so that production can begin.

4.3.2. Performance Verification To verify performance, one or more prototypes would be fabricated as part of the design process. A prototype would be tested in the lab, design refinements made if needed, and


production could then commence. The next step would be to beta test a significant number of units in the field to monitor reliability, maintainability and overall performance. Assistance from public agencies or utilities would be sought for the beta tests. Once the beta tests were complete, production, promotion, marketing and sales would be ramped up. Discussions are now underway with an interested and capable manufacturer to accomplish all of this.

4.3.3. Future Recommended R&D Much was learned as a result of the HyPak Project. There is a strong likelihood that Des Champs Technologies will commercialize a high efficiency, evaporatively-cooled RTU based on our work under the NETL grant. The initial HyPak version will likely deliver 100% ventilation air. This “most simple” HyPak will fill a market niche and take full advantage of the benefits of an indirect evaporative heat exchanger that pre-cools ventilation air while also efficiently cooling the condenser. To take full advantage of the progress made in this project toward perfecting a “mixed air” HyPak version, we recommend further development of an advanced design whose schematic cross-sectional view is shown in Appendix K. This improved design has the following features and characteristics:

• Horizontal above-roof unit to facilitate service • Includes two relatively-matched blowers, both with ECM’s • Uses two tall narrow CEWC’s spaced apart, facilitating a lower profile • Locates condenser CEWC over cantilevered reservoir • Vent air CEWC pan drains to condenser-side reservoir • Pump feeds both CEWC’s in parallel • Uses counterflow condenser with multi-spiral internal heat exchanger • Places first filter on ventilation air, second on return air • Only return air crosses the evaporator and heating coils • Two 3-position dampers provide full-open economizer cycle

The major benefits of this refined design compared to the Phase 3 HyPak designs include:

• Lower profile, comparable to conventional RTU’s • Provides “full-open, straight-through” economizer flow without coil pressure

drops, a significant advance over conventional RTU’s • Ventilation air is fully separated from the water reservoir • Coil sizes and costs are reduced, as only return air passes over the coils • With the compressor off, condenser side water helps cool ventilation air • With cooling on and ventilation air off, vent side water helps cool the condenser • The design would use an advanced plastic plate approach developed in DEG’s

indirect/direct evaporative cooler (IDEC) project. The IDEC plate technology includes integral water feed troughs that require less space and improve water containment compared to a spray system.


We strongly recommend additional funding to develop this more compact and more marketable “mixed-air” HyPak version, which we believe can achieve a 20 EER ARI rating, with even higher performance under Western conditions. This work would further refine the counterflow evaporative water cooler (CEWC) begun in this project. The CEWC has very effectively pre-cooled ventilation air while also providing cool water to improve efficiency by reducing condensing temperatures. We fabricated the initial prototype from paper with a laminated plastic sheet backing, and then developed a thermoforming process to make plastic CEWC plates. Additional effort is warranted to optimize the plastic plate design for both indirect heat exchanger types shown in the HyPak design recommended above.


5. Conclusions and Recommendations

Based on the work completed in this project to develop the HyPak, a hydronic packaged rooftop unit, we offer the following conclusions:

• Our review of conventional rooftop units (RTU’s) in comparison with our test results indicates there is a significant opportunity to improve the efficiency of widely-used “mid-sized” (10-30 ton) packaged cooling/heating/ventilation units, particularly regarding cooling and ventilation performance. In cooling mode, the best available units deliver only 12 Btus/watt, while our results indicate that 18-20 Btus/watt can be cost-effectively delivered with an improved unit.

• The major opportunity for improving cooling performance applies evaporative cooling to both the condensing function of the refrigeration cycle and to ventilation air. While this evaporative cooling strategy significantly reduces annual energy consumption, it is even more effective at reducing peak cooling demand, since evaporative benefits are greatest at high outdoor temperatures.

• Adding the evaporative cooling feature requires that water be used in the cooling cycle. Most HVAC manufacturers are reluctant to introduce evaporative cooling to these relatively small rooftop units because of maintenance concerns. Minimizing maintenance costs and demonstrating a substantial reduction in energy costs are essential to success for a new evaporatively-based rooftop unit.

• Based on input received from focus groups conducted in this project, industry participants would expect commercial success for a hydronic rooftop unit that can achieve 18 Btus/watt performance in western summer conditions, and improves air quality with filters that require less frequent replacement. However, initial and maintenance costs must result in favorable economics to assure market success.

• The counterflow evaporative water cooler (CEWC) first reduced to practice in this project is important to the design of an efficient, compact hydronic RTU. This project has demonstrated a CEWC that can cool condenser inlet water to within 5°F of the wet bulb temperature while at the same time pre-cooling 105°F outdoor air to approximately 80°F when the wet bulb temperature is 70°F.

• A hand-made paper/plastic laminated CEWC performed well in Phase 1 and 2 project tests, and we fabricated two advanced thermoformed plastic CEWC’s in Phase 3. Plastic plate materials and production processes recently developed in another Davis Energy Group R&D project suggest substantial further improvements in CEWC economics for HyPak.

• We made considerable progress in all three phases of this project, by proving the potential of the CEWC in Phase 1, designing, building, and testing a first working prototype in Phase 2, and fabricating two redesigned field-worthy units in Phase 3. One of the two was installed at a field test site and is equipped for ongoing monitoring.

• Neither prototype designed, fabricated, and tested in this project has clearly achieved 18 Btus/watt, and the field test unit has not operated for a sufficient time period to verify that maintenance costs will be acceptably low. However, calculations based on a combination of test results and known engineering parameters indicate that a further-improved design


can achieve 18 Btus/watt, while providing other clear advantages over today’s RTU’s. Further R&D is needed to verify this potential.

• The HyPak configuration will be crucial to product success, both with respect to size and air flow patterns. This project evaluated many possible configurations, beginning with a “through-the-roof” design that would minimize visual impact and improve efficiency by locating the supply air components below the roof, thus providing a “straight-through” return air path and limiting rooftop exposure. However, after building a mockup of the initial design in Phase 1 we concluded, with manufacturer and industry input, that maintenance issues limited the immediate potential of the “through-the-roof” configuration.

• The initial airflow configuration used in both the “through-the-roof” design and our two subsequent above-roof designs have two liabilities that can be overcome with an improved configuration. The first liability is that a limited volume of ventilation air can be delivered to the occupied space; thus a standard “economizer” mode cannot be provided. The second liability is the proximity of reservoir water to the ventilation air stream, generating fears that in some pressure conditions contaminants might be drawn into the ventilation air.

• A revised configuration based on project experience eliminates these liabilities and would provide superior economizer performance by opening “straight-through” inlet and exhaust air paths that bypass the cooling and heating coils. The revised configuration provides two smaller CEWC components that share duties but always maintain separation between the reservoir and ventilation air. The CEWC’s would use revised air and water inlet patterns that facilitate a lower profile and smaller cabinet compared to the previous prototypes. Based on project results we project that a next prototype can cost-effectively surpass 18 Btu/watt-hr cooling efficiency in typical Western operating conditions and may approach 20 Btu/watt-hr.

Based on these conclusions, we strongly recommend funding support for the following continuing activities:

• Design, fabrication, and lab testing of a third prototype configured as summarized

above and more fully described in Section 4 of this report. • Development of the advanced CEWC design with side air entry/exit paths and low

profile water feed system. • Based on successful completion of the design/development tasks, implementation of a

field test program that places at least three units of the refined design in a range of U.S. climates.

March 25, 2004 DE-FC26-00NT40991 – HyPak Final Report Page A-1

Appendix A: Phase 1 Component Selection


A.1. CEWC As described in Sections A.1.3.2 and A.1.5, our selected CEWC design uses flat evaporative media laminated to a plastic laminate. We used corrugated plastic spacers to maintain passage widths.

A.1.1. CEWC Dimensions The selected plates are 27” wide and 30” tall. The plate spacings are 6 mm in the dry and 8 mm in the wet. Figure A-17 shows a cross-section of the wet and dry passages.

A.1.2. CEWC Fan Test results from the full width CEWC prototype indicated an air pressure drop of 142 Pa (0.57” WC at 885 cfm) across the CEWC. With improvements to smooth the entry to the dry passages, we expect to lower the pressure drop to about 125 pa for 7100 L/s (2500 cfm) for a 35 kW (10 ton) CEWC. To satisfy these requirements, we selected the Airfoil Impeller 1801 U2-2418-4-18 REG Panel Fan. See Appendix C for a fan curve. This fan requires 310 W (0.42 hp) of power to deliver 71,000 L/s (2500 cfm) at the stated pressure drop.

A.2. Air Handler

A.2.1. Aircoil The HyPak design uses a hydronic air coil to deliver both heating and cooling. The specified air coil is designed for excellent counterflow performance and low pressure drop. The 8 row coil has 8 fins per inch spacing and overall dimension of 48”x 30”. The 10 ft2 face area results in 300 fpm velocity of at 3000 cfm

A.2.2. Air Filter Indoor air quality (IAQ) is a key area for improvement compared to conventional RTUs. In Phase 1, Lawrence Berkeley National Laboratory’s Indoor Environment Department set filtration goals and developed a spreadsheet tool as an aide for filter selection. LBNL/IED participated in the design of the outside airflow section and developed a CONTAM model allowing investigation of HyPak/Building interactions. IAQ and HyPak project objectives One of the HyPak project’s broad design goals has been to enhance indoor air quality by improving air filtration and controlling ventilation airflow rate. The intended market for the HyPak unit is the same as single package rooftop units. This market is extremely sensitive to first costs. A typical 10-ton (35kW) package rooftop unit comes new with 1” or 2” thick low efficiency panel filters (often called furnace filters). The filter cost to the equipment manufacturer is less than a dollar and the pressure drop is small. The current emphasis on very low filter cost and pressure drop imposes a challenge in providing filters that meet IAQ goals with a reasonable service life and a minimum pressure drop.


Filtration Background Filter efficiencies are a function of the particle size. For particles >0.3µm, the larger the particle the greater the filter efficiency. The filter efficiency starts to level off above 5µm, and for these relatively large particles most filters have a moderate to high efficiency. As particle sizes drop below approximately 2µm, filter efficiencies may decrease rapidly, and these are the size of particles that most affect human health. There are two basic efficiencies commonly associated with filters — arrestance (gravimetric), and dust-spot. Arrestance refers to the amount of dust “caught” by the filter. ASHRAE Standard 52.1 refers to the arrestance (defined as grams of dust left on the filter/grams of dust fed to the filter) of a particular test dust and arrestance efficiencies range from <65% to essentially 100%. The dust used to measure arrestance and dust holding capacity (DHC) is composed of large diameter particles. The second commonly used filter efficiency is dust-spot efficiency. Dust spot efficiencies are intended to determine how well a filter cleans the air to prevent soiling of surfaces. Dust spot efficiencies range from <20% to 99+% for the most efficient filters. Arrestance results are useful indicators for DHC and the efficiency of removing larger particles, while the dust spot efficiency characterizes overall filter efficiency with smaller particles. ASHRAE has a new Standard 52.2, which quantifies filter efficiency in several particle size ranges. The reporting ranges are 0.3-1µm, 1-3µm, and 3-10µm. Results are expressed as a MERV –minimum efficiency reporting value—rating. MERV values range from 1 to 16, the higher the number the more efficient the filter. This standard was adopted in 1999 and not all filters have a MERV rating. Filter manufacturers rarely provide adequate information to select filters based on life cycle costs. Typical data contained in “engineering product literature” include available filter sizes, initial (clean filter) pressure drop at a design velocity, and the final pressure drop. Sometimes these data include additional initial pressure drops at other velocities, the filter efficiency (dust spot or MERV), and the media area of the filter. A key piece of information often missing is the dust holding capacity (DHC) of the filter. The DHC is a measure of the test dust quantity a filter holds when it reaches its final pressure drop. DHC is typically expressed in grams of test dust for a particular filter size and is one of the tests in ASHRAE Standard 52.1. Manufacturers, through technical sales representatives, will provide DHC data for specific products requested if it is available. Filter Efficiency Target for HyPak Figure 3-37 shows the reduction in indoor particle concentrations using various filter options. The figure is from a paper submitted to Indoor Air (Fisk et al. 2001)1. The figure indicates that filters with dust spot efficiencies in the 60-65% range are effective in reducing indoor concentrations of particles from various sources, and that only modest benefits result from increasing the efficiency. Consequently a dust spot efficiency of 60-65% (MERV rating 10 or 11) became the filtration design goal for HyPak. The 1” furnace filters typically used in package units have dust spot efficiencies less than 20%

1 Fisk W.J., Faulkner D., Seppanen O., Palonen J. “Performance and Cost of Air Filtration” Submitted to Indoor Air, 2001


and MERV’s of 1 to 4. The newer “high quality” pleated panel filters becoming available to the residential market have dust spot numbers in the 25% range and MERV’s of 6 to 8.

Figure A-37: Predicted Reduction In Indoor Particle Concentrations Using Various Filters

Furnace filters have dust spot efficiencies <20%. ASHRAE30 refers to a filter with a dust spot efficiency of 30%. Pocket filters have dust spot efficiencies >95%, and dust spot efficiencies of HEPA filters approach 100%. Cat allergen and dust mites represent larger particles (>3µm and the two distributions represent different data sets). ETS (environmental tobacco smoke) and outdoor fines represent smaller particles (<3µm). Filter Selection Methodology Since DHC was not readily available for all products it was estimated from data on hand. The basic assumption was that filters with similar media area have a similar DHC over a working range of pressure drop (final – initial pressure drop).

HVAC Supply Filter1 ACH OA Supply, 4 ACH Recirculation

0.25 ACH Infiltration

0% 20% 40% 60% 80% 100%

Furnace

ASHRAE30

ASHRAE45

ASHRAE65

ASHRAE85

ASHRAE95

Pocket

Hepa

Cat Allergen % Reduction

Custovic Size Dist.

de Bley Size Dist.



0% 20% 40% 60% 80% 100%

Furnace

ASHRAE30

ASHRAE45

ASHRAE65

ASHRAE85

ASHRAE95

Pocket

Hepa

Dust Mite % Reduction

Tsubata Size Dist.

Tovey Size Dist.



0% 20% 40% 60% 80% 100%

Furnace

ASHRAE30

ASHRAE45

ASHRAE65

ASHRAE85

ASHRAE95

Pocket

Hepa

ETS % Reduction

HVAC Supply Filter1 ACH OA Supply

0% 20% 40% 60% 80% 100%

Furnace

ASHRAE30

ASHRAE45

ASHRAE65

ASHRAE85

ASHRAE95

Pocket

Hepa

Outdoor Fine Mode % Reduction

No Inf iltration4 ACH Recirculation

0.25 ACH InfiltrationNo recirculation

4 ACH Recirculation, 0.25 ACH Infiltration


Since fan power is a linear function with pressure drop, a major project design objective was to minimize overall pressure drop. The high efficiency filters have a final pressure drop of 1.5 in.wg. The design team felt that from an energy perspective, this is unacceptable. A possible solution is to change out the filters before they reach the manufacturer’s final pressure drop. This in essence changes out filters prematurely; the trade off is between energy costs and filter costs. All maintenance on the HyPak unit is to take place from the roof. This includes filter changes. Due to access issues and space limitations the maximum filter depth was decided to be six inches. Filter Selection Spreadsheet Tool A spreadsheet was constructed to investigate life-cycle costs. The general input values are operating hours, occupant density, indoor/outdoor particle mass concentrations, flow rate, filter size, fan/motor efficiencies, and electrical costs. Specific filter inputs are filter media area, initial pressure drop (and corresponding flow rate), filter cost, and arrestance. The spreadsheet calculates an adjusted initial pressure drop based on the actual velocity. With the desired final pressure drop the spreadsheet calculates the DHC and the life span for the filter. It is assumed that the pressure drop increases linearly with dust collected on the filter. This assumption implies the average fan power will be proportional to the average pressure drop across the filter. The primary spreadsheet outputs are: weeks of useful filter life, average weekly energy costs, weekly filter costs, and average combined (energy and filter) per person costs. Filter life span ranges from a few weeks to a few years. Filter costs range from a few dollars to more than $100. Weekly per person costs are in the range of $0.15 to $0.20. HyPak Filter Recommendations At this time the Koch Multi-Flow series of filters (either series G or S in a 6” depth 65% dust spot efficiency, with an initial pressure drop of 0.3inwg and a lifespan to 1inwg of 52 weeks) are the leading contenders. The estimated monthly cost per 1000cfm and per person are approximately $2.73 and $0.69 respectively. This selection is based on an assumed DHC. Final selection should take into account additional information on DHC from this and other manufacturers.

A.2.3. Ventilation Air Fan

Ventilation Background and HyPak Goals Ventilation, in the form of outside air, in a conventional RTU is usually introduced via a minimum position setting of an economizer, or through an opening on the side of the unit with or without a manually adjusted damper. Economizers are notoriously unreliable; dampers often stick or are manually disconnected. Passive openings on the sides of units are just that—passive, with the flow rate set once and forgotten. With either economizers or openings, determining the outside airflow rate in the field is extremely difficult. With conventional units the end result is that indoor spaces often receive highly variable outside air. Receiving too little outside air is detrimental to IAQ, while too much imposes an energy penalty.


The HyPak ventilation goal is simply to provide a controlled, and known, amount of outside air at all times. HyPak/CEWC CONTAM Model LBNL was concerned about possible interactions of the building and the HyPak unit. Specifically the HyPak unit will not have any control of how tight or leaky the building shell is, or the size and make up of exhaust systems in the building. The combination of building shell leakage and improperly set exhaust systems has the potential of preventing HyPak from meeting its intended goals. LBNL created a multi-zone model to study these building/HyPak interactions. The model was a six-zone CONTAM model and was limited to the CEWC section and the building. Input parameters to the CONTAM model are: CEWC dry and wet side airflow resistances, exhaust return path (return from building to the CEWC) airflow resistance, building shell effective leakage area, building exhaust (independent of HyPak) airflow rate, and fan characteristics (CEWC and ventilation). HyPak Ventilation layout Ventilation air in the HyPak unit comes from the bottom of the dry passages of the CEWC section. Since the air is drawn through the passages by the CEWC fan, the bottom of the unit is at a negative pressure with respect to outdoors. This means the ventilation air has to be moved from a negative pressure region. The initial concept had the ventilation air connected to the main HyPak return air with an integrated system of sensors and controls for outside air measurement and control. Some degree of pressure drop is required in order to control and accurately measure airflow rates. This further decreases the pressure of the ventilation air stream. For the initial design to work, the pressure where the ventilation air is provided to the HyPak unit (somewhere in the return-air path) must be lower than the pressure downstream of the measurement and control devices. To achieve this would require adding a pressure drop to HyPak’s return-air path. The added pressure drop would apply to the entire HyPak air stream and would impose a significant energy penalty. During Phase 1 of the project, the project team developed the concept of installing an independent ventilation fan between the bottom of the CEWC and the HyPak return. This fan eliminates the need for an artificial pressure drop in the HyPak return path. The fan will be a multi-speed unit allowing discrete changes in the ventilation airflow rates. The CONTAM model indicates the ventilation fan concept is viable. However, there is a possibility of having an imbalance in the CEWC flows. An imbalance is defined as a difference in airflow between the dry and wet sides. It appears this imbalance can be minimized/eliminated with careful design of the exhaust return path. One possible solution is a damper in the exhaust path that closes when the ventilation fan operates at low settings. HyPak Ventilation Verification Adding an outside air ventilation fan to HyPak simplifies the task of ventilation measurement. The fan should eliminate, or simplify, the need for active sensor based


measurement. Ventilation flow rate will be inferred from the fan speed, possibly supplemented with a pressure sensor. This form of measurement will be possible if the system can be carefully characterized. Obviously the characterization must occur after full-scale prototypes are constructed. Phase II work will focus on design, specifications, and protocols for characterizing the ventilation flow rate at each fan speed setting. In Phase III we will perform experiments to fully characterize outside air ventilation flow rate at each fan speed.

A.2.4. Supply Blower We first developed alternate system pressure profiles to help establish acceptable external system static pressures. Agreement on these profiles and 0.70” acceptable external static pressure helped identify our overall supply blower at 325 PA (1.3” WC). DLI recommended a plug fan by New York Blower for this application. We selected the NYB 18” AcoustiFoil blower wheel. The 18” Acme STARS (Single Thickness Airfoil Reduced Sound) wheel, developed in conjunction with ADL, is a lower cost alternative. The mounting structure for the blower wheel will be incorporated into the sheet metal enclosure

A.2.5. Ventilation Blower The ventilation blower is necessary to overcome the negative pressure drop between the bottom of the CEWC dry passages and the building return duct connection. The blower had to fit into a narrow compartment next to the CEWC. Air curtains had a suitable shape, and the Dayton Electric 4YP01 Air Curtain was selected.

A.2.6. Biological Treatment Although ventilation air is indirectly evaporatively pre-cooled by the CEWC, the ventilation air physically approaches the CEWC sump. The controls will drain the sump every 24 hours to prevent biological growth. As an additional safeguard to maintain indoor air quality, we have specified the Lennox Healthy Climate Germicidal UV Light Model UV-XXX as an optional feature to sterilize supply air and neutralize odors.

A.3. Refrigeration system As described in Section 3.2, the HyPak refrigeration system was selected to deliver sensible cooling quantity to the building space identical to that from a typical 35 kW (10 ton) RTU. To provide this cooling with a minimum of compressor power consumed, we refined the system to maximize EER (a ratio of cooling delivered to power consumed). The EER of a compressor increases as the condensing temperature decreases and the evaporator temperature increases. The team decided to develop a system based on R-410a refrigerant. R-22 will be phased out in new equipment in the US in 2010, per the Clean Air Act and Montreal Protocol. In Europe, R-22 has been phased out of most equipment and Japan will accomplish this in the next three or four years.


There are 2 major alternatives to R-22: R-407c and R-410a. It appears to be a general consensus in the industry that R-410a is the long term preferred option. R-407c is an easier transition because it operates at similar pressures as R-22, so the engineering required for conversion of an R-22 design to R-407c is small. However, there is a substantial performance degradation when moving from R-22 to R-407c (~7-10% efficiency drop). In contrast, going to R-410a can give you an efficiency boost (~0-5%) relative to R-22, but requires substantial redesign to accommodate the higher pressures of R-410a. Although Carrier initially offered R-407c products, it has now moved to R-410a, they and Copeland are now pushing for R-410a to become the industry standard. The various industry studies conducted by ADL indicate that almost everyone in the US (with a few exceptions) believes R-410a is the long term alternative to R-22. Although most major HVAC equipment suppliers are still selling a majority of R-22 products, most have begun to offer R-410a products. By the time HyPak reaches the market, it would only have a realistic life of a few years before R-22 was phased out completely in new equipment.

A.3.1. Condenser A larger condenser heat exchanger decreased the condensing temperature but with a substantial cost penalty. For Phase 1, we selected the FlatPlate C15B 5.0” x 20.3” x 6.0” condenser.

A.3.2. Evaporator A larger evaporator heat exchanger increased the evaporating temperature but with a substantial cost penalty. For Phase 1, we selected the FlatPlate CH15B 5.0” x 20.3” x 6.9” evaporator.

A.3.3. Compressor The team chose to use scroll compressor technology to maximize efficiency. We selected the Copeland ZP54K3E. The nominal capacity of this compressor is only 15.9 kW (4.1 ton), but the performance improvements of the HyPak system allow this compressor to satisfy the same building envelop load as a 35 kW (10 ton) compressor in a conventional RTU. The increased capacity and efficiency of the operating this compressor at HyPak conditions versus standard air conditioning conditions is shown in Table 3-3.

Table A-3: Copeland ZP54K3E Performance

Operating Condition Standard AC HyPak Change Condensing Temp 54°C (130°F) 33°C (91°F) 21°C (39°F) Evaporating Temp 7°C (45°F) 9°C (48°F) 2°C (3°F) Compressor Capacity 15.9 kW (54,400 Btu) 22.2 kW (75,900 Btu) +40% Power Consumption 5230 W 3140 W -40% EER 10.4 24.1 +132% Heat Rejection 21.2 kW (72,300 Btu) 25.4 kW (86,600 Btu) +20%

A.3.4. Thermostatic Expansion Valve The thermostatic expansion valve (TXV) selected by the team is the Danfoss TCBE.


A.4. Water loops 1-1/4” copper type L tubing was selected for the water loops. This size provided a good compromise between low pressure drop and cost, for both the tubing itself and the other components of the water loops.

A.4.1. Pumps The Taco 0011 pump was specified for both water loops. It consumes 93 W (0.125 hp) of power. This pump provides the flow rates specified in Table 3-4.

Table A-4: Water Loop Flow Rates

Circuit Flow Rate Single Loop 0.725 L/s (11.5 gpm) Split Loop – Condenser Loop 1.136 L/s (18.0 gpm) Split Loop – Evaporator Loop 0.883 L/s (14.0 gpm) Heating Loop 0.789 L/s (12.5 gpm)

A.4.2. Valves The HyPak system required two motorized 3-way valves to switch between single and split loop cooling modes, and to switch from cooling to heating modes. The Honeywell 1” VC 3-way Balanced Hydronic Valve was selected.

A.4.3. Check Valves Two check valves are required to separate the two loops during split mode operation. We selected the Nibco 1” S-413-W with butyl seal was selected.

A.4.4. Water Heater We selected the Munchkin 140M Stainless Steel Water Heater produced by Heat Transfer Products. This unit modulates gas consumption to match the load demanded, reducing cycling. It has a capacity of 41 kW (140,000 Btu) and operates at efficiencies of 95-97%.

A.4.5. Piping We specified 1 ¼” copper type L tubing for the water loops

A.4.6. Water Treatment Evaporative coolers installed in hard water areas suffer from mineral build-up. The HyPak controls will drain the CEWC sump at regular intervals to keep mineral concentrations low. Mineral scale can increase pressure drop and impede heat transfer. To further reduce scaling, HyPak will offer the Fre-Flo scale prevention system as an optional feature. Fre-flo uses a catalyst to keep minerals in suspension until the water loop is drained at regular purge cycles. The device operates without use of chemicals, magnets, softening or electricity, and never needs replacement.


A.5. Other Components

A.5.1. Supply Blower Motor A one horsepower high-efficiency motor will be selected during the detailed design process in Phase 2.

A.5.2. Condensate Pump We selected the Little Giant 1-ABS Condensate Pump to move condensate from the coil pan upward into the evaporative sump.

March 25, 2004 DE-FC26-00NT40991 – HyPak – Final Report Page F-1

Appendix F: Laboratory Test Plan


Laboratory Test Plan for HyPak Phase 3 Prototype

Task 3.2: Fabricate and Test Refined Prototype

F-1. Objective

To evaluate the performance and operating behavior of the HyPak prototype under a variety of operating conditions. A laboratory capable of simulating a wide range of conditions will be employed. Testing will characterize system performance and operation and allow the team to better predict the performance of the production version of HyPak.

F-2. Standards The test conditions follow those of the Air-Conditioning and Refrigeration Institute (ARI) Standard 340/360 (2000): Commercial and Industrial Unitary Air-Conditioning and Heat Pump Equipment. (In addition to the conditions listed by ARI, we have added two test runs more typical of Western summer conditions to evaluate HyPak in its target market.) ARI 340/360 describes the test conditions and parameters, but refers to ASHRAE Standard 37-1998: Methods of Testing for Rating Unitary Air-Conditioning and Heat Pump Equipment for the details of test setup and instrumentation. The team expects to meet all of the requirements of ASHRAE 37 with the exception of temperature measurement, which requires +/-0.2 °F accuracy for both dry-bulb and wet-bulb readings. (We should attain +/-0.4 °F and +/-0.5 °F, respectively.) Temperature measurement is not explicitly described in ASHRAE 37, but is referred to ASHRAE Standard 41.1-1986: Standard Methods for Temperature Measurement. Flow measurement is described in some detail in ASHRAE 37, with more information contained in ASHRAE Standard 51-1999: Laboratory Methods for Testing Fans for Aerodynamic Performance Rating. For flow measurements, the team expects to fully comply with ASHRAE 37 and 51.

F-3. Definitions F-3.1 Cooling Capacity. The total capacity is the sum of the latent and sensible capacities expressed in Btu/hr. F-3.2 Sensible Capacity. Capacity associated with a change in dry-bulb temperature expressed in Btu/hr. F-3.3 Latent Capacity. Capacity associated with a change in humidity ratio expressed in Btu/hr. F-3.4 Latent Fraction. The ratio of latent capacity to cooling capacity. F-3.5 Energy Efficiency Ratio (EER). The ratio of cooling capacity in Btu/hr to the sum of the power input values in watts expressed in Btu/W⋅hr.


F-3.5.1 Standard Energy Efficiency Ratio. The ratio of the capacity to the sum of the power input values obtained at Standard Rating Conditions.

F-3.6 Coefficient of Performance (COP). The ratio of the capacity in watts to the sum of the power input values in watts (dimensionless). F-3.7 Indirect Evaporative Cooling Effectiveness. The ratio of the difference between ventilation air dry-bulb and outdoor air dry-bulb and the difference between outdoor air dry-bulb and outdoor air wet-bulb. F-3.8 Heating Efficiency. The ratio of heating capacity in Btu/hr to the heat content (higher heating value) of the input natural gas in Btu/hr. F-3.9 Heat Recovery Effectiveness. The ratio of the difference between ventilation air dry-bulb and outdoor air dry-bulb and the difference between return air dry-bulb and outdoor air dry-bulb.


F-4. Abbreviations

Abbreviation Description ARI Air-Conditioning and Refrigeration Institute APPWB wet-bulb approach (°F) APT Automated Performance Testing (System) ASHRAE American Society of Heating, Refrigeration and Air-Conditioning Engineers BTU British thermal units CEWC Counter-Flow Evaporative Water Cooler CFM cubic feet per minute CFMGas natural gas input to water heater (SCFM) CFMRA return air flow rate (SCFM) CFMSA supply air flow rate (SCFM) CFMVA ventilation air flow rate (SCFM) COPComp compressor coefficient of performance CpAir specific heat of air (BTU/lb/°F) CpWater specific heat of water (BTU/lb/°F) Cu copper Cu-Ni constantan (copper-nickel alloy) DB dry-bulb temperature (°F) DBEA exhaust air dry-bulb temperature (°F) DBOA outdoor air dry-bulb temperature (°F) DBRA return air dry-bulb temperature (°F) DBRA+VA mixed (or weighted average of) return air and ventilation air dry-bulb (°F) DBSA supply air dry-bulb temperature (°F) DBVA ventilation air dry-bulb temperature (°F) DCT Des Champs Technologies ECM Electronically Commutated Motor EFFHeat heating efficiency EFFHeatRec. heat recovery effectiveness EFFInd.Evap. indirect evaporative effectiveness EERComp compressor energy efficiency ratio EEROverall overall energy efficiency ratio FPM feet per minute GPMAircoil water flow rate through heating aircoil loop GPMCond water flow rate through condenser loop (condenser, CEWC) hRA+VA mixed return air and ventilation air enthalpy hRA return air enthalpy (BTU/lb) hSA supply air enthalpy (BTU/lb) hVA ventilation air enthalpy (BTU/lb) HCM local heat content multiplier, usually 1000 BTU/ft3

HHV higher heating value LBNL Lawrence Berkeley National Laboratory


Abbreviation Description LF overall latent fraction PCEWCE static pressure at CEWC exhaust (before tower fan) (in H2O) PEA static pressure in tower exhaust air duct (in H2O) PIND differential pressure in indoor loop flow nozzle (in H2O) PINS static pressure in indoor loop flow nozzle (in H2O) POA static pressure in outdoor air duct (in H2O) POUTD differential pressure in outdoor loop flow nozzle (in H2O) POUTS static pressure in outdoor loop flow nozzle (in H2O) PRA static pressure in return air duct (in H2O) PSA static pressure in supply air duct (in H2O) PSF differential pressure across supply fan (in H2O) PVFS static pressure in ventilation fan inlet cone (in H2O) PDDry pressure drop across CEWC dry passage (in H2O) PDTotal pressure drop across indoor air loop (in H2O) qVAPC ventilation air pre-cooling capacity (BTU/hr) qcAircoil aircoil cooling capacity (BTU/hr) qcOverall overall cooling capacity (BTU/hr) qh overall heating capacity (BTU/hr) qlAircoil aircoil latent capacity (BTU/hr) qlOverall total latent capacity (BTU/hr) qsAircoil aircoil sensible capacity (BTU/hr) qsOverall overall sensible capacity (BTU/hr) RAT humidity ratio (lb moisture / lb dry air) R/A return air RH relative humidity RHCEWCE CEWC exhaust air relative humidity RHOA supply air relative humidity RHSA supply air relative humidity RHVA supply air relative humidity RTD resistive temperature device ρAir,Aircoil average density of air across aircoil (lb/ft3) ρAir,VAPC average density of air across CEWC dry passage (lb/ft3) ρWater density of water (lb/ft3) S/A supply air SCFM standard cubic feet per minute (at standard conditions) THeatRet water heater return water temperature (°F) THeatSup water heater supply water temperature (°F) TNozzle temperature of indoor loop flow nozzle (°F) TRef temperature of thermocouple isothermal reference junction (°F) TSump temperature of sump water (°F) V/A ventilation air


Abbreviation Description WComp compressor power (Watts) WSF supply fan power(Watts) WTotal total power(Watts) WTF tower fan power(Watts) WVF ventilation fan power(Watts) WB wet-bulb temperature (°F) WBRA wet-bulb temperature of return air (°F) WBSA wet-bulb temperature of supply air (°F)


F-5. Test Conditions F-5.1 Air Temperatures and Ventilation Airflow rates.

Table F-1: Test Conditions

Outdoor Air Return Air Test Dry-Bulb °F Wet-Bulb °F Dry-Bulb °F Wet-Bulb °F

Approx. V/A Rate (SCFM)

1 Standard Rating Conditions1,2 95 75 80 67 0

2 Modified Standard Conditions1 95 75 80 67 800

3 Western Maximum Conditions 100 70 80 67 800

4 Western Summer Conditions 95 66 76 64 800 Coo

ling

5 Low Temperature Operation1 67 57 67 57 800

6 Standard Rating Conditions3 47 NA 70 NA 800

Hea

ting

7 Low Temperature Operation3 17 NA 70 NA 800 1 According to ARI Standard 340/360-2000, Table 3 2 According to ARI Standard 340/360-2000, 6.1.3.2b and 6.1.3.6 3 Taken from ARI Standard 340/360-2000, Table 3 heat pump rating conditions. The unit is not a heat pump, but these conditions are appropriate to evaluate the heating performance of HyPak. F-5.2 Supply Airflow. Supply airflow rate shall be no more than 3000 SCFM. For a typical 10-ton unit, section 6.1.3.2a of ARI 340/360 states that supply airflow should be no more than 4500 SCFM. (37.5 SCFM per 1000 Btu/h) However, it allows for a lower indoor air flow rate if so specified by the manufacturer. F-5.3 Ventilation Airflow. Sections 6.1.3.2b and 6.1.3.6 of ARI 340/360 states that only units equipped with an outdoor aircoil (HyPak does not) test with ventilation air. For that reason, run #1 (Standard Rating Conditions) has 0 SCFM of V/A. However, HyPak will be much more popular in installations with ventilation air requirements, particularly in California where it is required for all buildings. HyPak will a direct replacement for a conventional 10-ton RTU with a typical V/A rate. Therefore, we are attempting to replicate a typical V/A rate for a 10-ton RTU, which according to Section 6.1.3.6 of ARI 340/360 is 20% of the S/A rate. In a typical installation, a 10-ton RTU will have about 4000 SCFM of S/A. For HyPak prototype testing, the V/A rate will be 800 SCFM, or 20% of the supply airflow rate of a 4000 CFM 10-ton unit. If time permits, each run should be repeated with the V/A fan running at maximum power. F-5.4 External Pressure. Minimum external pressure shall be 0.30 inH20.1(Table 4) F-5.5 Make-up Water. Make-up Water shall be 70-75°F.1(Table 3)

F-6. Performance Parameters to be Evaluated F-6.1 General Equations.


F-6.1.1 Enthalpy from wet-bulb temperature (BTU/lb). Enthalpy (h) is calculated using the following approximation based on air temperature and wet-bulb temperature. (Source: ASHRAE Fundamentals)

( )DBRATDBh ×+×+×= 444.09.106024.0 where,

( ) ( )WBDB

WBDBRATWBRAT WS

−×+−×−××−

=∗

444.0109324.0556.01093

and,

∗

∗∗

−×

=WS

WSWS PP

PRAT

62198.0

and,

( )

×+×+×+×++=∗

RRRRR

WS WBCWBCWBCWBCCWBCP lnexp 6

35

2432

1

and, RAT = humidity ratio (lb. of moisture / lb. of dry air)

∗WSRAT = humidity ratio corresponding to WB (lb moisture / lb dry air)

∗WSP = saturation pressure corresponding to WB (Psia)

P = absolute pressure (Psia) WBR = WB + 459.67 C1 = -1.044039708 x 104 C2 = -1.12946496 x 101 C3 = -2.7022355 x 10-2 C4 = 1.289036 x 10-5 C5 = -2.478068 x 10-9 C6 = -6.5459673

F-6.1.2 Enthalpy from relative humidity (BTU/lb). Enthalpy (h) is calculated using the following approximation based on air temperature and relative humidity. (Source: fit to data by DEG)

( )DBRATDBh ×+×+×= 444.09.106024.0 where,

ZZRAT

−×

=26.11013

6219.0

and,

100112.6 YRHZ ××

=

and, 5432 012346.0041667.016393.05.01 XXXXXY ×+×+×+×++=

and,


+

×

−=

14257523467818

.TT

.T

.XC

CC

and,

( )9532 ×−= DBTC

F-6.1.3 Airflow Rate. The throat velocity should be between 3000 and 7000 FPM. Airflow rate through the flow nozzles is calculated as follows: (Source: ASHRAE 37)

NVN vPACCFM ′××××= 1096 where,

( )NN

NN RATP

vv+

×=′

192.29

and, C = nozzle discharge coefficient (0.99) AN = nozzle area (ft2) PV = static differential pressure across nozzle (in. H2O) PN = absolute pressure at nozzle throat (in. Hg)

Nv′ = specific volume of air at nozzle (ft3/lb)

Nv = specific volume of air at DB and WB of nozzle, but at standard barometric pressure (ft3/lb) RATN = humidity ratio at nozzle (lb moisture / lb dry air)

The flow rate of standard air is calculated as follows:

NvCFMSCFM

′×=

075.0

F-6.2 CEWC Performance.

F-6.2.1 Wet-Bulb Approach (ºF). The difference between the temperature of the water leaving the sump and the wet-bulb of the outdoor air.

OASumpWB WBTApp −=

F-6.2.2 Ventilation Air Pre-cooling Capacity (BTU/hr). The sensible capacity of the CEWC to pre-cool the ventilation airflow in the dry passages. The CEWC has no latent capacity.

)(60 , VAOAVAAirVAPCAirVAPC DBDBCFMCpq −××××= ρ where,


0857.02

)(448.1, +

+×−Ε−= VAOA

VAPCAirDBDB

ρ

(Source: previous DEG monitoring plan) and,

FBtu/lbm/ 2410 °= .Cp Air F-6.2.3 Indirect Evaporative Cooling Effectiveness.

OAOA

VAOAEvapInd WBDB

DBDBEFF−−

=..

F-6.2.4 Dry Passage Pressure Drop (inH2O).

SumpOADry PPPD −= F-6.2.5 Wet Passage Pressure Drop (inH2O).

CEWCESumpWet PPPD −= F-6.3 Aircoil performance.

F-6.3.1 Aircoil Sensible Capacity (BTU/hr). (Source: ASHRAE 37)

( )NN

SAVARAPAirSAAircoil RATv

DBDBCCFMqs+′

−×××= +

1)(60

where, NPAir RATC ×+= 444.024.0

and, ( )

SA

VAVARAVASAVARA CFM

DBCFMDBCFMCFMDB ×+×−=+

and,

( )NN

NN RATP

vv+

×=′

192.29

and, RATN = humidity ratio at nozzle (lb moisture / lb dry air) PN = absolute pressure at nozzle throat (in. Hg)


Nv = specific volume of air at DB and WB of nozzle, but at standard barometric pressure (ft3/lb)


F-6.3.2 Aircoil Total Cooling Capacity (BTU/hr). Equal to the compressor capacity. Aircoil cooling capacity is determined by performing an enthalpy balance on the air across the coil. (Source: ASHRAE 37)

( )NN

SAVARASAAircoil RATv

hhCFMqc+′

−××= +

1)(60

where, ( )

SA

VAVARAVASAVARA CFM

hCFMhCFMCFMh ×+×−=+

and,

( )NN

NN RATP

vv+

×=′

192.29

and, RATN = humidity ratio at nozzle (lb moisture / lb dry air) PN = absolute pressure at nozzle throat (in. Hg)


Nv = specific volume of air at DB and WB of nozzle, but at standard barometric pressure (ft3/lb)

To calculate h (enthalpy), use the equations in 6.1.1 or 6.1.2. Select either WB or RH based on confidence in data. F-6.3.3 Aircoil Latent Capacity (BTU/hr). Latent capacity is the difference between the cooling capacity and the sensible capacity.

AircoilAircoilAircoil qsqcql −=

F-6.4 Compressor performance. F-6.4.1 Compressor EER.

Comp

AircoilComp W

qcEER =

F-6.4.2 Compressor COP.

Comp

AircoilComp W

qcCOP×

=412.3

F-6.5 Overall system cooling performance.

F-6.5.1 Overall Sensible Capacity (BTU/hr). The sum of the sensible capacity of the aircoil and the CEWC ventilation air pre-cooling.


VAPCAircoilOverall qqsqs += F-6.5.2 Overall Latent Capacity (BTU/hr). All latent cooling is delivered via the aircoil.

AircoilOverall qlql = F-6.5.3 Overall Total Cooling Capacity (BTU/hr).

VAPCAircoilOverall qqcqc += F-6.5.4 Overall EER.

Total

OverallOverall P

qcEER =

F-6.5.5 Overall Latent Fraction.

Overall

Aircoil

qcqlLF =

F-6.5.6 Supply/Return Airflow Rate. (CFMSA) Use equations in 6.1.3. F-6.5.7 Outdoor Airflow Rate. (CFMOA) Use equations in 6.1.3. F-6.5.8 Ventilation Airflow Rate. (CFMVA) Determined by the static pressure at the V/A fan inlet (PVFS). Calibration of this pressure to CFMVA will be done before any test runs. F-6.5.9 System Pressure Drop. (inH2O) Across entire indoor air loop. Should satisfy F-5.4.

( )RASATotal PPPD −−=

F-6.6 Overall system heating performance.

F-6.6.1 Heating Capacity (BTU/hr). There are two ways to determine the heating capacity. The more accurate method is an energy balance on the water in the heating aircoil.

( )tReHeatHeatSupHeaterWaterWater TTGPMCpqh −×××= ρ where,

lbm/gal. 348.Water =ρ and

FBtu/lbm/ 01 °= .CpWater


The second method is an energy balance on the air, which is calculated the same way as the sensible cooling calculation. See 6.3.1.

Aircoilqsqh =

F-6.6.2 Heating Efficiency.

HCMCFMqhEFF

GasHeat ×

=

F-6.6.1 Heat Recovery Effectiveness.

OARA

OAVA.cReHeat DBDB

DBDBEFF−−

=


F-7. Test Setup Testing of the HyPak prototype will be done at Des Champs Technologies (DCT) facilities in Natural Bridge Station, Virginia. DCT’s “ASHRAE” loop will be used to simulate the outdoor conditions described in Section 4. The test setup is shown in Figure 1.

Figure F-1: Test Setup


F-8. Methodology The test sequence is outline below. F-8.1 Unit Startup. The prototype will be started and operation of each system will be verified. F-8.2 Calibration. The instrumentation will be calibrated according to Section 10. F-8.3 Ventilation Airflow Calibration. In Phase 2, we used a Duct Blaster from the Energy Conservatory for the variable-speed ventilation air fan. When used with the APT system, the Duct Blaster provides airflow rate within 2% accuracy. However, the Duct Blaster is a specialized product not intended for OEM application. For the Phase 3 prototype, we specified a backward curved plenum fan from Continental Fan powered by a 1/3 hp electronically commutated motor (ECM) from General Electric. To measure the V/A rate we will use a static pressure tap on the inlet cone of the plenum fan. (This is similar to how the Duct Blaster measures airflow rate.) After we use this strategy for the laboratory test unit, we will employ it on the field test unit (and production HyPak units afterwards) for a feedback loop to maintain constant V/A with varying supply blower speeds and R/A pressures. Before we can use static pressure to measure V/A rate, we have to calibrate it against several known airflow rates. This will be done with the flow nozzles in the indoor loop as shown in Figure 2. The uncertainty of the V/A rate will be at least +/-3%. Fortunately, this error will not affect the values determined in the critical test run at ARI standard conditions, because this run has no V/A.


Figure F-2: V/A rate calibration setup

F-8.4 Setup. The prototype will be installed in the laboratory as described in Section 7. The instrumentation will be installed as described in Section 9. F-8.5 Full-load Cooling Test Runs. In the baseline testing, all cooling performance parameters from Section 5 (5.1 to 5.4) shall be evaluated at the cooling conditions listed in Section 4. F-8.6 Partial Load Cooling Test Runs. In order to evaluate cycling operation of HyPak, the unit will be operated at a partial load. This test will be done at Low Temperature Cooling Operating conditions from Table 1. The compressor and/or other components will be cycled to keep supply air dry-bulb temperature within a pre-determined deadband. F-8.7 Full-load Heating Test Runs. Heating performance parameters in 5.5 will be evaluated at the heating conditions listed in Section 4.


F-8.8 Fan Balancing. The supply fan and CEWC tower fan will be operated at a variety of speeds to evaluate the interaction between the fans and its impact on supply (return), CEWC dry passage, CEWC wet passage and ventilation (exhaust) airflow rates. It is not necessary to operate the compressor or pumps, or to condition the air streams, unless it is determined that the difference in pressure drop between the wet and dry aircoil is significant. Upon completion of the tests described here, a test report will be produced by DEG and LBNL. The prototype will remain in DCT’s lab for further product refinement in anticipation of pilot production. After establishing a performance baseline for the as-designed prototype, modifications to the system will be evaluated to determine whether or not they should be incorporated into the design of the Phase 3 prototype. A second prototype of the same specifications will be built alongside the laboratory test unit. The second prototype will be installed in the field and monitored for six to twelve months. It will likely be installed at McClellan Park outside Sacramento, California. See the Field Test Plan for more information.

F-9. Instrumentation The HyPak prototype will be instrumented using two separate systems. Most sensors will be monitored by a data logger, and pressure data will be monitored by a pressure transducer with integrated data logger. Many locations have two sensors to provide back-up and “reality checks.” These sensors will be checked against each other, and in the event of a discrepancy, the sensor with which we have more confidence will be used. For instance, DB will be measured with both thermocouple grids and single location RTDs. The thermocouple grids, once calibrated, should have a higher accuracy than the RTDs, and they will not be impacted as much by a flow which is not well-mixed. However, calibrating the thermocouples grids may be difficult or a junction may be weakened during the installation after calibration. On the other hand, the RTDs were recalibrated by the factory and have a built-in sender unit to eliminate noise or other signal errors. In general, the more accurate sensor is less robust than the back-up. The more accurate sensor is indicated with ' and the more robust with ". In the case of DBSA, the thermocouple grid is DB'SA and the RTD is DB"SA. The WB RTDs are backed-up with RH sensors with sender units. Additional backup instruments are a hand-held RH probe and a mercury/glass thermometer. F-9.1 Sensors (Except Pressure). Table 2 shows the data points that will be monitored with the data logger, a DataTaker DT800. The DT800 is capable of monitoring 12 differential channels (or 42 with shared terminals, or any mix), 4 digital and 3 high speed pulse signals. This is not enough analog channels, so an expansion module will also be used. It provides an additional 10 to 30 analog channels.


Table F-2: DataTaker Monitored Data Points

Parameter Name Description Sensor Type DB"SA TASR supply air dry-bulb temperature (RTD) RHSA RHS supply air relative humidity

combination RTD/RH

WBSA WBS supply air wet-bulb temperature wet-sock RTD, direct reading

DB"RA TARR return air dry-bulb temperature (RTD) RHRA RHR return air relative humidity

combination RTD/RH

WBRA WBR return air wet-bulb temperature wet-sock RTD, direct reading

DB"OA TAOR outdoor air dry-bulb temperature (RTD) RHOA RHO outdoor air relative humidity

combination RTD/RH

DB"VA TAVR ventilation air dry-bulb temperature (RTD) RHVA RHV ventilation air relative humidity

combination RTD/RH

WTotal WT total system power watt transducer A WSF WSF supply fan power watt transducer B WTF WTF tower fan power watt transducer B WComp WC compressor power watt transducer A WVF WVF ventilation fan power watt transducer C TNozzle TANZL indoor air nozzle throat temperature RTD with sender DB'SA TASTC supply air dry-bulb temperature (thermocouple) type T thermocouple grid DB'RA TARTC return air dry-bulb temperature (thermocouple) type T thermocouple grid DB'OA1 TAO1 left side outdoor air dry-bulb temperature type T thermocouple grid DB'OA2 TAO2 right side outdoor air dry-bulb temperature type T thermocouple grid

DB'VA TAVTC ventilation air dry-bulb temperature (thermocouple) type T thermocouple grid

DBEA TAE exhaust air dry-bulb temperature type T thermocouple grid

DBRA+VA1 TARV1 mixed return and ventilation air dry-bulb temperature 1 type T thermocouple grid



TSump TWSUMP sump water temperature type T immersion thermocouple

THeatSup TWHS water heater supply temperature type T immersion thermocouple

THeatRet TWHR water heater return temperature type T immersion thermocouple

TRef TREF reference temperature RTD, direct reading GPMCond FLC condenser loop flowrate flowmeter GPMHeat FLH water heater flowrate flowmeter CFMGas GF natural gas flow rate gas meter


F-9.2 Pressure Sensors. Pressure measurements will be made with Automated Performance Testing System from the Energy Conservatory. This device has eight differential pressure transducers and an integrated data logger. This unit was used in Phase 2 with much success because it can automatically convert pressure data from a Duct Blaster in CFM. Although we will not use the Duct Blaster in Phase 3, the APT system is useful because of its ability to accurately monitor eight pressure channels with a convenient graphic interface. The pressure data points are listed in Table 3.

Table F-3: Pressure Data Points

Parameter Name Description Reference Location PSA PS supply duct static pressure outdoor air inlet PRA PR return duct static pressure outdoor air inlet POA PO outdoor air inlet static pressure ambient PVFS PVFS ventilation fan inlet cone static pressure outdoor air inlet PIND PIND indoor loop flow nozzle differential pressure NA PINS PINS indoor loop flow nozzle static pressure outdoor air inlet POUTD POUTD outdoor loop flow nozzle differential pressure NA POUTS POUTS outdoor loop flow nozzle static pressure outdoor air inlet PEA PE tower exhaust static pressure outdoor air inlet PSump PSUMP sump static pressure outdoor air inlet PCEWCE PCEWCE CEWC exhaust static pressure outdoor air inlet PSF PSF supply fan differential pressure NA

F-9.3 Sensor Specification. Table 4 shows specifications for the sensor types. The hand-held RH probe will be used to monitor the tower exhaust air. Because this air was saturated or nearly saturated for all test runs in Phase 2, we assume that will be the case again in Phase 3. Because the saturated air destroyed one of the combination DB/RH sensors in Phase 2, we will use a hand-held probe to intermittently measure the RH of that air. The hand-held probe can recover from 100% RH (water condensing on sensor), and will read up to 99% with no loss of accuracy. The hand-held probe will also be used to spot-check the readings from the four installed combination DB/RH sensors. The mercury/glass thermometer is for calibration of the thermocouples and for occasional “reality checks.”


Table F-4: Sensor Specifications

Type Application Manufacturer/Model Signal Span Sensor Accuracy1

Total Accuracy1,2

RH relative humidity 4-20 mA (passive) 0 – 99% RH ±2 RH % ±2 RH % RTD (combination + sender) dry-bulb temperature

General Eastern MRHT3-2ID4 4-20 mA (passive) 32 - 132 ºF ±0.5 ºF ±0.52 ºF

RTD (direct reading) wet-bulb, water temperature

Therm-X D-SP-4TT-A316-06-300ST 4 wire resistance 0 - 500 ºF ±0.35 ºF3 ±0.52 ºF3

RTD (with sender unit) dry-bulb temperature Automation Comp. A/100-LT-2W-D-8 4-20 mA (passive) -328 - 392 ºF ±0.54 ºF ±0.7 ºF

Flowmeter water flowrate Onicon F-1300 800 pulses/gal 0.8-38 GPM ±1.0%4 ±1.4%4 Type T immersion thermocouple water temperature Watlow (spec. lim.)

ACGC0F060U8000 ~0-3 mV 0-160 ºF ±0.2 ºF ±0.4 ºF5,6

Type T thermocouple grid dry-bulb temperature Watlow type T special limits of error wire ~0-3 mV 0-160 ºF ±0.2 ºF ±0.4 ºF5,6

Watt transducer A 240 V 3 phase electrical power

Ohio Semitronic PC5-113E 4-20 mA (active) 0-8000 W ±0.78%7,

±1.25%8 ±0.80%7, ±1.27%8

Watt transducer B 240 V 3 phase electrical power

Ohio Semitronic PC5-005E 4-20 mA (active) 0-2000 W ±1.07%9,

±1.63%10 ±1.09%9, ±1.65%10

Watt transducer C 240 V 1 phase electrical power

Ohio Semitronic PC5-107E 4-20 mA (active) 0-500 W ±1.49% ±1.51%

Gas flowmeter gas flow Equimeter R275P 1 pulse/ft3 0-275 ft3/min ±1% ±1.4%11

Hand-held RH/RTD probe relative humidity and dry-bulb temperature Vaisala HMI41 NA 0-100% ±2 RH %,

±0.5 ºF ±2 RH %, ±0.5 ºF

Mercury/glass thermometer water temperature Ertco FP40 (SAMA#) NA 30-124 ºF ±0.2 ºF ±0.2 ºF

Pressure (8-channel) absolute and differential pressure

Energy Conservatory APT-8 RS-232 to PC ±400 Pa ±1% ±1%

1 All % accuracy values are of reading, based on an estimated reading from Phase 2 data 2 Includes DT800 error where applicable (0.02% voltage and current, 0.17% RTDs, 0.3 °F type T thermocouples) and ref. junction error 3 for WB measurement, does not include error due to cotton wicking sock 4 0.5% at calibrated flow rate of 20 GPM, 2% across span, determine exact accuracy after run 5 using isothermal water bath with RTD for reference temperatures (±0.5 °F), otherwise add ±0.5 °F for on-board DT sensor 6 once calibrated with ±0.2 °F mercury/glass thermometer. Without calibration sensor accuracy is ±0.9 °F and total accuracy is ±1.7 °F. 7 for total system power 8 for compressor power 9 for supply fan power 10 for tower fan power 11 at full water heater output over 1 hr steady-state interval

F-9.4 Sensor Locations. Sensor locations in the prototype are shown in Figure 3.


Figure F-3: Sensor Locations


F-9.5 Thermocouples. For maximum accuracy, the reference junction of the type T thermocouples will be placed in an isothermal water bath at ambient temperature. The temperature of the isothermal bath (2 liters of distilled water continuously mixed by a magnetic stirrer) will be measured by a Class A RTD. For DB measurement, thermocouple grids wired in parallel will provide average value. Thermocouples are located at the “center of segments of equal cross-sectional area” as described in ASHRAE 41.1 (6.7). The flow is assumed to be reasonably uniform. If time allows, the uniformity of flow will be confirmed with a traverse. 18” round ducts will be used for supply, return and tower exhaust. With 3000 CFM, the flow will be turbulent and should be well mixed. (The plenum-style supply fan should contribute as well.) The design of the thermocouple grids to be used at those locations is shown in Figure 4, with the equal area segments delineated by dashed lines.

Figure F-4: Thermocouple grid in round ducts

At the outdoor air inlet and ventilation air outlet locations, the opening is roughly 48” x 10.” The design of the thermocouple grids to be used at those locations is shown in Figure 5.


Figure F-5: Thermocouple grid in rectangular locations

It is not required that we measure the mixed return air and ventilation air directly. Knowing the airflow rate of both streams and their DB and RH (and thus enthalpy), we can calculate the values for the mixed air. However, the validity of this resulting data could be affected by problems with any of a number of systems; therefore we will use a thermocouple grid at the upstream side of the filter to measure DB directly. If there is a discrepancy between the measured mixed air DB and the calculated DB (beyond sensor tolerance) we will know there is a problem. This provides a direct backup to the V/A flowrate measurement. Unlike the other grids, the thermocouples at this location will not be averaged into a single data point. We cannot assume that the flow distribution through the filter will be uniform because of the low pressure drop of the filter/aircoil and the short distance between the V/A fan and the filter. The filter area is divided into three equal size vertical regions, each with a vertical thermocouple grid in the middle. We expect that the middle area will have the highest flow because of the V/A fan. Each of these thermocouple grids will be monitored separately by the DataTaker, allowing us to investigate different weightings to match the data produced by the static port on the V/A fan inlet cone. The three grids (TAV1, TAV2, TAV3) are shown in Figure 6.


Figure F-6: Thermocouple Grid at Filter Face

The thermocouple grids will be wired in parallel to produce an average value, as shown in Figure 8 and described in ASHRAE 41.1 (10.7). Because the thermocouples are type T, the measuring junction can be made by twisting and soldering, as described in ASHRAE 41.1 (10.8). The two connection points where all of the Cu and Cu-Ni wires are joined should not be soldered to prevent dissimilar materials from creating a junction.


Figure F-7: Wiring Thermocouple Grids

F-9.6 RTDs. RTDs offer higher accuracy than thermocouples and are more stable.

F-9.6.1 Wet-bulb Measurement. The Wet-bulb measurement has a large impact on the accuracy of the capacity and EER calculations. 4-wire Class A RTDs will be covered in a cotton wicking sock similar to the arrangement shown in Figure 8.

Figure F-8: Typical Wet-Bulb Measurement (Source ASHRAE 41.1)

F-9.7 Power Measurement. The locations of the watt transducers are shown on the electrical schematics in the Appendix. F-9.8 Condenser Loop Measurement. The locations of the flow meter and sump water temperature sensor are shown on the piping schematic in the appendix.


F-9.9 Airflow Measurement. Airflow rates will be measured using flow nozzles in accordance with ASHRAE 37 and 51. Figure 9 shows the nozzle arrangement.

Figure F-9: Flow Nozzles (Source ASHRAE 37)

Nozzles will be used for both the indoor loop and outdoor air inlet. The ventilation airflow rate will be measured using the static pressure at the V/A blower inlet cone. The calibration of the static pressure values is described in 8.2. F-9.10 Refrigeration System. Data about the refrigeration conditions will not be logged. The system will be setup using standard mechanical saturation pressure gauges at the evaporator and condenser. These gauges also have a scale for evaporating and condensing temperatures. In addition, thermocouple probes will be used to measure superheat and subcooling, also required for system setup. Although these values will not be logged, they will be recorded manually at steady-state. With these values, the compressor capacity, EER, power, current and mass flow can be determined from the compressor tables. They will be a “reality check” for the measured power and the calculated capacity and EER.

F-10. Calibration The calibration status of each sensor is listed in Table 5.

Table F-5: Sensor Calibration Status

Manufacturer/Model Type Calibration1 NIST certificate General Eastern MRHT3-2ID4 RH/RTD factory recalibrated Yes Therm-X D-SP-4TT-A316-06-300ST RTD (direct reading) on-site No


Automation Components A/100-LT-2W-D-8 RTD (with sender unit) DEG recalibrated No

Onicon F-1300 Flowmeter phase 2 No

Watlow ACGC0F060U8000 Type T immersion thermocouple phase 2 No

Watlow type T special limits of error wire – twisted/soldered

Type T thermocouple grid on-site No

Ohio Semitronic PC5-113E Watt transducer A new - factory calibrated Yes

Ohio Semitronic PC5-005E Watt transducer B new - factory calibrated Yes

Ohio Semitronic PC5-107E Watt transducer C new - factory calibrated Yes

Equimeter R275P gas flowmeter phase 2 No

Vaisala HMI41 hand-held RH/RTD probe

new - factory calibrated No

Ertco FP40 (SAMA#) Mercury/glass thermometer

new - factory calibrated No

Energy Conservatory APT-8 pressure (8-channel) factory recalibrated Yes 1 Phase 2: sensor is retained from phase 2 and is not important enough to merit recalibration

DEG recalibrated: instrument not critical – recalibrated at DEG facility On-site: will be calibrated during test setup Factory recalibrated: retained from phase 2 and returned to manufacturer for calibration New – factory calibrated: new device calibrated by manufacturer to match as-new accuracy

To calibrate the RTDs and thermocouples, we will use a glass filled thermometer accurate to ±0.2 ºF in the isothermal water bath. A magnetic stirrer equipped with a heater will be used to calibrate the thermocouples at two or three temperatures appropriate for the range of expected temperatures. Calibration data will then be entered in the DataTaker program. In addition, the thermocouple grids will be installed in the same duct and checked against each other with full airflow.

F-11. Error Analysis An error analysis was completed for the Standard Rating Condition test run. Where possible, data from Phase 2 testing was used. For the nozzle parameters, values were estimated. The estimated errors for the major parameters are shown in Table 6. Also shown is the error using the DB and WB (±0.2 °F instead of ±0.4 °F and ±0.5 °F, respectively) tolerances specified in ASHRAE 37.

Parameter Estimated Error

Error with ASHRAE 37 tolerances

Flow Rate (SCFM) 1.4% 1.4% Capacity (BTU/hr) 8.1% 4.2%

EER 8.9% 6.2%

The error for the other test runs should be similar. The error analysis will be repeated using the actual test data and included in the Test Report.

March 25, 2004 DE-FC26-00NT40991 – HyPak – Final Report Page G-1

Appendix G: Laboratory Testing Results

HyPak Phase 3 Laboratory Test Results

Units2/9/2004 2/9/2004 2/4/2004 2/9/2004 2/4/2004 2/9/2004 2/9/2004 2/4/2004 12/14/2003

10:38 11:25 15:29 12:00 11:37 13:50 13:19 13:00 13:45OFF OFF OFF OFF ON OFF OFF ON OFF

CLOSED OPEN CLOSED OPEN OPEN CLOSED OPEN OPEN CLOSEDrate SCFM 2183 2189 2193 2189 2166 2184 2243 2146 1660DB ºF 96.4 95.5 94.9 95.6 94.8 104.4 104.6 106.1 100.0RH % 36.1 38.5 25.8 37.9 23.6 19.6 19.0 10.0 43.2WB ºF 74.4 74.7 68.5 74.5 67.4 71.4 71.1 66.1 80.3DP ºF 65.3 66.4 54.6 66.0 52.0 54.8 54.1 38.4 73.8

enthalpy btu/lb 37.88 38.23 32.77 38.06 31.83 35.18 34.98 30.84 43.87rate SCFM 2987 2991 3003 3005 3005 2993 2997 2993 2989DB ºF 80.3 79.9 76.6 75.8 76.6 79.7 78.7 79.9 81.0WB ºF 65.7 66.0 63.3 63.8 63.4 64.8 64.1 65.1 66.4

enthalpy btu/lb 30.57 30.77 28.74 29.14 28.82 29.86 29.30 30.09 31.11rate SCFM 2987 2991 3003 3005 3005 2993 2997 2993 2989DB ºF 60.7 61.5 58.4 59.6 58.7 59.8 58.9 60.2 59.8WB ºF 58.4 59.4 56.2 56.3 56.3 57.1 56.5 57.9 57.6

enthalpy btu/lb 25.33 25.99 23.92 23.98 23.97 24.49 24.11 24.99 24.81rate SCFM 0 363 0 430 795 0 363 744 0DB ºF 79.6 79.9 76.1 78.9 77.6 78.5 79.5 80.7 85.5RH % 64.5 67.9 49.9 69.1 41.7 47.1 49.8 35.6 60.5WB ºF 70.6 71.9 63.4 71.3 62.1 64.5 66.2 62.5 74.6DP ºF 66.8 68.6 56.3 68.1 62.1 56.9 59.3 51.2 70.5

enthalpy btu/lb 34.56 35.64 28.84 35.14 27.90 29.66 30.93 28.13 38.16rate SCFM 2987 2991 3003 3005 3005 2993 2997 2993 2989DB ºF 80.6 80.4 76.9 77.2 77.4 79.9 79.4 80.7 81.4RH % 48.5 50.8 50.0 51.2 50.0 47.5 46.2 46.0 48.0WB ºF 66.7 67.2 64.1 64.7 64.5 65.8 65.0 66.0 67.2

enthalpy btu/lb 31.30 31.71 29.33 29.81 29.63 30.59 29.98 30.72 31.69rate SCFM 2987 2991 3003 3005 3005 2993 2997 2993 2989DB ºF 58.0 58.6 55.8 55.8 55.6 57.0 56.6 58.0 58.0RH % 96.0 97.0 95.0 97.0 95.0 95.0 95.0 95.0 97.0WB ºF 57.5 58.3 55.2 55.5 55.0 56.3 56.0 57.3 57.7

enthalpy btu/lb 24.78 25.29 23.30 23.52 23.17 24.03 23.80 24.65 24.89ºF 79.5 78.5 76.4 77.9 77.0 77.5 75.5 78.7 84.1ºF 5.1 3.8 7.9 3.4 9.6 6.1 4.4 12.6 3.8

GPM 18 18 18 18 18 18 18 18 18W 5484 5511 5438 5621 4974 5478 5466 4963 5680W 730 793 745 818 720 704 800 659 729W 677 656 616 659 218 673 652 219 648W 3762 3734 3757 3818 3706 3781 3686 3875 3998

Btu/h 0 5874 0 7467 14411 0 9520 19800 0Btu/h 0 4036 0 5405 13684 0 6369 8766 0

ºF 1.5 2.2 1.7 2.1 10.1 2.0 5.2 12.8 -3.3Btu/h 73327 70615 68712 69846 71143 74322 74095 73798 75965Btu/h 87762 86464 81512 85010 87351 88353 83392 81705 91460

0.16 0.18 0.16 0.18 0.19 0.16 0.11 0.10 0.1723.3 23.2 21.7 22.3 23.6 23.4 22.6 21.1 22.9

Btu/h 64580 61207 60245 57463 61042 65235 66621 66656 70130Btu/h 80344 76958 73197 78779 76583 82236 79229 77144 92624Btu/h 64580 67080 60245 64930 75452 65235 76141 86456 70130Btu/h 80345 80994 73197 84184 90266 82236 85598 85910 92624

0.20 0.17 0.18 0.23 0.16 0.21 0.11 -0.01 0.24Btu/h 64580 60939 60245 55694 59755 65235 65945 65327 70130

14.65 14.70 13.46 14.98 18.15 15.01 15.66 17.31 16.31PSI 145 150 145 140 140 145 145 145 150ºF 51 52 52 49 50 52 52 52 52

PSI 375 325 370 315 350 325 325 325 340ºF 112 102 112 100 107 102 102 102 105ºF 57.8 60.5 55.0 54.7 56.0 56.1 56.7 60.0 58.7ºF 85.7 85.1 83.1 83.1 84.5 84.3 83.3 87.0 93.8ºF 6.8 8.5 3.0 5.7 6.0 4.1 4.7 8.0 6.7ºF 26.3 16.9 28.9 16.9 22.5 17.7 18.7 15.0 11.2

in H2O 0.14 0.05 -0.17 0.10 0.22 0.18 0.10 0.20 0.10in H2O -0.16 -0.25 0.00 -0.25 -0.08 -0.10 -0.25 -0.10 -0.20in H2O 0.30 0.30 -0.17 0.35 0.30 0.28 0.35 0.30 0.30in H2O 0.00 0.00 -0.34 0.00 0.30 0.00 0.00 0.30 0.00in H2O -0.37 -0.57 0.15 -0.55 -0.18 -0.34 -0.57 -0.16 -0.47in H2O -0.58 -0.49 -0.48 -0.49 0.00 -0.59 -0.50 0.00 -0.40in H2O -0.94 -0.84 -0.73 -0.86 -0.13 -0.96 -0.88 -0.13 -0.70in H2O 1.06 -1.16 1.09 -1.24 -1.02 -1.02 -1.20 -0.95 1.10

Tower fan differential pressureSupply fan differential pressure

System differential pressureOutdoor air inlet static pressureVentilation air plenum static pressureSump static pressure

SuperheatingSubcoolingSupply duct static pressureReturn duct static pressure

Compressor supply sat. pressureCondensing temperatureSuperheated temperatureSubcooled temperature

Compressor suction sat. pressureEvaporating temperature

Sensible cooling delivered to spaceTotal EER

Total capacity w/o CEWCSystem sensible cooling capacitySystem total cooling capacitySystem latent fraction

Gross (& compressor) cap. at coilLatent fraction of coilCompressor EERSensible capacity w/o CEWC

CEWC VA cooling - delta TCEWC VA cooling - delta hCEWC dew point riseSensible capacity at coil

Total powerSupply blower powerTower fan powerCompressor power

Coil Outlet Air

Sump tempCEWC approachCondenser water flow

Return Air

Supply Air

Ventilation Air


TimeOutdoor Loop BoostVA Damper

Outdoor Air

Western Summer ConditionsARI Standard Rating

Conditions before modifying CEWCValue

Date

Test ARI Standard Rating

Conditions

Modified ARI Standard

ConditionsWestern Maximum Conditions

March 25, 2004 DE-FC26-00NT40991 – HyPak – Final Report Page H-1

Appendix H: Field Test Plan


Field Test Plan for HyPak Phase 3 Prototype

Task 3.3: Install and Field Test Refined PrototypeSeptember 17, 2003

H-1. Objective To gather real-world experience and data from the first HyPak prototype to be installed in the field. The test will run for three to six months and produce data at a wide variety of atmospheric and load conditions. In addition to collecting quantitative data, the test will evaluate installation, operation, maintenance and reliability of the HyPak design, with an emphasis on preventing scale build-up on wetted surfaces. A conventional rooftop packaged unit serving a similar zone in the same building will be monitored to provide a side-by-side comparison. A Final Test Report including the results of the field test will be prepared. The field test will complement the data gathered under controlled laboratory conditions in Task 3.2: Fabricate and Test Refined Prototype.

H-2. Definitions H-2.1 Total Cooling Capacity. The sum of the latent and sensible capacities expressed in Btu/hr. H-2.2 Sensible Capacity. Capacity associated with a change in dry-bulb temperature expressed in Btu/hr. H-2.3 Latent Capacity. Capacity associated with a change in humidity ratio expressed in Btu/hr. H-2.4 Latent Fraction. The ratio of latent capacity to total cooling capacity. H-2.5 Energy Efficiency Ratio (EER). The ratio of cooling capacity in Btu/hr to the sum of the power input values in watts expressed in Btu/W⋅hr. H-2.6 Coefficient of Performance (COP). The ratio of the capacity in watts to the sum of the power input values in watts (dimensionless). H-2.7 Indirect Evaporative Cooling Effectiveness. The ratio of the difference between ventilation air dry-bulb and outdoor air dry-bulb to the difference between outdoor air dry-bulb and outdoor air wet-bulb. H-2.8 Heating Efficiency. The ratio of heating capacity in Btu/hr to the heat content (higher heating value) of the input natural gas in Btu/hr. H-2.9 Heat Recovery Effectiveness. The ratio of the difference between ventilation air dry-bulb and outdoor air dry-bulb to the difference between return air dry-bulb and outdoor air dry-bulb.


H-3. Abbreviations

Abbreviation Description APPWB wet-bulb approach (°F) APT Automated Performance Testing (System) BTU British thermal units CEWC Counter-Flow Evaporative Water Cooler CFM cubic feet per minute CFMBD airflow rate through the Blower Door, as converted by APT System CFMGas natural gas input to water heater (SCFM) CFMSA supply air flow rate (SCFM) CFMVA ventilation air flow rate (SCFM) CpAir specific heat of air (BTU/lb/°F) CT current transformer CTYSump Conductivity of sump water DB dry-bulb temperature (°F) DBEA exhaust air dry-bulb temperature (°F) DBOA outdoor air dry-bulb temperature (°F) DBRA return air dry-bulb temperature (°F) DBRABL return air dry-bulb temperature of baseline unit (°F) DBRA+VA mixed (or weighted average of) return air and ventilation air dry-bulb (°F) DBSA supply air dry-bulb temperature (°F) DBSABL supply air dry-bulb temperature of baseline unit (°F) DBVA ventilation air dry-bulb temperature (°F) DCT Des Champs Technologies DDC direct digital control DEG Davis Energy Group EFFHeat heating efficiency EFFHeatRec. heat recovery effectiveness EFFInd.Evap. indirect evaporative effectiveness EER energy efficiency ratio EERComp compressor energy efficiency ratio EEROverall overall energy efficiency ratio FPM feet per minute GPM gallons per minute GPMAircoil water flow rate through heating aircoil loop GPMCond water flow rate through condenser loop (condenser, CEWC) h enthalpy (btu/lb) hRA+VA mixed return air and ventilation air enthalpy (btu/lb) hRA return air enthalpy (btu/lb) hSA supply air enthalpy (btu/lb) hVA ventilation air enthalpy (btu/lb) HCM local heat content multiplier, usually 1000 btu/ft3


Abbreviation Description HHV higher heating value HVAC heating, ventilation and cooling HHV higher heating value LF overall latent fraction PC personal computer PLC programmable logic controller PRA static pressure in return air duct (in H2O) PSA static pressure in supply air duct (in H2O) PSF differential pressure across supply fan (in H2O) PTF differential pressure across tower fan (in H2O) PVFP differential pressure of Pitot tube at VA fan inlet cone (in H2O) qVAPC ventilation air pre-cooling capacity (BTU/hr) qcAircoil aircoil cooling capacity (BTU/hr) qcOverall overall cooling capacity (BTU/hr) qh overall heating capacity (BTU/hr) qlAircoil aircoil latent capacity (BTU/hr) qlOverall total latent capacity (BTU/hr) qsAircoil aircoil sensible capacity (BTU/hr) qsOverall overall sensible capacity (BTU/hr) RAT humidity ratio (lb moisture / lb dry air) RA return air RH relative humidity RHOA outdoor air relative humidity RHRA return air relative humidity RHRABL return air relative humidity of baseline unit RHSA supply air relative humidity RHSABL supply air relative humidity of baseline unit RHVA ventilation air relative humidity RTD resistive temperature device RTU rooftop packaged unit ρAir,Aircoil average density of air across aircoil (lb/ft3) ρAir,VAPC average density of air across CEWC dry passage (lb/ft3) SA supply air SCFM standard cubic feet per minute (at standard conditions) SComp compressor status SCP condenser pump status SHP heater pump status SSF supply fan status STF tower fan status SVF ventilation fan status TSump temperature of sump water (°F) UV ultraviolet VA ventilation air


Abbreviation Description VFD variable frequency drive WTotal total power(Watts) WB wet-bulb temperature (°F) WBOA wet-bulb temperature of outdoor air (°F)


H-4. Test Conditions H-4.1 Field Test Location. The HyPak prototype will be installed on the former McClellan Air Force Base, now known as McClellan Park, located about 7 miles northeast of downtown Sacramento, California. H-4.2 Field Test Building. The HyPak prototype will be installed on the Lions Gate Hotel and Conference Center. This building is the former Officers’ Club at the McClellan Air Force Base. It is currently undergoing an extensive renovation that includes migration from a 100-ton central system to 10 individual 10-ton RTUs. Trane Precedent units were specified by the renovation project mechanical engineer. The PNYHC120 model is a high-efficiency air-cooled rooftop packaged unit with gas heat and an EER of 11.2, which should make for a good state-of-the-art comparison for HyPak. The HyPak will be installed in lieu of one of the Trane RTUs. H-4.3 Field Test Zone. The HyPak prototype will serve a ballroom in the hotel. The ballroom is served by three 10-ton RTUs (one HyPak and two conventional RTUs). A retractable divider separates one-third of the room. The partitioned section will be served by one of the conventional RTUs. The remaining two-thirds of the ballroom will be served by the HyPak prototype and the other conventional RTU. The conventional RTU will have similar loads and operating conditions to the HyPak unit and will be monitored for a baseline comparison. Although it is a single space, the room has two separate zones, each with its own thermostat. Because the ballroom may be in use at any time of day, the zones require ventilation air 24 hours per day. H-4.4 Supply Airflow. The mechanical engineer specified a supply airflow rate of 4000 CFM. 400 CFM/ton is typical for conventional RTU installations and will be used for the baseline conventional RTU. One of the strategies used by HyPak to reduce energy consumption is to deliver 300 CFM/ton of supply air in a duct system designed for the typical 400 CFM/ton. This results in a much lower pressure drop, reducing supply blower motor power consumption. In order to satisfy the same building load with less supply air, the temperature of the air must be lower by about 3 ºF during peak conditions. This strategy would not work for a conventional RTU because the lower supply air temperature, combined with the lower airflow rate, would result in condensate freezing on the coil in some conditions. The large size of the evaporator in HyPak means that the coil temperature can be several ºF higher for the same supply air temperature, more or less eliminating this danger. H-4.5 Ventilation Airflow. The mechanical engineer of the renovation project has specified a ventilation airflow rate of 1000 CFM for all three units serving the ballroom. Both the HyPak unit and the conventional RTU will supply 1000 CFM of ventilation air.

H-5. Performance Parameters to be Evaluated Most parameters rely on knowledge of airflow rates. Unlike the lab testing in Task 3.2, there is no straightforward way to continuously monitor supply airflow rate. After installation of the HyPak prototype, we will measure the supply airflow rate using a Blower Door with the supply


blower is operating at maximum speed. We will be able to use that flow rate to evaluate the parameters below for any instances when the blower is operating at maximum speed. H-5.1 General Equations.

H-5.1.1 Enthalpy from relative humidity (BTU/lb). Enthalpy (h) is calculated using the following approximation based on air temperature and relative humidity. (Source: fit to data by DEG in previous monitoring)

( )DBRATDBh ×+×+×= 444.09.106024.0 where,

ZZRAT

−×

=26.11013

6219.0

RAT = humidity ratio (lb. of moisture / lb. of dry air) and,

100112.6 YRHZ ××

=

and, 5432 012346.0041667.016393.05.01 XXXXXY ×+×+×+×++=

and,

+

×

−=

14257523467818

.TT

.T

.XC

CC

and,

( )9532 ×−= DBTC

H-5.2 CEWC Performance.

H-5.2.1 Wet-Bulb Approach (ºF). The difference between the temperature of the water leaving the sump and the wet-bulb of the outdoor air.

OASumpWB WBTApp −=

H-5.2.2 Ventilation Air Pre-cooling Capacity (BTU/hr). The sensible capacity of the CEWC to pre-cool the ventilation airflow in the dry passages. The CEWC has no latent capacity.

)(60 , VAOAAirVAPCAirVAVAPC DBDBCpCFMq −××××= ρ where,

0857.02

)(448.1, +

+×−Ε−= VAOA

VAPCAirDBDB

ρ

(Source: previous DEG monitoring plan) and,

(1)

(2)

(3)

(4)

(5)

(6)

(7)

(8)

(9)


FlbmBTU 241.0

°×=AirCp

H-5.2.3 Indirect Evaporative Cooling Effectiveness.

OAOA

VAOAEvapInd WBDB

DBDBEFF−−

=..

H-5.3 Aircoil performance.

H-5.3.1 Aircoil Sensible Capacity (BTU/hr).

)(60 , SAVARAPAirAircoilAirSAAircoil DBDBCCFMqs −××××= +ρ where,

0857.021

61

31448.1, +

×+×+××−Ε−= SAVARAAircoilAir DBDBDBρ

and,

FlbmBTU 241.0

°×=AirCp

and, ( )

SA

VAVARAVASAVARA CFM

DBCFMDBCFMCFMDB ×+×−=+

H-5.3.2 Aircoil Total Cooling Capacity (BTU/hr). Equal to the compressor capacity. Aircoil cooling capacity is determined by performing an enthalpy balance on the air across the coil.

)(60 , SAVARAAircoilAirSAAircoil hhCFMqc −×××= +ρ where,

0857.021

61

31448.1, +

×+×+××−Ε−= SAVARAAircoilAir DBDBDBρ

and, ( )

SA

VAVARAVASAVARA CFM

hCFMhCFMCFMh ×+×−=+

To calculate h (enthalpy), use the equations in Section 5.1.1. H-5.3.3 Aircoil Latent Capacity (BTU/hr). Latent capacity is the difference between the cooling capacity and the sensible capacity.

AircoilAircoilAircoil qsqcql −=

(10)

(11)

(12)

(13)

(14)

(15)

(16)

(17)

(18)

(19)


H-5.4 Overall system cooling performance. H-5.4.1 Overall Sensible Capacity (BTU/hr). The sum of the sensible capacity of the aircoil and the CEWC ventilation air pre-cooling.

VAPCAircoilOverall qqsqs += H-5.4.2 Overall Latent Capacity (BTU/hr). All latent cooling is delivered via the aircoil.

AircoilOverall qlql = H-5.4.3 Overall Total Cooling Capacity (BTU/hr).

VAPCAircoilOverall qqcqc += H-5.4.4 Overall EER.

Total

OverallOverall W

qcEER =

H-5.4.5 Overall Latent Fraction.

Overall

Aircoil

qcqlLF =

H-5.5 Overall system heating performance.

H-5.5.1 Heating Capacity (BTU/hr). Heating capacity is calculated with an energy balance on the air, which is the same as the sensible cooling calculation. See Section 5.3.1.

Aircoilqsqh =

H-5.5.2 Heating Efficiency.

HCMCFMqhEFF

GasHeat ×

=

H-5.5.3 Heat Recovery Effectiveness.

OARA

OAVA.cReHeat DBDB

DBDBEFF−−

=

(20)

(21)

(22)

(23)

(24)

(25)

(26)

(27)


H-6. Methodology The test sequence is outlined below. H-6.1 Unit Startup. The HyPak prototype will be started and operation of each system will be verified at DCT before the unit is shipped to California. H-6.2 Installation. The HyPak prototype will be installed on the Lions Gate Hotel and Conference Center by Airco, a large Sacramento HVAC installer. The instrumentation will be installed by DEG as described in Section 7. H-6.3 Baseline Rooftop Packaged Unit. The baseline comparison unit will be a Trane Precedent unit (see Section 4.2). If possible, Airco will install this unit on the same day as the HyPak unit. Otherwise, it will be installed within two weeks before or after the HyPak unit. The unit and its thermostat will be started up in the same manner as the other eight Trane units on the building. Instrumentation will be installed on this unit by DEG as described in Section 7. H-6.4 Supply Airflow Rate Measurement. The supply airflow rate will be measured for both the HyPak prototype and the baseline RTU. Measuring supply airflow rate of an installed HVAC unit can be difficult. The zones where the HyPak prototype and the baseline RTU will be installed each have two supply registers and one return register. To measure supply airflow, one of the supply registers will be sealed off. This will direct all of the supply air through the remaining open supply register where it will be measured using a Blower Door from the Energy Conservatory. However, sealing one register will result in a higher pressure drop than during standard operation. To compensate for this, the speed of the fan in the Blower Door will be increased so that the supply outlet pressure at the units is the same as during standard operation. Alternately, it may be more accurate to take two readings, one at each register. The speed of the Blower Door will be adjusted so the pressure at the registers is the same, and then the two values will be added together.

H-6.4.1 HyPak Supply Airflow Rate Measurement. If the supply airflow rate is determined to be too low (less than 3000 CFM or 300 CFM/ton), the frequency at the VFD will be increased. If that is not sufficient, a larger supply blower motor will be installed. Time permitting, we will repeat this test for a few of the lower supply airflow rates at which the unit will operate at. The VA blower should be operating at 1000 CFM during this test. H-6.4.2 Baseline RTU Supply Airflow Rate Measurement. No adjustment will be made to the baseline unit after its supply airflow rate is measured.

H-6.5 Differential Pressure Drop Measurements. In conjunction with the supply airflow rate measurement, we will take differential pressure drop measurements in the HyPak prototype. We will focus on the pressure drops across the supply and tower fans and across the supply and return ducts. See Section 7.3 for more information.


H-6.6 Ventilation Airflow Rate Measurement. For both units, we will confirm that 1000 CFM of ventilation air is being delivered.

H-6.6.1 HyPak Ventilation Airflow Rate Measurement. Direct confirmation of the ventilation airflow rate of the HyPak prototype is not possible because this stream is always combined with other streams, except for when it is in the ventilation air blower. The HyPak prototype has a Pitot tube built into the inlet cone of the ventilation air blower to provide continuous feedback to the controller, which then adjusts the speed of the ventilation air blower to maintain constant CFM, even as the other blowers change speeds when the unit switches between operating modes. The ventilation airflow rate can be adjusted at the keypad on the HyPak controller. We will set it to 1000 CFM and the Pitot tube differential pressure will be measured. This will be confirmed manually with the ventilation blower calibration data from the lab test. If feasible, a duct traverse will also be performed. H-6.6.2 Baseline RTU Ventilation Airflow Rate Measurement. For testing purposes, direct measurement of the ventilation airflow rate of the baseline RTU is easier. There is an opening on the side of the cabinet that allows outdoor air to enter the indoor air stream. During a typical RTU installation, a Flow Hood or a similar device is used to adjust the amount of ventilation air so that the specification is satisfied. A sliding plate is moved to vary the amount of the opening that is blocked. Instead of a Flow Hood, we will use the Blower Door to set the ventilation airflow rate because it is more accurate.

H-6.7 Unit Startup. As in Step 6.1, the HyPak prototype will be started and each system will be checked. Any adjustments to the HyPak controller program will be made at this time. The thermostat will be programmed and normal cooling operation will commence. The thermostat settings for both the HyPak and the baseline RTU will be identical. H-6.8 Monitoring. Both the HyPak prototype and the baseline RTU will be monitored for at least three months. The data will be analyzed and a final test report will be delivered. H-6.9 Water Quality Control. An important aspect of the HyPak field test is to evaluate different methods to mitigate water quality problems. The primary area of concern is scale build-up caused by hardness minerals. Left unchecked, this could foul the surfaces of the CEWC and the open condenser, reducing performance. Biological growth is also a concern for the HyPak team.

H-6.9.1 Water Quality Monitoring. The water quality will be monitored by two methods. First, the conductivity of the sump water will be continuously monitored by the instrumentation datalogger. Second, water samples will be sent to a laboratory three times a week for the first four weeks for chemical and biological analyses. Mineral levels will be compared to the water conductivity to determine the correlation between conductivity and hardness mineral concentration. (Silica is the only major hardness mineral which does not affect water conductivity, so a significant level of silica could lead to scale build-up without any indication from the conductivity sensor.) The make-up line water will be monitored in a similar fashion. Conductivity will be monitored at another installation in the same building. Samples will be sent to the laboratory for


chemical analysis together with the sump water samples. BWI Solutions has been subcontracted to manage the water quality assessment program. H-6.9.2 Triangular Wave Deposit Controller. This device creates an electromagnetic field within the water flowing in the condenser loop. (See Condenser Piping Schematic in Appendix for installation location.) It is typical of several products on the market that modify the ionic charge of metallic particles so that they are attracted to each other. The particles cling to each other rather than the wetted surfaces until they are flushed out of the system. This allows the concentration of hardness minerals to safely reach levels that would otherwise lead to scale build-up. In addition to protecting equipment, this type of device saves water because the system can be run with higher cycles of concentration, resulting in less dumped water. Triangular Wave claims that equipment remains free of scale up to seven cycles of concentration. (Results will vary based on local water chemistry.) These devices are frequently used on cooling towers where high temperatures and high rates of evaporation result in significant scale buildup and/or water consumption. Because of the large volume of sump water found in a typical cooling tower, it is not practical to drain the system when it is not in use. Instead, cooling towers typically use a blowdown cycle where the drain is opened for a period of time to drain a portion of the sump water. The fill valve is opened to top-off the sump. Because the water drained off has a higher concentration of hardness minerals than the line water replacing it, the net concentration of the sump water is lowered. Unlike a cooling tower, the HyPak sump will drain nightly to dry out the wetted surfaces to prevent biological growth. The sump volume is small enough for this to be practical. To prevent scale build-up, the sump will also have to be drained occasionally during the day to maintain low conductivity levels. In all locations except those with very hard water, the Triangular Wave Deposit Controller should eliminate the need to drain the sump beyond the daily dry-out cycle. If the HyPak prototype were to operate at full capacity for 14 hours, the cycle of concentration would reach seven. For the first month of operation, the control program for the HyPak prototype will be modified to only drain the sump at the daily dry-out cycle. Conductivity and water chemistry will be monitored as described in Section 6.9.1 and if dangerous levels of hardness mineral are detected, a dump trigger based on cycles of concentration will be added. At the end of the month, the wetted surfaces will be inspected for scale build-up. H-6.9.3 Conductivity Feedback to HyPak Controller. The HyPak prototype has two identical conductivity sensors in the condenser loop. The first will be logged and the second will be wired to an analog input on the main HyPak controller (Johnson Metasys DX9100 PLC). The program for the controller will drain the sump when the conductivity level reaches a trigger. The trigger is adjustable at the keypad on the controller and it will be set artificially high for the first month to effectively disable this function. In the second month of operation, the Triangular Wave Deposit Controller will be disabled and the trigger will be adjusted to a level suggested by BWI Solutions, probably about 600 µMhos/cm. At the end of the second month, the wetted surfaces will again be inspected


for scale build-up. This method is preferred by the team because it has lower first cost and will be effective regardless of local water conditions. However, it will use more water because of the intraday sump drains. The amount of additional water use will be dependant on evaporation rates (which are in turn determined by cooling loads) and make-up water quality. H-6.9.4 Biological Water Quality Assessment. The water samples will be tested by BWI Solutions for total bacteria counts and fungi and yeast levels. Should we become concerned with biological levels, we will investigate mitigating measures such as UV disinfection of the sump water.

H-7. Instrumentation H-7.1 Data Logger. The sensors will be monitored with a DataTaker DT500. The DT500 is capable of monitoring 10 differential channels (or 30 with shared terminals, or any mix), 4 digital and 3 high speed pulse signals. Data will be logged on a 1-minute interval. H-7.2 Sensors (Except Pressure). Table 1 shows the data points that will be monitored with the DataTaker DT500. The wiring of these sensors and the DT500 is shown in the DataTaker Wiring Schematic in the Appendix.

Table H-1: DataTaker Monitored Data Points

Parameter Name Description Sensor Type DBSA TAS Supply air dry bulb temperature RHSA RHS Supply air relative humidity

Combination RTD/RH

DBRA TAR Return air dry bulb temperature RHRA RHR Return air relative humidity

Combination RTD/RH

DBOA TAO Outdoor air dry bulb temperature RHOA RHO Outdoor air relative humidity

Combination RTD/RH

DBVA TAV Ventilation air dry bulb temperature RHVA RHV Ventilation air relative humidity

Combination RTD/RH

DBSABL BTAS Baseline unit supply air dry bulb temperature RHSABL BRHS Baseline unit supply air relative humidity

Combination RTD/RH

DBRABL BTAR Baseline unit return air dry bulb temperature RHRABL BRHR Baseline unit return air relative humidity

Combination RTD/RH

TSump TWSUMP Sump water temperature RTD (immersion) SComp SC Compressor status On/off status SSF SSF Supply fan status On/off status STF STF Tower fan status On/off status SVF SVF Ventilation fan status On/off status SCP SCP CEWC pump status On/off status SHP SHP Heater pump status On/off status


SCompBL BSC Baseline unit compressor status On/off status WTotal WT Total system power Watt transducer A WTotalBL BWT Baseline unit total system power Watt transducer B CTYSump C1 Sump water conductivity Conductivity sensor GPMCond FLC Condenser loop flowrate Flowmeter CFMGas GF Natural gas flow rate Gas meter

H-7.3 Pressure Sensors. As described in Section 6.5, pressure measurements will be made with an Automated Performance Testing System from the Energy Conservatory. This device has eight differential pressure transducers. The output is transmitted to a PC which logs the data. This unit can automatically convert pressure data from a Duct Blaster in CFM and will be used in for supply airflow rate measurements as well. The APT system will only be used during the setup of the unit to take one-time measurements and will not be left behind to log data. The pressure data points are listed in Table 2.

Table H-2: Pressure Data Points

Parameter Name Description Reference Location PSA PS Supply duct static pressure Outdoor air inlet PRA PR Return duct static pressure Outdoor air inlet PTF PTF Tower fan differential pressure NA PSF PSF Supply fan differential pressure NA

CFMBD CFMBD Blower Door differential pressure converted to CFM NA

PVFP PITOT Ventilation blower inlet cone Pitot tube differential pressure NA

H-7.4 Airflow Measurement. As described in Section 6.4 and 6.6, the airflow will only be measured at the time of installation. We will use a Blower Door from the Energy Conservatory because it is accurate and interfaces with the APT system, which can measure the differential pressure and automatically convert it into CFM. For the HyPak VA flow rate, we will measure the differential pressure at the Pitot tube using the APT system, as described in Section 6.6.1. H-7.5 Sensor Specification. Table 3 shows specifications for the sensor types.


Table H-3: Sensor Specifications

Type Application Manufacturer/Model Signal Span Sensor Accuracy1

Total Accuracy1,2

RTD Dry-bulb temperature 4-20 mA (passive) 7-176 °F ±0.5 °F ±0.75 °F Combination RH Relative humidity

Vaisala HD60Y 4-20 mA (passive) 0 - 100% ±2% ±2.3%

RTD (immersion) Water temperature Automation Comp. ACI/TT100-(3)-I-4-(4) 4-20 mA (passive) 20-120 °F ±0.5 °F ±0.75 °F

On/off status Component go/no current switch Veris Hawkeye 600 split core 24 V closed-

contact NA NA NA

Watt transducer A 240 V 3 phase electrical power Ohio Semitronic PC5-113E 4-20 mA (active) 0-8000 W ±0.78% ±1.03%

Watt transducer B 240 V 3 phase electrical power Ohio Semitronic PC5-062E 4-20 mA (active) 0-20,000 W ±1.03% ±1.28%

Conductivity sensor Water conductivity Sensor Development CS51 + CTC signal card 4-20 mA (passive) 0-2000 µMhos ? ?

Flowmeter Water flow Onicon F-1300 800 pulses/gal 0.8-38 GPM ±0.5%3 ±0.5%3 Gas flowmeter Gas flow Equimeter R275P 1 pulse/ft3 0-275 ft3/min ±1% ±2% Blower Door Air flow Energy Conservatory Blower Door NA 20-5000 CFM NA ±3%4

Pressure (8-channel) Differential pressure and Blower Door conversion to CFM

Energy Conservatory APT-8 RS-232 to PC ±400 Pa NA ±1%

1 All % accuracy values are of reading, based on an estimated reading from Phase 2 data 2 Includes DataTaker error (0.15% voltage, 0.25% current, 0.15% RTDs) 3 at calibrated flow rate of 20 GPM, 2% across span

4 includes APT accuracy H-7.6 Sensor Locations. The locations of most sensors in the HyPak prototype are shown in Figure 1. Electrical sensors (watt transducer and on/off status) are shown in the Electrical Schematic in the Appendix. Sensors in the condenser loop are shown in Figure 1 and in the Condenser Piping Schematic in the Appendix. The baseline unit sensors are not shown, but their installation locations are similar to those on the HyPak prototype.


Figure H-1: Sensor Locations


H-7.7 Combination RTD/RH. RTDs offer higher accuracy than thermocouples and are more stable. H-7.8 Immersion RTD. RTDs offer higher accuracy than thermocouples and are more stable. The immersion RTD used for the field test includes an integrated sender unit that converts the resistance to a 4-20 mA signal. This minimizes interference on long RTD signal wires. H-7.9 Component Status. Power consumption will not be monitored for individual components. To monitor the operation of major components, go/no-go current switches will be used. These simple devices have a torus-shaped coil which senses current moving through it and then close a separate signal circuit. They require 0.5-0.75 A of turn-on current, so it may be necessary to wrap the power line through the torus two times for the pumps. These sensors will be used to ensure that the proper operating modes are selected by the main HyPak controller. H-7.10 Power Measurement. The location of the watt transducer on the HyPak unit is shown on the Electrical Schematic in the Appendix. This unit (Watt transducer A) was selected because it has an internal power sensor that simplifies installation and increases accuracy, particularly with variable frequency drives (VFDs) found on the HyPak motors. VFDs severely distort the waveform of the line power, even “upstream” where the watt transducer is located. Because the internal sensors operate at 10 times the sampling frequency of a conventional external current transformer (CT), they are better at measuring true power. For the baseline RTU, we will also monitor the main power supply to the unit. However, because the total power to the baseline RTU unit will be up to 50 A, it exceeds the capacity (25 A) of the largest watt transducer with internal sensors available from Ohio Semitronic. Instead, a conventional watt transducer with external CTs has been specified. This unit has a 0-40 kW and 0-100 A span, but the power line will be wrapped through the CT twice, resulting in a span of 0-20 kW and 0-50 A to match the anticipated power consumption of the baseline RTU. Because the Trane unit does not have VFDs, there should not be a significant reduction in accuracy with the external CTs. H-7.11 Condenser Loop Conductivity. The electrical conductivity of the sump water will be measured to monitor the content of hardness minerals as described in Section 6.9. The General Purpose Conductivity Card from Sensor Development converts the conductivity signal to a 4-20 mA signal which is logged by the DT500. H-7.12 Condenser Loop Flow Measurement. The locations of the flow meter and sump water temperature sensor are shown on the Condenser Piping Schematic in the Appendix. H-7.13 Natural Gas Consumption. The natural gas consumption by the water heater will be measured by a utility-grade gas flowmeter. Because utility meters are used for cumulative readings and are installed for long periods of time, they have a coarse resolution. This makes it difficult to interpolate consumption rates, but the data should be adequate for an average heating efficiciency calculation.


H-8. Calibration The calibration status of each sensor is listed in Table 4.

Table H-4: Sensor Calibration Status

Sensor Type Manufacturer/Model Calibration1 Combination RTD/RH Vaisala HD60Y New - factory calibrated RTD (immersion) Automation Comp. ACI/TT100-(3)-I-4-(4) New - factory calibrated On/off status Veris Hawkeye split core H900 New - factory calibrated Watt transducer A Ohio Semitronic PC5-113E New - factory calibrated Watt transducer B Ohio Semitronic PC5-062E New - factory calibrated

Conductivity sensor Sensor Development CS51 + general purpose conductivity card New - factory calibrated

Flowmeter Onicon F-1100 Factory recalibrated Gas flowmeter Equimeter R275P Phase 2 Pressure (8-channel) Energy Conservatory APT-8 Factory recalibrated 1 New – factory calibrated: new device calibrated by manufacturer to match as-new accuracy

Factory recalibrated: retained from phase 2 and returned to manufacturer for calibration Phase 2: sensor is retained from phase 2 and is not important enough to merit recalibration

H-9. Uncertainty Analysis The results of an uncertainty analysis on the HyPak prototype are shown in Table 5.

Table H-5: Uncertainty Analysis

Parameter Equation Estimated Uncertainty

Aircoil total cooling capacity (qcAircoil) 16 8.4% CEWC VA pre-cooling Capacity (qVAPC) 8 23.9% Overall total cooling capacity (QcOverall) 24 10.1%

Overall EER (EEROverall) 25 11.1%

Temperature data and airflow rates were projected from Phase 2 test results and the test conditions in Section 4. The CEWC VA error is high because the ventilation airflow rate was assumed to be ±10%. The Pitot tube calibration should be more accurate than that, but there is no way to directly measure the VA flow rate, so a conservative value was used. (The industry standard for performance of production RTUs is ±10%.) The aircoil error should be similar for the baseline RTU, however the absence of the VA pre-cooling in the CEWC will reduce the Overall EER error to about ±9.5%. The error analysis will be repeated for both units using the actual test data and included in the Final Test Report.

March 25, 2004 DE-FC26-00NT40991 – HyPak – Final Report Page I-1

Appendix I: Field Test Results

HyPak - Field Test Data 3/15/04

U

'TWSUMP - Sump water temp

RA flowrate SA DB SA RH SA WB

SA enthalpy RA DB RA RH RA WB

RA enthalpy OA DB OA RH OA WB

OA enthalpy VA DB VA RH VA WB

VA enthalpy Capacity

Total power EER

3/15/2004 12:54:40 74.1 2500 54.8 65.4 42.4 16.36 71.8 60.0 54.0 22.62 86.2 24.4 56.6 24.22 57.8 44.4 42.3 16.32 70390 5575 12.633/15/2004 12:54:50 74.1 2500 54.8 65.4 42.4 16.36 71.7 60.1 54.0 22.59 86.2 24.3 56.6 24.21 58.1 44.4 42.5 16.42 70015 5594 12.523/15/2004 12:55:00 74.1 2500 54.7 65.4 42.3 16.33 71.7 60.1 54.0 22.59 86.2 24.7 56.7 24.27 58.7 44.4 42.9 16.61 70420 5602 12.573/15/2004 12:55:10 74.1 2500 54.7 65.4 42.3 16.33 71.7 60.2 54.0 22.60 86.1 24.2 56.5 24.16 58.0 44.3 42.4 16.38 70520 5604 12.593/15/2004 12:55:20 74.1 2500 54.6 65.4 42.2 16.29 71.6 60.2 53.9 22.55 86.1 24.7 56.6 24.23 58.6 44.3 42.8 16.58 70450 5603 12.573/15/2004 12:55:30 74.1 2500 54.6 65.6 42.3 16.30 71.6 60.3 53.9 22.56 86.1 25.2 56.7 24.30 59.7 44.3 43.6 16.94 70440 5595 12.593/15/2004 12:55:40 74.1 2500 54.5 65.7 42.2 16.27 71.5 60.4 53.9 22.53 86.1 25.0 56.7 24.27 60.3 44.3 44.0 17.14 70415 5585 12.613/15/2004 12:55:50 74.1 2500 54.5 65.9 42.2 16.28 71.5 60.4 53.9 22.53 86.1 24.8 56.6 24.24 59.7 44.2 43.5 16.94 70306 5565 12.633/15/2004 12:56:00 74.1 2500 54.4 66.0 42.1 16.25 71.5 60.5 53.9 22.54 86.0 24.7 56.6 24.20 59.6 44.2 43.5 16.90 70757 5555 12.743/15/2004 12:56:10 74.2 2500 54.4 66.2 42.2 16.26 71.4 60.6 53.8 22.50 86.0 24.6 56.5 24.18 59.2 44.2 43.2 16.77 70272 5543 12.683/15/2004 12:56:20 74.2 2500 54.4 66.4 42.2 16.27 71.4 60.6 53.8 22.50 86.0 24.9 56.6 24.22 59.3 44.2 43.3 16.80 70164 5533 12.683/15/2004 12:56:30 74.2 2500 54.4 66.5 42.2 16.27 71.4 60.6 53.8 22.50 86.0 25.3 56.7 24.28 60.0 44.2 43.8 17.04 70109 5530 12.683/15/2004 12:56:40 74.2 2500 54.3 66.6 42.1 16.24 71.3 60.7 53.8 22.47 86.1 24.7 56.6 24.23 59.7 44.1 43.5 16.93 70086 5546 12.643/15/2004 12:56:50 74.2 2500 54.3 66.7 42.1 16.25 71.3 60.7 53.8 22.47 86.1 24.6 56.6 24.22 59.5 44.1 43.4 16.86 70031 5567 12.583/15/2004 12:57:00 74.2 2500 54.3 66.7 42.1 16.25 71.3 60.7 53.8 22.47 86.1 24.4 56.6 24.19 59.2 44.1 43.2 16.76 70031 5583 12.543/15/2004 12:57:10 74.2 2500 54.3 66.5 42.1 16.24 71.3 60.7 53.8 22.47 86.0 25.0 56.6 24.24 59.0 44.1 43.1 16.70 70140 5595 12.543/15/2004 12:57:20 74.2 2500 54.3 66.5 42.1 16.24 71.3 60.8 53.8 22.48 86.1 25.6 56.8 24.36 59.6 44.1 43.5 16.90 70238 5604 12.533/15/2004 12:57:30 74.2 2500 54.3 66.4 42.1 16.23 71.3 60.8 53.8 22.48 86.1 25.2 56.7 24.30 59.9 44.0 43.7 16.99 70293 5606 12.543/15/2004 12:57:40 74.2 2500 54.2 66.4 42.0 16.20 71.3 60.8 53.8 22.48 86.1 24.7 56.6 24.23 59.7 44.0 43.5 16.93 70698 5605 12.613/15/2004 12:57:50 74.2 2500 54.2 66.4 42.0 16.20 71.3 60.8 53.8 22.48 86.1 24.8 56.6 24.24 59.4 44.0 43.3 16.83 70698 5590 12.653/15/2004 12:58:00 74.2 2500 54.2 66.5 42.0 16.20 71.3 60.8 53.8 22.48 86.0 24.8 56.6 24.21 59.7 44.0 43.5 16.93 70644 5574 12.673/15/2004 12:58:10 74.2 2500 54.2 66.7 42.1 16.21 71.2 60.8 53.7 22.44 85.9 24.9 56.6 24.19 59.8 43.9 43.6 16.95 70061 5554 12.623/15/2004 12:58:20 74.2 2500 54.1 66.8 42.0 16.18 71.2 60.8 53.7 22.44 85.9 24.8 56.5 24.17 59.9 43.9 43.6 16.99 70413 5544 12.703/15/2004 12:58:30 74.1 2500 54.1 66.8 42.0 16.18 71.3 60.9 53.8 22.49 85.7 24.8 56.4 24.10 59.8 43.9 43.6 16.95 70987 5529 12.843/15/2004 12:58:40 74.1 2500 54.1 66.9 42.0 16.18 71.3 60.9 53.8 22.49 85.6 25.4 56.5 24.15 60.4 43.9 44.0 17.15 70933 5523 12.843/15/2004 12:58:50 74.1 2500 54.1 67.1 42.0 16.19 71.3 60.8 53.8 22.48 85.6 25.3 56.5 24.14 60.2 43.9 43.9 17.09 70727 5528 12.803/15/2004 12:59:00 74.1 2500 54.1 67.1 42.0 16.19 71.3 60.8 53.8 22.48 85.6 25.4 56.5 24.15 60.1 43.9 43.8 17.05 70727 5544 12.763/15/2004 12:59:10 74.1 2500 54.1 67.1 42.0 16.19 71.3 60.8 53.8 22.48 85.5 25.4 56.4 24.12 60.4 43.8 44.0 17.15 70727 5570 12.703/15/2004 12:59:20 74.1 2500 54.1 66.9 42.0 16.18 71.2 60.8 53.7 22.44 85.5 25.4 56.4 24.12 60.5 43.8 44.0 17.18 70360 5585 12.603/15/2004 12:59:30 74.1 2500 54.2 66.8 42.1 16.21 71.2 60.8 53.7 22.44 85.5 25.4 56.4 24.12 60.8 43.8 44.2 17.28 70007 5597 12.513/15/2004 12:59:40 74.1 2500 54.1 66.7 42.0 16.17 71.2 60.9 53.7 22.45 85.5 25.7 56.5 24.16 61.5 43.8 44.7 17.52 70566 5604 12.593/15/2004 12:59:50 74.1 2500 54.1 66.7 42.0 16.17 71.2 61.0 53.8 22.46 85.6 25.6 56.5 24.18 61.3 43.8 44.6 17.45 70664 5609 12.603/15/2004 13:00:00 74.1 2500 54.1 66.7 42.0 16.17 71.2 61.0 53.8 22.46 85.6 25.7 56.6 24.20 61.7 43.8 44.9 17.59 70664 5602 12.623/15/2004 13:00:10 74.1 2500 54.1 66.7 42.0 16.17 71.2 61.0 53.8 22.46 85.6 25.4 56.5 24.15 61.4 43.8 44.7 17.49 70664 5588 12.653/15/2004 13:00:20 74.1 2500 54.1 66.9 42.0 16.18 71.1 61.0 53.7 22.41 85.6 25.8 56.6 24.21 61.9 43.8 45.0 17.66 70082 5577 12.573/15/2004 13:00:30 74.2 2500 54.0 67.0 41.9 16.15 71.1 61.1 53.7 22.42 85.6 25.3 56.5 24.14 61.5 43.8 44.7 17.52 70532 5563 12.683/15/2004 13:00:40 74.1 2500 54.0 67.1 42.0 16.16 71.1 61.1 53.7 22.42 85.6 25.0 56.4 24.10 60.5 43.8 44.0 17.18 70478 5541 12.723/15/2004 13:00:50 74.2 2500 54.0 67.2 42.0 16.16 71.1 61.1 53.7 22.42 85.5 24.7 56.3 24.02 60.0 43.7 43.7 17.01 70425 5524 12.753/15/2004 13:01:00 74.2 2500 54.0 67.3 42.0 16.17 71.1 61.1 53.7 22.42 85.4 25.0 56.3 24.03 60.1 43.7 43.8 17.04 70371 5523 12.743/15/2004 13:01:10 74.2 2500 54.0 67.4 42.0 16.17 71.1 61.1 53.7 22.42 85.4 25.3 56.4 24.07 60.6 43.7 44.1 17.21 70318 5527 12.723/15/2004 13:01:20 74.1 2500 54.0 67.5 42.0 16.18 71.1 61.1 53.7 22.42 85.4 25.6 56.4 24.11 61.2 43.7 44.5 17.41 70264 5550 12.663/15/2004 13:01:30 74.1 2500 54.0 67.5 42.0 16.18 71.1 61.2 53.7 22.43 85.4 25.9 56.5 24.15 61.4 43.7 44.6 17.48 70362 5573 12.633/15/2004 13:01:40 74.2 2500 54.0 67.4 42.0 16.17 71.1 61.2 53.7 22.43 85.5 25.5 56.5 24.13 61.4 43.7 44.6 17.48 70416 5590 12.603/15/2004 13:01:50 74.2 2500 54.0 67.3 42.0 16.17 71.1 61.2 53.7 22.43 85.6 26.1 56.7 24.25 62.3 43.7 45.2 17.79 70470 5602 12.583/15/2004 13:02:00 74.2 2500 54.0 67.2 42.0 16.16 71.1 61.2 53.7 22.43 85.7 25.5 56.6 24.20 61.9 43.7 45.0 17.65 70523 5612 12.573/15/2004 13:02:10 74.2 2500 54.0 67.1 42.0 16.16 71.0 61.2 53.6 22.39 85.7 25.1 56.5 24.15 61.2 43.7 44.5 17.41 70101 5611 12.493/15/2004 13:02:20 74.2 2500 54.0 67.1 42.0 16.16 71.0 61.3 53.7 22.40 85.7 25.4 56.6 24.19 61.9 43.7 45.0 17.65 70199 5602 12.533/15/2004 13:02:30 74.2 2500 53.9 67.2 41.9 16.13 71.0 61.4 53.7 22.41 85.8 25.4 56.6 24.22 62.0 43.7 45.0 17.68 70649 5586 12.653/15/2004 13:02:40 74.2 2500 53.9 67.3 41.9 16.13 71.0 61.4 53.7 22.41 85.9 25.4 56.7 24.26 62.0 43.7 45.0 17.68 70596 5576 12.663/15/2004 13:02:50 74.2 2500 53.9 67.5 41.9 16.14 71.0 61.4 53.7 22.41 85.9 25.8 56.8 24.32 62.5 43.7 45.4 17.85 70489 5562 12.673/15/2004 13:03:00 74.2 2500 53.9 67.7 41.9 16.15 71.0 61.4 53.7 22.41 86.0 25.5 56.7 24.31 62.2 43.7 45.2 17.75 70383 5546 12.693/15/2004 13:03:10 74.3 2500 53.9 67.8 42.0 16.15 71.0 61.5 53.7 22.41 86.1 25.4 56.8 24.33 62.0 43.7 45.0 17.68 70427 5537 12.723/15/2004 13:03:20 74.3 2500 53.9 67.9 42.0 16.16 71.0 61.5 53.7 22.41 86.1 25.2 56.7 24.30 63.3 43.7 45.9 18.13 70374 5535 12.723/15/2004 13:03:30 74.3 2500 53.9 68.0 42.0 16.16 71.0 61.4 53.7 22.41 86.2 24.8 56.7 24.28 62.0 43.7 45.0 17.68 70223 5541 12.673/15/2004 13:03:40 74.3 2500 53.9 68.0 42.0 16.16 71.0 61.5 53.7 22.41 86.2 24.4 56.6 24.22 61.5 43.8 44.7 17.52 70320 5557 12.653/15/2004 13:03:50 74.3 2500 53.9 67.9 42.0 16.16 71.0 61.5 53.7 22.41 86.1 25.3 56.8 24.32 61.3 43.8 44.6 17.45 70374 5580 12.613/15/2004 13:04:00 74.3 2500 53.9 67.8 42.0 16.15 71.0 61.5 53.7 22.41 86.1 24.9 56.7 24.26 61.0 43.8 44.4 17.35 70427 5594 12.593/15/2004 13:04:10 74.3 2500 53.9 67.5 41.9 16.14 71.0 61.4 53.7 22.41 86.1 24.8 56.6 24.24 60.1 43.8 43.8 17.05 70489 5600 12.593/15/2004 13:04:20 74.3 2500 53.9 67.4 41.9 16.14 71.0 61.4 53.7 22.41 86.0 25.0 56.6 24.24 60.6 43.8 44.1 17.22 70543 5606 12.58

HyPak - Field Test Data 3/15/043/15/2004 13:04:30 74.3 2500 53.9 67.4 41.9 16.14 71.0 61.5 53.7 22.41 86.0 25.3 56.7 24.28 61.2 43.8 44.5 17.42 70640 5611 12.593/15/2004 13:04:40 74.3 2500 53.9 67.3 41.9 16.13 70.9 61.5 53.6 22.37 86.1 25.1 56.7 24.29 61.3 43.8 44.6 17.45 70218 5606 12.533/15/2004 13:04:50 74.3 2500 53.9 67.3 41.9 16.13 71.0 61.6 53.7 22.42 86.0 25.1 56.7 24.25 61.1 43.8 44.5 17.38 70792 5591 12.663/15/2004 13:05:00 74.3 2500 53.9 67.5 41.9 16.14 71.0 61.5 53.7 22.41 86.0 25.7 56.8 24.34 61.1 43.8 44.5 17.38 70587 5575 12.663/15/2004 13:05:10 74.3 2500 53.9 67.6 41.9 16.14 71.0 61.5 53.7 22.41 86.0 25.6 56.8 24.32 61.5 43.7 44.7 17.51 70534 5560 12.693/15/2004 13:05:20 74.3 2500 53.8 67.6 41.9 16.11 71.0 61.5 53.7 22.41 86.0 25.3 56.7 24.28 61.5 43.8 44.7 17.52 70940 5544 12.803/15/2004 13:05:30 74.3 2500 53.9 67.7 41.9 16.15 70.9 61.5 53.6 22.37 86.0 25.6 56.8 24.32 61.9 43.8 45.0 17.66 70005 5531 12.663/15/2004 13:05:40 74.3 2500 53.9 67.7 41.9 16.15 70.9 61.5 53.6 22.37 86.0 25.4 56.7 24.29 61.5 43.8 44.7 17.52 70005 5521 12.683/15/2004 13:05:50 74.3 2500 53.9 67.8 42.0 16.15 70.9 61.5 53.6 22.37 86.0 25.8 56.8 24.35 61.8 43.7 44.9 17.62 69952 5528 12.663/15/2004 13:06:00 74.3 2500 53.9 67.8 42.0 16.15 71.0 61.5 53.7 22.41 86.0 25.7 56.8 24.34 61.0 43.7 44.4 17.34 70427 5547 12.703/15/2004 13:06:10 74.3 2500 53.9 67.8 42.0 16.15 71.0 61.4 53.7 22.41 86.0 25.4 56.7 24.29 61.0 43.7 44.4 17.34 70329 5571 12.623/15/2004 13:06:20 74.3 2500 53.9 67.7 41.9 16.15 71.0 61.5 53.7 22.41 86.0 26.0 56.9 24.38 61.9 43.7 45.0 17.65 70480 5591 12.613/15/2004 13:06:30 74.3 2500 53.9 67.6 41.9 16.14 71.0 61.5 53.7 22.41 86.1 25.6 56.8 24.36 62.1 43.7 45.1 17.72 70534 5602 12.593/15/2004 13:06:40 74.3 2500 53.9 67.6 41.9 16.14 70.9 61.5 53.6 22.37 86.1 25.2 56.7 24.30 62.1 43.7 45.1 17.72 70058 5608 12.493/15/2004 13:06:50 74.3 2500 53.9 67.5 41.9 16.14 71.0 61.5 53.7 22.41 86.1 25.1 56.7 24.29 61.9 43.7 45.0 17.65 70587 5612 12.583/15/2004 13:07:00 74.3 2500 53.9 67.3 41.9 16.13 71.0 61.5 53.7 22.41 86.1 25.5 56.8 24.34 62.4 43.7 45.3 17.82 70694 5608 12.613/15/2004 13:07:10 74.3 2500 53.9 67.5 41.9 16.14 70.9 61.6 53.6 22.38 86.2 25.5 56.9 24.38 63.0 43.7 45.7 18.02 70209 5589 12.563/15/2004 13:07:20 74.3 2500 53.9 67.6 41.9 16.14 70.9 61.6 53.6 22.38 86.2 25.0 56.7 24.31 61.6 43.8 44.8 17.55 70156 5576 12.583/15/2004 13:07:30 74.3 2500 53.8 67.6 41.9 16.11 70.9 61.6 53.6 22.38 86.3 25.9 57.0 24.47 61.8 43.7 44.9 17.62 70562 5561 12.693/15/2004 13:07:40 74.3 2500 53.8 67.8 41.9 16.12 70.9 61.7 53.6 22.39 86.2 26.1 57.0 24.47 61.6 43.7 44.8 17.55 70553 5544 12.733/15/2004 13:07:50 74.3 2500 53.8 67.8 41.9 16.12 70.9 61.7 53.6 22.39 86.2 24.8 56.7 24.28 61.4 43.8 44.7 17.49 70553 5531 12.763/15/2004 13:08:00 74.3 2500 53.8 68.0 41.9 16.13 70.9 61.7 53.6 22.39 86.3 25.1 56.8 24.36 61.8 43.7 44.9 17.62 70447 5524 12.753/15/2004 13:08:10 74.3 2500 53.8 68.0 41.9 16.13 70.9 61.7 53.6 22.39 86.2 24.8 56.7 24.28 61.7 43.8 44.9 17.59 70447 5531 12.743/15/2004 13:08:20 74.3 2500 53.8 68.0 41.9 16.13 70.9 61.7 53.6 22.39 86.3 25.0 56.8 24.34 61.4 43.8 44.7 17.49 70447 5540 12.723/15/2004 13:08:30 74.3 2500 53.9 68.1 42.0 16.17 70.9 61.7 53.6 22.39 86.3 24.9 56.8 24.33 60.6 43.8 44.1 17.22 69987 5565 12.583/15/2004 13:08:40 74.4 2500 53.9 67.9 42.0 16.16 70.9 61.6 53.6 22.38 86.4 24.6 56.8 24.32 60.9 43.8 44.3 17.32 69996 5588 12.533/15/2004 13:08:50 74.4 2500 53.9 67.8 42.0 16.15 71.0 61.6 53.7 22.42 86.4 24.5 56.7 24.31 61.0 43.8 44.4 17.35 70525 5600 12.593/15/2004 13:09:00 74.3 2500 53.9 67.6 41.9 16.14 71.0 61.6 53.7 22.42 86.5 24.8 56.9 24.39 61.1 43.8 44.5 17.38 70632 5607 12.603/15/2004 13:09:10 74.3 2500 53.9 67.5 41.9 16.14 71.0 61.6 53.7 22.42 86.5 24.3 56.8 24.31 60.5 43.8 44.0 17.18 70685 5611 12.603/15/2004 13:09:20 74.3 2500 53.9 67.4 41.9 16.14 70.9 61.7 53.6 22.39 86.5 24.9 56.9 24.40 61.6 43.8 44.8 17.55 70360 5611 12.543/15/2004 13:09:30 74.4 2500 53.9 67.5 41.9 16.14 71.0 61.7 53.7 22.43 86.5 24.8 56.9 24.39 61.8 43.8 44.9 17.62 70783 5598 12.643/15/2004 13:09:40 74.3 2500 53.9 67.6 41.9 16.14 71.0 61.6 53.7 22.42 86.6 24.4 56.8 24.36 61.5 43.8 44.7 17.52 70632 5584 12.653/15/2004 13:09:50 74.3 2500 53.9 67.7 41.9 16.15 70.9 61.6 53.6 22.38 86.6 24.4 56.8 24.36 60.9 43.8 44.3 17.32 70103 5568 12.593/15/2004 13:10:00 74.4 2500 53.9 67.7 41.9 16.15 70.9 61.6 53.6 22.38 86.7 24.4 56.9 24.40 60.9 43.8 44.3 17.32 70103 5552 12.633/15/2004 13:10:10 74.3 2500 53.8 67.7 41.9 16.11 70.9 61.6 53.6 22.38 86.7 24.2 56.8 24.37 60.8 43.8 44.2 17.28 70509 5537 12.743/15/2004 13:10:20 74.3 2500 53.8 67.8 41.9 16.12 70.9 61.6 53.6 22.38 86.7 24.4 56.9 24.40 61.2 43.8 44.5 17.42 70456 5523 12.763/15/2004 13:10:30 74.3 2500 53.8 67.9 41.9 16.12 70.9 61.7 53.6 22.39 86.7 24.1 56.8 24.35 61.1 43.8 44.5 17.38 70500 5519 12.773/15/2004 13:10:40 74.3 2500 53.8 68.0 41.9 16.13 70.9 61.7 53.6 22.39 86.7 24.5 56.9 24.41 60.5 43.8 44.0 17.18 70447 5532 12.733/15/2004 13:10:50 74.4 2500 53.9 68.0 42.0 16.16 70.9 61.7 53.6 22.39 86.7 24.3 56.9 24.38 60.5 43.8 44.0 17.18 70040 5555 12.613/15/2004 13:11:00 74.3 2500 53.9 68.0 42.0 16.16 70.9 61.7 53.6 22.39 86.7 24.3 56.9 24.38 60.4 43.8 44.0 17.15 70040 5585 12.543/15/2004 13:11:10 74.4 2500 53.9 67.8 42.0 16.15 70.9 61.7 53.6 22.39 86.7 24.8 57.0 24.46 61.6 43.8 44.8 17.55 70147 5604 12.523/15/2004 13:11:20 74.4 2500 53.9 67.7 41.9 16.15 70.9 61.7 53.6 22.39 86.8 24.4 56.9 24.43 62.0 43.8 45.1 17.69 70200 5611 12.513/15/2004 13:11:30 74.4 2500 53.9 67.6 41.9 16.14 70.9 61.8 53.7 22.40 86.7 24.4 56.9 24.40 60.9 43.8 44.3 17.32 70351 5620 12.523/15/2004 13:11:40 74.4 2500 53.9 67.5 41.9 16.14 70.9 61.8 53.7 22.40 86.7 24.2 56.8 24.37 61.1 43.8 44.5 17.38 70404 5610 12.553/15/2004 13:11:50 74.4 2500 53.9 67.6 41.9 16.14 70.9 61.8 53.7 22.40 86.7 24.7 57.0 24.44 61.4 43.9 44.7 17.49 70351 5592 12.583/15/2004 13:12:00 74.4 2500 53.8 67.7 41.9 16.11 70.9 61.8 53.7 22.40 86.8 24.6 57.0 24.46 60.9 43.9 44.3 17.32 70704 5578 12.683/15/2004 13:12:10 74.4 2500 53.8 67.7 41.9 16.11 70.9 61.7 53.6 22.39 86.9 24.0 56.9 24.41 60.5 43.9 44.1 17.19 70607 5562 12.693/15/2004 13:12:20 74.4 2500 53.8 67.8 41.9 16.12 70.8 61.8 53.6 22.36 86.9 24.0 56.9 24.41 60.4 43.9 44.0 17.15 70175 5545 12.663/15/2004 13:12:30 74.4 2500 53.8 67.8 41.9 16.12 70.8 61.8 53.6 22.36 86.9 23.7 56.8 24.37 60.1 43.9 43.8 17.05 70175 5535 12.683/15/2004 13:12:40 74.4 2500 53.8 68.0 41.9 16.13 70.8 61.9 53.6 22.36 86.9 23.8 56.9 24.38 59.7 43.9 43.5 16.92 70166 5530 12.693/15/2004 13:12:50 74.4 2500 53.8 68.0 41.9 16.13 70.8 61.9 53.6 22.36 86.9 24.6 57.0 24.50 60.5 43.9 44.1 17.19 70166 5538 12.673/15/2004 13:13:00 74.4 2500 53.8 68.1 41.9 16.13 70.8 61.9 53.6 22.36 86.8 24.5 57.0 24.45 60.6 43.9 44.1 17.22 70113 5559 12.613/15/2004 13:13:10 74.4 2500 53.8 68.1 41.9 16.13 70.8 61.9 53.6 22.36 86.8 25.0 57.1 24.52 61.0 43.9 44.4 17.36 70113 5578 12.573/15/2004 13:13:20 74.4 2500 53.8 68.0 41.9 16.13 70.8 61.8 53.6 22.36 86.7 24.7 57.0 24.44 61.4 43.9 44.7 17.49 70069 5596 12.523/15/2004 13:13:30 74.4 2500 53.8 67.9 41.9 16.12 70.9 61.8 53.7 22.40 86.7 25.0 57.0 24.49 61.3 43.9 44.6 17.46 70598 5603 12.603/15/2004 13:13:40 74.4 2500 53.8 67.8 41.9 16.12 70.9 61.8 53.7 22.40 86.8 24.9 57.1 24.51 61.6 43.9 44.8 17.56 70651 5615 12.583/15/2004 13:13:50 74.4 2500 53.8 67.7 41.9 16.11 70.8 61.8 53.6 22.36 86.8 25.1 57.1 24.54 61.7 43.9 44.9 17.59 70228 5617 12.503/15/2004 13:14:00 74.4 2500 53.8 67.7 41.9 16.11 70.8 61.8 53.6 22.36 86.9 24.4 57.0 24.47 61.3 43.9 44.6 17.46 70228 5608 12.523/15/2004 13:14:10 74.4 2500 53.8 67.8 41.9 16.12 70.9 61.8 53.7 22.40 86.8 24.9 57.1 24.51 61.0 43.9 44.4 17.36 70651 5585 12.653/15/2004 13:14:20 74.4 2500 53.8 67.9 41.9 16.12 70.9 61.8 53.7 22.40 86.8 25.9 57.3 24.65 61.4 43.9 44.7 17.49 70598 5571 12.673/15/2004 13:14:30 74.4 2500 53.7 67.9 41.8 16.09 70.9 61.8 53.7 22.40 86.8 26.1 57.3 24.68 61.6 43.9 44.8 17.56 71004 5555 12.783/15/2004 13:14:40 74.4 2500 53.8 68.0 41.9 16.13 70.9 61.7 53.6 22.39 86.8 24.5 57.0 24.45 61.1 43.9 44.5 17.39 70447 5542 12.713/15/2004 13:14:50 74.4 2500 53.8 68.1 41.9 16.13 70.9 61.7 53.6 22.39 86.7 24.8 57.0 24.46 61.0 43.9 44.4 17.36 70394 5531 12.733/15/2004 13:15:00 74.5 2500 53.8 68.2 41.9 16.14 70.9 61.8 53.7 22.40 86.7 24.8 57.0 24.46 61.5 43.9 44.7 17.53 70438 5526 12.75

HyPak - Field Test Data 3/15/04

3/15/2004 13:15:10 74.5 2500 53.8 68.2 41.9 16.14 70.9 61.8 53.7 22.40 86.7 24.9 57.0 24.47 61.5 43.9 44.7 17.53 70438 5537 12.723/15/2004 13:15:20 74.5 2500 53.8 68.3 41.9 16.14 70.9 61.8 53.7 22.40 86.7 24.6 56.9 24.43 61.2 43.9 44.5 17.42 70385 5565 12.653/15/2004 13:15:30 74.5 2500 53.8 68.2 41.9 16.14 70.9 61.8 53.7 22.40 86.7 24.9 57.0 24.47 61.6 43.9 44.8 17.56 70438 5597 12.593/15/2004 13:15:40 74.5 2500 53.8 68.0 41.9 16.13 70.9 61.8 53.7 22.40 86.7 24.5 56.9 24.41 61.7 43.9 44.9 17.59 70545 5610 12.573/15/2004 13:15:50 74.5 2500 53.8 67.9 41.9 16.12 70.9 61.9 53.7 22.41 86.7 24.6 56.9 24.43 61.5 43.9 44.7 17.53 70695 5614 12.593/15/2004 13:16:00 74.5 2500 53.8 67.8 41.9 16.12 70.9 61.9 53.7 22.41 86.7 24.7 57.0 24.44 61.3 43.9 44.6 17.46 70748 5627 12.573/15/2004 13:16:10 74.6 2500 53.8 67.8 41.9 16.12 70.9 61.9 53.7 22.41 86.8 25.2 57.1 24.55 62.0 44.0 45.1 17.70 70748 5630 12.573/15/2004 13:16:20 74.6 2500 53.8 67.9 41.9 16.12 70.9 61.9 53.7 22.41 86.8 25.3 57.1 24.57 62.6 44.0 45.5 17.91 70695 5610 12.603/15/2004 13:16:30 74.6 2500 53.8 68.0 41.9 16.13 71.0 61.9 53.7 22.45 86.9 25.2 57.2 24.59 62.3 44.0 45.3 17.80 71119 5596 12.713/15/2004 13:16:40 74.6 2500 53.8 68.2 41.9 16.14 71.0 61.8 53.7 22.44 87.1 25.2 57.3 24.66 62.8 44.0 45.6 17.98 70915 5584 12.703/15/2004 13:16:50 74.6 2500 53.8 68.2 41.9 16.14 70.9 61.9 53.7 22.41 87.1 24.9 57.2 24.61 62.2 44.0 45.2 17.77 70536 5569 12.673/15/2004 13:17:00 74.6 2500 53.8 68.2 41.9 16.14 70.9 61.9 53.7 22.41 87.2 24.2 57.1 24.55 60.9 44.0 44.3 17.33 70536 5556 12.703/15/2004 13:17:10 74.7 2500 53.8 68.3 41.9 16.14 71.0 61.9 53.7 22.45 87.3 24.9 57.3 24.68 62.4 44.0 45.4 17.84 70959 5548 12.793/15/2004 13:17:20 74.7 2500 53.8 68.4 41.9 16.15 71.0 61.9 53.7 22.45 87.3 24.6 57.3 24.64 61.0 44.1 44.4 17.37 70906 5545 12.793/15/2004 13:17:30 74.7 2500 53.8 68.4 41.9 16.15 70.9 61.8 53.7 22.40 87.3 24.2 57.2 24.58 60.5 44.1 44.1 17.20 70332 5552 12.673/15/2004 13:17:40 74.7 2500 53.9 68.3 42.0 16.18 71.0 61.9 53.7 22.45 87.3 24.0 57.1 24.55 60.3 44.1 43.9 17.13 70551 5571 12.673/15/2004 13:17:50 74.7 2500 53.9 68.3 42.0 16.18 70.9 61.9 53.7 22.41 87.3 25.0 57.4 24.70 62.1 44.1 45.2 17.74 70075 5598 12.523/15/2004 13:18:00 74.7 2500 53.9 68.2 42.0 16.17 71.0 61.9 53.7 22.45 87.3 24.7 57.3 24.66 61.8 44.1 45.0 17.64 70605 5615 12.583/15/2004 13:18:10 74.7 2500 53.9 68.1 42.0 16.17 71.0 61.9 53.7 22.45 87.4 24.3 57.3 24.63 61.1 44.1 44.5 17.40 70658 5626 12.563/15/2004 13:18:20 74.7 2500 53.9 67.9 42.0 16.16 71.0 61.9 53.7 22.45 87.4 24.4 57.3 24.65 61.2 44.1 44.6 17.44 70765 5633 12.563/15/2004 13:18:30 74.8 2500 53.9 68.0 42.0 16.16 71.0 61.9 53.7 22.45 87.5 24.6 57.4 24.71 60.9 44.1 44.4 17.33 70711 5632 12.563/15/2004 13:18:40 74.8 2500 53.9 68.0 42.0 16.16 71.0 61.9 53.7 22.45 87.5 24.2 57.3 24.65 61.0 44.1 44.4 17.37 70711 5615 12.593/15/2004 13:18:50 74.8 2500 53.9 68.1 42.0 16.17 71.0 61.9 53.7 22.45 87.5 24.5 57.4 24.70 60.6 44.1 44.1 17.23 70658 5594 12.633/15/2004 13:19:00 74.8 2500 53.8 68.1 41.9 16.13 71.0 61.9 53.7 22.45 87.5 24.0 57.2 24.62 60.3 44.1 43.9 17.13 71066 5579 12.743/15/2004 13:19:10 74.8 2500 53.9 68.1 42.0 16.17 71.0 61.8 53.7 22.44 87.4 24.4 57.3 24.65 60.7 44.1 44.2 17.27 70560 5561 12.693/15/2004 13:19:20 74.8 2500 53.9 68.2 42.0 16.17 71.0 61.8 53.7 22.44 87.4 24.7 57.3 24.69 60.9 44.1 44.4 17.33 70507 5546 12.713/15/2004 13:19:30 74.7 2500 53.9 68.3 42.0 16.18 71.0 61.9 53.7 22.45 87.4 24.5 57.3 24.66 61.1 44.1 44.5 17.40 70551 5533 12.753/15/2004 13:19:40 74.7 2500 53.9 68.4 42.0 16.18 71.0 61.9 53.7 22.45 87.4 25.0 57.4 24.74 61.5 44.1 44.8 17.54 70498 5543 12.723/15/2004 13:19:50 74.7 2500 53.9 68.5 42.0 16.19 71.0 62.0 53.8 22.46 87.5 24.6 57.4 24.71 61.6 44.1 44.8 17.57 70543 5569 12.673/15/2004 13:20:00 74.7 2500 53.9 68.4 42.0 16.18 71.0 62.0 53.8 22.46 87.5 25.7 57.6 24.88 61.9 44.1 45.0 17.67 70596 5592 12.623/15/2004 13:20:10 74.7 2500 53.9 68.4 42.0 16.18 71.0 61.9 53.7 22.45 87.6 24.9 57.5 24.79 62.1 44.1 45.2 17.74 70498 5617 12.553/15/2004 13:20:20 74.7 2500 53.9 68.3 42.0 16.18 71.0 61.9 53.7 22.45 87.6 24.9 57.5 24.79 62.2 44.1 45.2 17.78 70551 5624 12.543/15/2004 13:20:30 74.7 2500 53.9 68.1 42.0 16.17 71.0 62.0 53.8 22.46 87.6 24.4 57.4 24.72 61.3 44.2 44.6 17.48 70756 5634 12.563/15/2004 13:20:40 74.7 2500 53.9 68.1 42.0 16.17 71.0 62.1 53.8 22.47 87.6 25.1 57.5 24.82 61.8 44.2 45.0 17.65 70854 5636 12.573/15/2004 13:20:50 74.8 2500 53.9 68.1 42.0 16.17 71.0 62.2 53.8 22.48 87.7 25.1 57.6 24.86 63.3 44.2 46.0 18.16 70951 5627 12.613/15/2004 13:21:00 74.7 2500 53.9 68.3 42.0 16.18 71.1 62.3 53.9 22.53 87.7 24.1 57.4 24.71 61.4 44.2 44.7 17.51 71421 5611 12.733/15/2004 13:21:10 74.8 2500 53.9 68.4 42.0 16.18 71.1 62.3 53.9 22.53 87.7 23.5 57.2 24.62 60.0 44.2 43.8 17.04 71368 5594 12.763/15/2004 13:21:20 74.8 2500 53.9 68.5 42.0 16.19 71.1 62.2 53.9 22.52 87.6 23.8 57.2 24.63 60.4 44.2 44.0 17.17 71217 5582 12.763/15/2004 13:21:30 74.7 2500 53.9 68.6 42.0 16.19 71.2 62.2 53.9 22.56 87.6 23.8 57.2 24.63 60.1 44.2 43.8 17.07 71642 5564 12.883/15/2004 13:21:40 74.7 2500 53.9 68.6 42.0 16.19 71.2 62.2 53.9 22.56 87.6 23.6 57.2 24.60 59.8 44.2 43.6 16.97 71642 5552 12.913/15/2004 13:21:50 74.7 2500 53.9 68.6 42.0 16.19 71.2 62.1 53.9 22.55 87.5 23.8 57.2 24.59 59.9 44.2 43.7 17.00 71544 5544 12.913/15/2004 13:22:00 74.7 2500 54.0 68.6 42.1 16.23 71.2 62.0 53.9 22.54 87.5 23.7 57.2 24.58 59.8 44.2 43.6 16.97 71037 5546 12.813/15/2004 13:22:10 74.7 2500 54.0 68.6 42.1 16.23 71.3 62.0 54.0 22.59 87.4 23.7 57.1 24.54 59.8 44.1 43.6 16.96 71516 5558 12.873/15/2004 13:22:20 74.7 2500 54.0 68.5 42.1 16.22 71.3 62.0 54.0 22.59 87.4 23.8 57.1 24.56 59.5 44.2 43.4 16.87 71569 5587 12.813/15/2004 13:22:30 74.7 2500 54.0 68.4 42.1 16.22 71.3 61.9 54.0 22.58 87.3 24.2 57.2 24.58 60.1 44.1 43.8 17.07 71524 5602 12.773/15/2004 13:22:40 74.6 2500 54.1 68.2 42.1 16.25 71.3 61.9 54.0 22.58 87.3 24.5 57.2 24.63 60.5 44.1 44.1 17.20 71223 5615 12.683/15/2004 13:22:50 74.6 2500 54.1 68.1 42.1 16.24 71.3 61.8 53.9 22.57 87.1 24.1 57.0 24.50 60.0 44.1 43.7 17.03 71178 5621 12.663/15/2004 13:23:00 74.7 2500 54.1 68.0 42.1 16.24 71.4 61.8 54.0 22.61 87.0 24.4 57.1 24.50 60.2 44.1 43.9 17.10 71710 5627 12.743/15/2004 13:23:10 74.6 2500 54.1 67.9 42.1 16.23 71.4 61.7 54.0 22.60 87.0 24.5 57.1 24.52 60.4 44.1 44.0 17.17 71665 5624 12.743/15/2004 13:23:20 74.6 2500 54.1 67.8 42.1 16.23 71.4 61.6 54.0 22.59 86.9 24.5 57.0 24.48 60.0 44.1 43.7 17.03 71619 5605 12.783/15/2004 13:23:30 74.6 2500 54.1 67.8 42.1 16.23 71.4 61.6 54.0 22.59 86.9 25.2 57.2 24.59 59.3 44.1 43.3 16.80 71619 5585 12.823/15/2004 13:23:40 74.6 2500 54.1 67.9 42.1 16.23 71.4 61.6 54.0 22.59 86.8 24.9 57.1 24.51 60.4 44.1 44.0 17.17 71566 5572 12.843/15/2004 13:23:50 74.6 2500 54.1 67.9 42.1 16.23 71.4 61.6 54.0 22.59 86.8 24.6 57.0 24.46 60.0 44.1 43.7 17.03 71566 5555 12.883/15/2004 13:24:00 74.6 2500 54.1 67.9 42.1 16.23 71.4 61.5 54.0 22.58 86.7 24.6 56.9 24.43 59.8 44.1 43.6 16.96 71467 5542 12.903/15/2004 13:24:10 74.6 2500 54.1 67.9 42.1 16.23 71.4 61.5 54.0 22.58 86.7 24.7 57.0 24.44 59.7 44.1 43.5 16.93 71467 5531 12.923/15/2004 13:24:20 74.6 2500 54.1 68.0 42.1 16.24 71.4 61.4 54.0 22.58 86.6 24.7 56.9 24.41 59.7 44.1 43.5 16.93 71314 5533 12.893/15/2004 13:24:30 74.6 2500 54.2 68.0 42.2 16.27 71.4 61.4 54.0 22.58 86.5 24.9 56.9 24.40 59.9 44.1 43.7 17.00 70905 5557 12.763/15/2004 13:24:40 74.6 2500 54.2 67.9 42.2 16.27 71.4 61.5 54.0 22.58 86.5 24.9 56.9 24.40 59.9 44.1 43.7 17.00 71059 5586 12.723/15/2004 13:24:50 74.6 2500 54.2 67.9 42.2 16.27 71.4 61.6 54.0 22.59 86.3 24.8 56.8 24.32 60.3 44.0 43.9 17.13 71158 5604 12.70

March 25, 2004 DE-FC26-00NT40991 – HyPak – Final Report Page J-1

Appendix J: LBNL Laboratory Testing Validation Memo

J-2

25 March 2004 To Whom It May Concern: In an effort to provide a third-party assessment of the Davis Energy Group’s HyPak Phase 3

testing effort, I have extensively reviewed their testing procedures, laboratory apparatus, and

monitoring systems, and have found them to be appropriate. I find the attached results (Table 1)

to be an acceptable summary of the laboratory tests. The overall test goal was to establish

laboratory performance of the current (Phase 3) design.

The HyPak unit was tested under 4 conditions: the ARI Standard Rating, Modified ARI

Conditions, Western Summer Conditions, and Western Maximum Conditions. See Table 1 for

definitions of these conditions and results.

HyPak system Energy Efficiency Ratio (EER), defined as the total (sensible plus latent) cooling

of the space and ventilation air (in BTU/hr) divided by the total input power to the HyPak unit

(in Watts), is the applicable performance measure. The results appear sound based on the

measurements using the instrumentation specifications, installation, and procedures that I

reviewed. The uncertainty (worst-case error) in the EER measurements is 16%.

In summary, the data indicate that the overall EER for the HyPak ranges from 14.7 to 18.2 with

the modified condenser/evaporative cooler. It is clear from a run with unmodified cooler (11%

higher EER even with outdoor conditions hotter and wetter than the comparable ARI standard

test) that the unit could be substantially more efficient; in particular, the HyPak

condenser/indirect evaporative cooler section could benefit from further research and

development. The size, efficiency, and ventilation features of the unit should make it an

attractive option for the small and medium commercial building market. The unit’s performance

is promising, especially in hot, dry climates where the evaporative cooling and condensing

J-3

features offer significant performance enhancements. It will be valuable in the future to derive

field data and additional lab data, preferably from an independent laboratory, for additional units.

Sincerely,

Steve Greenberg, Engineer Environmental Energy Technologies Division Lawrence Berkeley National Laboratory 90R3111, 1 Cyclotron Rd Berkeley CA 94720 510-486-6971 [email protected] Table 1. Phase 3 (current design) HyPak testing results completed at Des Champs laboratory, Natural Bridge Station, VA, February 4th and 9th 2004. The first five lines are the intended test conditions, the remainder are the actual conditions and performance. The capacity, and the resultant EER, are based on the difference between the mixed air and the supply air conditions, (since the ventilation air must also be cooled), rather than the return air vs. supply air conditions. Test>> ARI

Standard Conditions

Modified ARI Conditions

Western Summer

Conditions

Western Maximum Conditions

Outdoor Air Dry Bulb, °F, Design 95 95 95 100 Outdoor Air Wet Bulb, °F, Design 75 75 66 70 Return Air Dry Bulb, °F, Design 80 80 76 80 Return Air Wet Bulb, °F, Design 67 67 64 67 Ventilation Air, scfm, Design 0 800 800 800 Total Power, Watts 5480 5510 4970 4960 Supply scfm 2990 2990 3000 2990 Ventilation scfm 0 363 795 744

Return Air Dry Bulb, °F 80.3 79.9 76.6 79.9 Return Air Wet Bulb, °F 65.7 66.0 63.4 65.1 Mixed Air Dry Bulb, °F 80.6 80.4 77.4 80.7 Mixed Air Wet Bulb, °F 66.7 67.2 64.5 66.0 Supply Air Dry Bulb, °F 60.7 61.5 58.7 60.2 Supply Air Wet Bulb, °F 58.4 59.4 56.3 57.9

Capacity, BTU/hr 80,300 81,000 90,300 85,900 EER 14.7 14.7 18.2 17.3

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