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Empire State Building Performance Year 4 M&V Report April 2, 2015
Empire State Building Performance Year 4 M&V Report
Table of Contents i
Table of Contents
Table of Contents .................................................................................................i
1. Executive Summary ....................................................................................... 1
2. Project Overview ............................................................................................ 8
2.1 Project Guaranteed Savings .................................................................... 9
2.2 eQUEST Model Setup Overview ............................................................ 10
Model Build .................................................................................................. 10
3. ECM 1: Window Retrofit ............................................................................. 11
3.1 ECM 1: Window Retrofit ........................................................................ 11
3.1.1 ECM Description ............................................................................... 11
3.1.2 Pre-Installation System Conditions .................................................... 11
3.1.3 Post-Installation System Conditions .................................................. 11
3.1.4 ECM M&V Methodology .................................................................... 12
4. ECM 2: Radiator Insulation and Steam Trap Retrofit ............................... 13
4.1 ECM 2.1: Radiator Insulation ................................................................ 13
4.1.1 ECM Description ............................................................................... 13
4.1.2 Pre-Installation System Conditions .................................................... 13
4.1.3 Post-Installation System Conditions .................................................. 13
4.1.4 ECM M&V Methodology .................................................................... 13
4.2 ECM 2.2: Steam Trap Retrofit ............................................................... 15
4.2.1 ECM Description ............................................................................... 15
4.2.2 Pre-Installation System Conditions .................................................... 15
4.2.3 Post-Installation System Conditions .................................................. 15
4.2.4 ECM M&V Methodology .................................................................... 15
5. ECM 3: BMS Retrofit ................................................................................... 16
5.1 ECM 3.1: BMS Damper Retrofit and DCV............................................. 16
5.1.1 ECM Description ............................................................................... 16
5.1.2 Pre-Installation System Conditions .................................................... 16
5.1.3 Post-Installation System Conditions .................................................. 17
5.1.4 ECM M&V Methodology .................................................................... 17
Empire State Building Performance Year 4 M&V Report
Table of Contents ii
5.2 ECM 3.2: Fan Scheduling ...................................................................... 17
5.2.1 ECM Description ............................................................................... 17
5.2.2 Pre-Installation System Conditions .................................................... 18
5.2.3 Post-Installation System Conditions .................................................. 18
5.2.4 ECM M&V Methodology .................................................................... 18
6. ECM 4: Chiller Plant Retrofit ...................................................................... 19
6.1 ECM 4.1: Chiller Tubes and Chiller VFD Retrofit ................................ 19
6.1.1 ECM Description ............................................................................... 19
6.1.2 Pre-Installation System Conditions .................................................... 20
6.1.3 Post-Installation System Conditions .................................................. 20
6.1.4 ECM M&V Methodology .................................................................... 20
6.2 ECM 4.2: CHW Supply Temperature Reset .......................................... 21
6.2.1 ECM Description ............................................................................... 21
6.2.2 Pre-Installation System Conditions .................................................... 21
6.2.3 Post-Installation System Conditions .................................................. 21
6.2.4 ECM M&V Methodology .................................................................... 22
6.3 ECM 4.3: CHW Loop Delta-T Enhancement ......................................... 22
6.3.1 ECM Description ............................................................................... 22
6.3.2 Pre-Installation System Conditions .................................................... 23
6.3.3 Post-Installation System Conditions .................................................. 23
6.3.4 ECM M&V Methodology .................................................................... 23
6.4 ECM 4.4: CHW Pump VFD Automation ................................................ 24
6.4.1 ECM Description ............................................................................... 24
6.4.2 Pre-Installation System Conditions .................................................... 25
6.4.3 Post-Installation System Conditions .................................................. 25
6.4.4 ECM M&V Methodology .................................................................... 26
6.5 ECM 4.5: Condenser Water Supply Temperature Reset .................... 26
6.5.1 ECM Description ............................................................................... 26
6.5.2 Pre-Installation System Conditions .................................................... 27
6.5.3 Post-Installation System Conditions .................................................. 27
6.5.4 ECM M&V Methodology .................................................................... 27
6.6 ECM 4.6: Cooling Tower Fan VFD Automation ................................... 28
6.6.1 ECM Description ............................................................................... 28
6.6.2 Pre-Installation System Conditions .................................................... 29
6.6.3 Post-Installation System Conditions .................................................. 29
6.6.4 ECM M&V Methodology .................................................................... 29
Empire State Building Performance Year 4 M&V Report
Table of Contents iii
6.7 ECM 4.7: CW Pump VFD Automation .................................................. 30
6.7.1 ECM Description ............................................................................... 30
6.7.2 Pre-Installation System Conditions .................................................... 31
6.7.3 Post-Installation System Conditions .................................................. 31
6.7.4 ECM M&V Methodology .................................................................... 31
7. ECM 5: Tenant Energy Management Portal .............................................. 32
7.1 ECM 5: TEM Portal ................................................................................. 32
7.1.1 ECM Description ............................................................................... 32
7.1.2 Pre-Installation System Conditions .................................................... 32
7.1.3 Post-Installation System Conditions .................................................. 33
7.1.4 ECM M&V Methodology .................................................................... 33
8. ECM 6: Low Zone and Mid Zone PFHX ..................................................... 34
8.1 ECM 6: Low Zone and Mid Zone PFHX ................................................ 34
8.1.1 ECM Description ............................................................................... 34
8.1.2 Pre-Installation System Conditions .................................................... 34
8.1.3 Post-Installation System Conditions .................................................. 34
8.1.4 ECM M&V Methodology .................................................................... 34
Appendix List .................................................................................................... 35
Appendix 1: BMS Retrofit Data Analysis .................................................... 36
Damper Retrofit and DCV ............................................................................ 36
Fan Scheduling ............................................................................................ 39
Mid Zone/High Zone AHU Supply Fan Scheduling ...................................... 39
Appendix 2: Chiller Retrofit Data Analysis ................................................. 45
Chiller Curve Fit Modeling Methodology ...................................................... 45
Low Zone Chiller-1 Performance Curves ..................................................... 47
Mid Zone Chiller-4 Performance Curves ...................................................... 49
Mid Zone Chiller-5 Performance Curves ...................................................... 51
High Zone Chiller-6 Performance Curves..................................................... 53
Appendix 3: Chiller Plant Retrofit Data Analysis ....................................... 55
CHWST Reset .............................................................................................. 55
CHW Loop Delta-T Enhancement ................................................................ 57
CHW Pump VFD Automation ....................................................................... 58
CW Supply Temperature Reset ................................................................... 59
Cooling Tower Fan VFD Automation ............................................................ 60
CW Pump VFD Automation .......................................................................... 61
Appendix 4: PFHX Data Analysis ................................................................ 62
Empire State Building Performance Year 4 M&V Report
Table of Contents iv
Appendix 5: ESB eQUEST Model Inputs .................................................... 65
Appendix 6: Baseline Adjustments ............................................................. 69
List of 2014 Baseline Adjustments ............................................................... 69
Weather Data ............................................................................................... 69
Utility Analysis .............................................................................................. 69
Construction Floor Data ............................................................................... 69
Construction Floor Space Temperature Analysis ......................................... 70
Tenant Vacancy Analysis ............................................................................. 70
Tenant Space Temperature Analysis ........................................................... 74
Broadcast Floors Electric Load Data ............................................................ 74
VAV AHU Upgrades ..................................................................................... 75
Appendix 7: ESB Utility Rates ..................................................................... 76
Glossary ............................................................................................................ 78
Report Delivery Acknowledgement ................................................................. 80
Empire State Building Performance Year 4 M&V Report
Section 1 - Executive Summary 1
1.
Empire State Building (ESB) has committed to a major sustainability retrofit in order to become a leading example of economic and environmental revitalization. A Johnson Controls Energy Performance Contract (EPC) was undertaken to install five Energy Conservation Measures (ECM) of the Sustainability Program at ESB. In addition, a Plate and Frame Heat Exchanger (PFHX) ECM was installed in 2013 as part of a change order to the original EPC. This report documents the project savings in Performance Year (PY) 2014.
Annual savings for all ECMs are calculated based on International Performance Measurement and Verification Protocol (IPMVP) Option D, which utilizes building performance simulation software (eQUEST®). However, the steam trap savings were contractually agreed to be non-measured savings and the PFHX savings are directly derived from measurements.
Figure 1.1 shows the Contract Guaranteed savings, the PY Target Guaranteed savings, the PY ECM Performance savings, the PY Actual Operation savings and the PY Actual Utility savings. Johnson Controls savings guarantee obligation is evaluated by comparing total PY ECM Performance savings with total PY Target Guaranteed savings. The total PY ECM Performance savings exceeded the PY Target Guaranteed savings for the 2014 period. Not all PY ECM Performance savings are captured in ESB’s actual utility bills due to ECM field operation deviations from design. PY Actual Utility savings reflect the savings seen on the actual utility bills.
Empire State Building Performance Year 4 M&V Report
Section 1 - Executive Summary 2
No. ECM
Contract Guaranteed
Savings1
(Unadjusted, from Contract)
PY Target Guaranteed
Savings2 (Using 2014
Baseline Adjustments)
PY ECM Performance
Savings3 (Using 2014
Measurements)
PY Actual Operation Savings4
(Using 2014 Actual Operations Data)
PY Actual Utility Savings5
(Using 2014 Actual Utility Rates)
[A] [B] [C] [D] [E] [F] [G]
1 Windows Retrofit $338,508 $370,112 $275,104 $275,104 $282,694
2 Radiator Insulation and Steam Traps
$491,191 $523,450 $627,710 $627,710 $617,835
3 BMS Retrofit $774,388 $886,453 $1,090,078 $1,090,078 $1,015,826
4 Chiller Plant Retrofit6 $611,641 $650,157 $867,700 $838,887 $764,703
5 Tenant Energy Management
$25,000 $27,334 $0 $0 $0
6 PFHX7 $133,607 $202,899 $202,899 $202,899 $186,676
Total $2,374,335 $2,660,405 $3,063,491 $3,034,678 $2,867,734
Note:
1. Contract Guaranteed savings were calculated using the 2007 Baseline and 2007 utility rates. Johnson Controls guaranteed 90.6% of the modeled contract savings for all ECMs except steam traps, TEM and PFHX.
2. PY Target Guaranteed savings were calculated by making 2014 Baseline adjustments to the 2007 Contract Guaranteed savings model and using 3.02% annually escalated contract utility rate, escalation starting from PY2 (called the “PY contract utility rate”).
3. PY ECM Performance savings were calculated by inputting measurements of 2014 ECM performance to the PY Target Guaranteed savings model and using PY contract utility rate.
4. In certain cases, the ECM equipment was operated to accommodate building operational necessities and not as programmed. Operations data accounts for such changes in ECM operation (see Appendix 3 for details). PY Actual Operation savings were calculated by inputting 2014 operations data to the PY ECM Performance savings model and using PY contract utility rate.
5. PY Actual Utility savings were calculated by inputting 2014 actual utility rates into the PY Actual Operation savings model.
6. The Chiller Plant Retrofit savings numbers from the eQuest model includes the PFHX savings during the shoulder season. The Chiller Plant Retrofit savings numbers shown here are adjusted using PFHX shoulder season savings numbers to avoid double accounting.
7. The PFHX ‘Contract Guaranteed Savings’ uses 2011 energy usage as the baseline and uses the original contract rate (2007 utility rate with annual escalation) for utility rates. The PFHX ‘PY Target Guaranteed Savings’ uses 2014 energy usage as the adjusted baseline and uses the original contract rate (2007 utility rate with annual escalation) for utility rates..
Figure 1.1: 2014 Project Savings
ECM performance accounts for the following:
The window testing is conducted every two years. The latest test was conducted in 2013. The measured performance of the windows outperformed the target (see Section 3 for details). But, ECM performance savings are still lower than the target savings because Johnson Controls is upholding a higher target that was incorrectly calculated at the time of contract.
Empire State Building Performance Year 4 M&V Report
Section 1 - Executive Summary 3
The one time measurement of radiator insulation thermal resistance (tested in 2010) showed that the Radiator Insulation ECM is projected to outperform contract savings for all Performance Periods (see Section 4 for details).
Steam trap surveying is used to identify leaking or failed traps. However, they are contracted to be non-measured savings. The latest survey was conducted in March 2013. The survey results were published in 2013 Q1 report.
Trending analysis for 2014 indicated that the ECM savings for the Building Management System (BMS) retrofit exceeds target savings in PY4.
Trending analysis for 2014 indicated that the savings for the Chiller Plant Retrofit ECM exceeds contracted savings in PY4. In certain cases, the mechanical equipment was operated to accommodate building operational necessities and not as programmed (see Appendix 3 for details). PY Actual Operation savings reflect the savings in the actual field operation scenario using PY contract utility rates. PY Actual Utility savings reflect the savings in the actual field operation scenario using PY actual utility rates.
ESB and Johnson Controls agreed to not claim Tenant Energy Management (TEM) savings in 2014 because of Tenant submeter inaccuracy issues. Majority of the issues are currently resolved.
2014 trending analysis indicated that the PFHX is operating within the contract performance specifications and the ECM performance savings meets the target savings.
Figure 1.2 illustrates that ESB’s Post-Installation electric utility consumption was reduced by 29% during base load conditions and was reduced by at least 33% during the hottest month.
Empire State Building Performance Year 4 M&V Report
Section 1 - Executive Summary 4
Figure 1.2: Reduction in ESB’s Baseline Electric Utility Consumption
during Performance Periods
Figure 1.3 illustrates reduction in ESB’s Baseline electric demand. The relative increase in 2014 demand is attributed to the escalation in summer electric chiller usage and building tenant occupancy. Summer electric chiller usage increase was a direct result of the change in ESB’s 2014 chiller operation, which was changed from steam chiller primary to electric chiller primary; a transformation recommended by Johnson Controls. As a result of this modification, ESB significantly benefitted with increase in revenues as shown below.
Decrease in summer steam cost as illustrated by Figure 1.4, which led to decrease in total utility cost.
In addition to the decrease in total utility cost, the shift to electric chiller primary resulted in a larger Demand Response scope and therefore higher Demand Response revenue.
Empire State Building Performance Year 4 M&V Report
Section 1 - Executive Summary 5
Figure 1.3: Reduction in ESB’s Baseline Electric Utility Consumption and Demand
during Performance Periods
Figure 1.4: Reduction in ESB’s Baseline Summer Steam Utility Consumption
during Performance Periods
Empire State Building Performance Year 4 M&V Report
Section 1 - Executive Summary 6
Figure 1.5 illustrates ESB’s winter steam consumption change with heating degree days. Increased occupancy and construction activities lead to increase in the winter steam usage.
Figure 1.5: Reduction in ESB’s 2007 Baseline Winter Steam Utility Consumption
during Performance Period
Figure 1.6 illustrates that ESB’s unadjusted total utility costs have decreased significantly.
2014 total utility costs are reduced by 40% when compared with the 2007 Baseline.
2014 total electric costs are reduced by 45% when compared with the 2007 Baseline and the consumption is reduced by 25% during the same period.
2014 steam costs are reduced by 16% when compared with the 2007 Baseline and the consumption is reduced by 10% during the same period.
The unadjusted actual utility cost reductions shown in Figure 1.6 reflect energy savings due to various factors including installation of Johnson Controls ECMs.
Empire State Building Performance Year 4 M&V Report
Section 1 - Executive Summary 7
Figure 1.6: Reduction in ESB’s Unadjusted Baseline Utility Costs
during Performance Period
Empire State Building Performance Year 4 M&V Report
Section 2 - Project Overview 8
2.
Johnson Controls developed an EPC to install five ECMs of the Sustainability Program at ESB. The EPC consolidated the balance of Direct Digital Control (DDC) and Demand Control Ventilation (DCV) measures into one BMS Retrofit ECM. In addition, a PFHX ECM was installed in 2013 as part of a change order to the original EPC. Therefore, a total of six measures have been documented in the EPC. The contract-guaranteed savings for each ECM is listed in Figure 2.1.
No. ECM Electric kWh
Savings Electric kW
Savings Steam Mlb
Savings
Unadjusted Year 1 Contract Guaranteed
Savings
[A] [B] [C] [D] [E] [F]
1 Windows Retrofit 1,329,797 116 5,115 $338,508
2 Radiator Insulation and Steam Traps
14,870 $491,191
3 BMS Retrofit 1,621,091 138 16,744 $774,388
4 Chiller Plant Retrofit 2,963,656 1,095 824 $611,641
5 Tenant Energy Management 160,256
$25,000
6 PFHX 1,100,725 $133,607
Total 7,175,525 1,349 37,553 $2,374,335
Figure 2.1: Shows the contract savings in kWh, kW, Mlb and total unadjusted guaranteed savings for each ECM
Empire State Building Performance Year 4 M&V Report
Section 2 - Project Overview 9
2.1
Figure 2.2 shows the unadjusted project guaranteed savings for the 15-year guarantee period.
Year
Total Unadjusted Guaranteed
Savings
Windows Retrofit
Radiator Insulation/Steam
Traps Retrofit
Chiller Plant Retrofit
BMS Retrofit TEM PFHX
[A] [B] [C] [D] [E] [F] [G] [H]
1 $2,240,728 $338,508 $491,191 $611,641 $774,388 $25,000 $0
2 $2,310,490 $348,731 $506,025 $630,113 $799,866 $25,755 $0
3 $2,382,428 $359,263 $521,307 $649,142 $826,183 $26,533 $0
4 $2,590,214 $370,112 $537,050 $668,746 $853,365 $27,334 $133,607
5 $2,670,744 $381,290 $553,269 $688,942 $881,441 $28,160 $137,642
6 $2,753,782 $392,805 $569,978 $709,748 $910,442 $29,010 $141,799
7 $2,839,404 $404,667 $587,191 $731,183 $940,396 $29,886 $146,081
8 $2,927,695 $416,888 $604,925 $753,264 $971,336 $30,789 $150,493
9 $3,018,734 $429,478 $623,193 $776,013 $1,003,294 $31,718 $155,038
10 $3,112,611 $442,449 $642,014 $799,449 $1,036,303 $32,676 $159,720
11 $3,209,411 $455,811 $661,403 $823,592 $1,070,399 $33,663 $164,543
12 $3,309,225 $469,576 $681,377 $848,464 $1,105,616 $34,680 $169,512
13 $3,412,150 $483,757 $701,954 $874,088 $1,141,992 $35,727 $174,632
14 $3,518,282 $498,367 $723,154 $900,485 $1,179,564 $36,806 $179,906
15 $3,627,720 $513,417 $744,993 $927,680 $1,218,373 $37,918 $185,339
Total $43,923,616 $6,305,119 $9,149,024 $11,392,550 $14,712,958 $465,655 $1,898,310
Figure 2.2: Unadjusted Project Guaranteed Savings
Note: The savings for each year is annually escalated by 3.02% from the baseline year.
Empire State Building Performance Year 4 M&V Report
Section 2 - Project Overview 10
2.2
Modeling Software
eQUEST v3.64 with patch
Model Author
Quest Energy Group, LLC 1620 W Fountainhead Pkwy #303 Tempe, AZ 85282 +1 480 467 2480
Model Build
A detailed architectural model of the building was created from detailed analysis of archive drawings, photos taken on-site and thorough inspections verifying wall and roof constructions, external shading, and glass types.
Schedules, based on building operation, were also employed in the model to simulate real-world conditions.
Lighting demand and energy (schedules) were calculated into the model based upon the lighting information provided by JLL.
Representative internal equipment loads, by space type (office, corridor, etc.), were incorporated into the model.
Heating, Ventilating, and Air-Conditioning (HVAC) equipment, including their demonstrated efficiencies, were added to the model with each zone being assigned to the appropriate HVAC system. Zoning was determined by the base building core areas including elevator shafts, restrooms, corridors, etc. and the tenant occupy-able areas, which were zoned using perimeter/core areas by orientation. HVAC equipment efficiencies were based on field measurements, nameplate data, or mechanical plans as available (this method dovetails into your report's description of field measured data, etc.).
Vacancy rates for the building were included in the model.
The contract model eQUEST version did not have the capability to model individual ESB floors. There have been improvements in eQUEST software which enabled Quest Energy Group to model individual ESB floors.
Empire State Building Performance Year 4 M&V Report
Section 3 - ECM 1: Window Retrofit 11
3.
The savings numbers associated with the window retrofit is shown below:
PY Target Performance savings was calculated to be $370,112 by using PY Adjusted Baseline and by using Contract Target Performance.
PY ECM Performance savings was calculated to be $275,104 by using PY Adjusted Baseline and by using 2013 measurements.
PY Actual Operation savings was calculated to be $275,104 by using PY Adjusted Baseline and by using 2013 measurements.
3.1
3.1.1
The window retrofit ECM served to upgrade the existing Insulated Glass (IG) for 6,514 double-hung windows by adding suspended coated film Alpen glass. The required re-manufacturing of the (2 x 6,514 =) 13,028 IG units was conducted on-site at ESB. IG units were removed and moved to a production area located on the 5th Floor. Either Alpen glass TC88 or SC75 was used as the suspended film depending upon window orientation. A mixture of krypton/argon gas was used to fill the window glass chamber. This ECM improved the thermal resistance of the glass and reduced solar heat gain values. As an additional contribution to sustainability, glass removed from the windows was recycled.
3.1.2
Pre-Installation double pane windows were estimated (not measured at that time) to have 0.48 U-Value and 0.645 Solar Heat Gain Coefficient (SHGC). After testing, it was found that Pre-Installation window performance was 0.58 in U-Value and that calculated savings would exceed estimated savings.
3.1.3
North windows were targeted to attain 0.365 U-Value and 0.448 SHGC through Krypton/Argon gas fill and TC88 suspended film. S-E-W windows were targeted to attain 0.384 U-Value and 0.325 SHGC through Krypton gas fill and SC75 suspended film. The Post-Installation north facing windows were tested in 2013 to attain ECM Performance values shown in Figure 3.2. The next windows test is due by December 2015.
Empire State Building Performance Year 4 M&V Report
Section 3 - ECM 1: Window Retrofit 12
3.1.4
IG units were sent to an independent testing agency (Architectural Testing, Inc. [ATI]) for evaluation of several window performance indices including the ones used as eQUEST inputs (Whole window U-Value and SHGC).
ATI, located in York, PA, is a premier window testing company boasting extensive experience and testing in the field of window testing. ATI is accredited with several agencies including the National Fenestration Rating Council (NFRC), American National Standards Institute, Insulating Glass Certification Council, American Architectural Manufacturers Association, Window and the Door Manufacturers Association. Comprehensive information about ATI, ATI’s work, testing facility and certificate of accreditations is given in the attached test report. A total of four old windows and six new windows were tested for performance.
IG unit performance was tested in accordance with NFRC 102-2010 in a thermal test chamber. The two sides of the chamber were simulated for standard exterior (-0.4˚F at 15mph wind speed) and interior (70˚F) environment. Interior conditions were maintained using an electric heater, the output of which can be measured. IG unit U-factor was calculated using measured heat loss and delta-T.
Whole window (IG unit and frame) performance was evaluated using a combination of gas fill test and industry standard computer simulation. Gas fill tests were performed using a standard gas chromatograph device.
SHGC tests were performed using a window energy profiler device (WP4500) that measures ultraviolet, visible light, infrared transmission values and SHGC. Results from the testing were used to generate the following eQUEST Model inputs that determine the ECM savings.
Contract Baseline
PY Adjusted Baseline
PY Target Performance
PY ECM Performance
PY Actual Operation
North Windows 0.48 / 0.645 0.58 / 0.645 0.365 / 0.448 0.274 / 0.39 0.274 / 0.39
East Windows 0.48 / 0.645 0.58 / 0.645 0.384 / 0.325 0.320 / 0.27 0.320 / 0.27
South Windows 0.48 / 0.645 0.58 / 0.645 0.384 / 0.325 0.337 / 0.27 0.337 / 0.27
West Windows 0.48 / 0.645 0.58 / 0.645 0.384 / 0.325 0.324 / 0.27 0.324 / 0.27
Figure 3.2: Windows ECM Model Inputs (shown as U-value / SHGC)
Figure 3.1: ESB Windows when tested at ATI (left); Schematic of ATI’s window testing chamber (right)
Empire State Building Performance Year 4 M&V Report
Section 4 - ECM 2: Radiator Insulation and Steam Trap Retrofit 13
4.
The savings numbers associated with radiator insulation and steam trap retrofit is shown below:
PY Target Performance savings was calculated to be $523,450 by using PY Adjusted Baseline and by using Contract Target Performance.
PY ECM Performance savings was calculated to be $627,710 by using PY Adjusted Baseline and 2010 measurements.
PY Actual Operation savings was calculated to be $627,710 by using PY Adjusted Baseline and by using 2010 measurements.
4.1
4.1.1
The Radiator Insulation ECM involved the installation of 6,514 insulated reflective barriers behind radiator units located on the perimeter of the building. In addition, the unit itself was cleaned and the thermostat repositioned to the front side of the unit. The reduction of thermal heat loss through the exterior building wall, as a result of installing the reflective barriers, results in measurable energy savings.
4.1.2
Pre-Installation “wall+no-insulation” U-Value was estimated to be 0.209. Post-Installation "wall+insulation" U-Value was estimated to be 0.122. All radiator insulation in the building perimeter wall reduces heat loss.
4.1.3
Radiator insulation was installed in the perimeter wall. Johnson Controls was unable to install the barriers in broadcasting spaces because those spaces were overheating resulting in the radiator assemblies being removed. But, there will be additional savings beyond those that the tests demonstrated due to the reflective layer on the insulation.
4.1.4
Radiator insulation boards were sent to ATI, an independent testing agency, for a one-time measurement of thermal performance.
ATI, located in York, PA, is a fenestration testing company with extensive experience in the field of fenestration testing. ATI is accredited by several agencies; including National Fenestration Rating Council, American National Standards Institute, Insulating Glass Certification Council, American Architectural Manufacturers Association and the Window and Door Manufacturers Association. Comprehensive information about ATI, ATI’s work, testing facility and certificate of accreditations is detailed in the attached test report.
Empire State Building Performance Year 4 M&V Report
Section 4 - ECM 2: Radiator Insulation and Steam Trap Retrofit 14
A total of ten radiator insulation locations were tested for performance.
Figure 4.1: Insulation Testing Equipment at ATI
Radiator Insulation was tested using American Society for Testing and Materials (ASTM) C 518, Standard Test Methodology for Steady State Heat Flux Measurements and Thermal Transmission Properties by Means of Heat Flow Meter Apparatus. The test method includes the measurement of steady state thermal transmission through flat specimens using a heat flow meter apparatus which is a comparative method of measurement that was calibrated to a specimen traceable to National Institute of Materials supplied material.
The cold plate was maintained at a nominal 50˚F and the hot plate was maintained at a nominal 100˚F. A heat flux transducer was introduced on the warm side. Insulation U-factor was calculated using measured heat loss and delta-T.
Results from the testing were used to generate the following eQUEST Model inputs that determine the ECM savings.
Contract Baseline
PY Adjusted Baseline
PY Target PY ECM
Performance PY Actual Operation
Radiative Wall U-Value 0.209 0.209 0.122 0.102 0.102
Figure 4.2: Radiator Insulation ECM Model Inputs
Empire State Building Performance Year 4 M&V Report
Section 4 - ECM 2: Radiator Insulation and Steam Trap Retrofit 15
4.2
4.2.1
Steam traps are designed to prevent steam from passing beyond its point of use and to allow condensate to be expelled as soon as it forms. The traps perform a function similar to that of automatic valves. Steam traps open, close or modulate automatically. Over time, internal parts of steam traps wear out and result in failure to open and close properly. Open traps typically result in loss of live steam, while a closed trap may result in loss of heat transfer to the area and possible water hammering. Water hammering can eventually damage the valves and other components in steam systems, a condition that could result in steam leaks.
All ESB steam radiators are fitted with thermostatic steam traps which incorporate a diaphragm or bellows, comprising a volatile liquid, sealed under vacuum. The trap opens and closes in a modulating manner dependent upon the temperature affecting it. The trap’s normal state is wide open to expel air and condensate. When surrounded by steam at saturated temperature, the volatile fill flashes, creating an internal pressure equal to the surrounding pressure. Equalization of pressures allows the bellows to expand to their natural length or closed position, preventing steam from passing. The presence of condensate sufficiently cools the bellows to condense the vapor within. Once again, the external pressure is greater and the bellows reverts back to its contracted, or open position, allowing the condensate to drain from the trap, permitting more steam to enter the radiator, thus modulating action of the trap.
Failure of a Pre-Installation steam trap at ESB could result in steam loss or equipment operational issues. Retrofitting all of the steam traps has greatly reduced steam wastage in the structure.
4.2.2
All of the steam radiators at ESB are fitted with thermostatic steam traps to prevent Pre-Installation traps from failing at ESB.
4.2.3
As part of the performance contract, all radiator steam traps were retrofitted.
4.2.4
The non-measured savings for this ECM is contingent upon the successful installation of the steam traps. Johnson Controls’ energy savings calculation showed an annual steam savings of $520,180 at the time of contract. Johnson Controls was conservative in discounting the projected savings by 38.5% and in guaranteeing $320,000 (equivalent to 9,786 Mlb in eQUEST Model). The PY guaranteed savings are annually escalated by 3.02%.
Empire State Building Performance Year 4 M&V Report
Section 5 - ECM 3: BMS Retrofit 16
5.
The savings numbers associated with the BMS retrofit is shown below:
PY Target Performance savings was calculated to be $886,453 by using PY Adjusted Baseline and by using Contract Target Performance.
PY ECM Performance savings was calculated to be $1,090,078 by using PY Adjusted Baseline and by using 2014 measurements.
PY Actual Operation savings was calculated to be $1,090,078 by using PY Adjusted Baseline and by using 2014 measurements.
5.1
5.1.1
Prior to retrofit, sample spaces were tested disclosing the building’s overall outside air intake was 0.25 cfm/sf. The goal of the ECM was to reduce the building’s overall outside air intake by retrofitting the non-Alerton Air-Handling Unit (AHU) with DCV and modulating dampers. Johnson Controls used American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE) calculations to estimate that the minimum outside air ventilation requirement is 0.12 cfm/SF for an office building with 7 persons per 1,000 SF. Minimum outside air ventilation is possible when CO2 based DCV is combined with the ability to open dampers just enough to satisfy the ventilation demand. This cannot be achieved with the old two-position dampers, but can be achieved with CO2-based DCV controls and modulating dampers.
Demand-controlled operation is used to modulate outside air ventilation based on real-time occupancy. DCV reduces unnecessary over-ventilation that may occur when existing AHUs are programmed to provide ventilation for a maximum assumed occupancy. DCV saves energy while ensuring that ASHRAE Standard 62 ventilation rates are maintained at all times. Johnson Controls retrofitted non-Alerton AHUs with CO2 sensors on the return air duct. DCV was programmed for outside air activation at 800 ppm return air CO2 threshold.
Johnson Controls retrofitted non-Alerton AHU units by replacing their two-position pneumatic damper system with new dampers (if broken), new actuators and DDC controls. The new damper system has the capability to modulate between 0% to 100% open/close positions. In the DCV mode, the dampers linearly modulate between 10% to 100% open position in response to return air CO2 levels between 800 ppm and 1000 ppm.
Reducing outside air intake reduces the load on the building’s HVAC system and generates energy savings.
5.1.2
Prior to the retrofit, non-Alerton AHUs in the building were equipped with pneumatic dampers and actuators exhibiting no DCV. Sample spaces were tested and it was found that the building’s average outside air intake was 0.25 cfm/SF.
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Section 5 - ECM 3: BMS Retrofit 17
5.1.3
Johnson Controls retrofitted non-Alerton AHUs with CO2 sensors on the return air duct. DCV was programmed for outside air activation at 800 ppm ‘return air CO2’ threshold. Johnson Controls also installed the new DDC damper system that is maintained at 10% minimum open position when the outside air temperature is higher than 68°F. During other times, the damper modulates in accordance with the supply valve position. Controls were programmed so that the DCV takes precedence over temperature-based damper control when return air CO2 reaches threshold.
5.1.4
The performance contract required that Johnson Controls retrofit the two-position pneumatic damper system in non-Alerton AHU units with new dampers (if broken), new actuators, DCV and DDC controls (ECM Target).
The new dampers, new actuators, DCV and DDC controls were verified to be operational (ECM Performance).
The new dampers, new actuators, DCV and DDC controls were operated in the field as designed (Actual Operation).
The analyzed plots are presented in Appendix 1. The data for the analysis was retrieved from the Metasys® trend repository and from Facility Performance Indexing‘s (FPI) trend archive. Results from the trending analysis were used to generate the following eQUEST Model inputs that determine the ECM savings.
Contract Baseline
PY Adjusted Baseline
PY Target PY ECM
Performance PY Actual Operation
Outside Air Flow Rate (cfm/sf) 0.25 0.25 0.12 0.12 0.12
Figure 5.1: BMS Retrofit ECM Model Inputs
5.2
5.2.1
The building utilizes fans to provide AHU supply air, exhaust toilet space air and to exhaust building space air. Prior to the performance contract, these fans were manually turned On/Off and did not have DDC controls to automatically schedule On/Off. Johnson Controls installed DDC controls on the AHU fans to automatically schedule On/Off. The reduced fan run time resulted in:
Reduced fan motor electric power consumption
Reduced outside air intake, thereby reducing the need to condition it
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Section 5 - ECM 3: BMS Retrofit 18
As part of the BMS retrofit, all non-Alerton AHUs were connected to the newly-installed Johnson Controls field controllers. These field controllers communicate with Network Automation Engines (NAEs) that tie into ESB’s central Application and Data Server (ADX). ESB’s Metasys operator workstation allows building operations personnel to program, monitor and change HVAC schedules.
5.2.2
Prior to the performance contract, the fans did not have DDC controls to automatically schedule On/Off. The fans were manually turned On/Off. The following table shows the manually operated Pre-Installation schedule.
Fan Type Manually Operated
Pre-Installation ON Time
AHU Supply Fan (Mid Zone and High Zone) 18hrs/5d (ON-Time)
General Exhaust and Toilet Exhaust Fans 24hrs/7d (ON-Time)
Figure 5.2: Pre-Installation Schedule
5.2.3
As part of the BMS retrofit, all non-Alerton AHU supply fans were connected to BMS and the scheduling feature was enabled. The following table shows the Post-Installation conditions.
Fan Type Automatically Scheduled Post-Installation ON Time
(Target)
Automatically Scheduled Post-Installation ON Time (ECM Performance)
AHU Supply Fan (Mid Zone and High Zone) 15hrs/5d (ON-Time) 13.8hrs/5d (ON-Time)
General Exhaust and Toilet Exhaust Fans 19hrs/7d (ON-Time) 20.1hrs/7d (ON-Time)
Figure 5.3: Post-Installation Target and ECM Performance Schedule
5.2.4
The data for the analysis was retrieved from Metasys scheduling BMS page, Metasys trend repository and from FPI’s trend archive. The analyzed information is presented in this Report’s Appendix. Results from the BMS analysis were used to generate the following eQUEST Model inputs that determine the ECM savings.
Contract Baseline
PY Adjusted Baseline
PY Target PY ECM
Performance PY Actual Operation
High/Mid Fans 18hrs/5d
(ON-Time) 18hrs/5d
(ON-Time) 15hrs/5d
(ON-Time) 13.8hrs/5d (ON-Time)
13.8hrs/5d (ON-Time)
General Exhaust and Toilet Exhaust Fans
24hrs/7d (ON-Time)
24hrs/7d (ON-Time)
19hrs/7d (ON-Time)
20.1hrs/7d (ON-Time)
20.1hrs/7d (ON-Time)
Figure 5.4: Fan Scheduling ECM Model Inputs
Empire State Building Performance Year 4 M&V Report
Section 6 - ECM 4: Chiller Plant Retrofit 19
6.
The savings numbers associated with the chiller plant retrofit is shown below:
PY Target Performance savings was calculated to be $694,795 by using PY Adjusted Baseline and by using Contract Target Performance.
PY ECM Performance savings was calculated to be $912,338 by using PY Adjusted Baseline and by using performance programmed in the chiller controls.
PY Actual Operation savings was calculated to be $883,525 by using PY Adjusted Baseline and by using 2014 measurements.
6.1
6.1.1
There were four constant-speed electric chillers previously installed at ESB. This ECM provided for a retrofit of these chiller compressors with Variable Frequency Drives (VFD) and replaced chiller tubes.
1.1.. Chiller VFD Retrofit
A constant-speed chiller reacts to lower load or lower entering-condenser-water temperature by closing its pre-rotation vanes, which throttles the refrigerant flow through the compressor in an effort to economize the energy consumption. As the vanes continue to close, they create frictional losses that affect the chiller’s efficiency and limit the energy-saving potential of this approach.
Use of a VFD allows the compressor speed to modulate in response to load, evaporator pressure, and condenser pressure. Despite the small power penalty attributed to the VFDs, this control measure for the chiller yields outstanding overall efficiency improvement. Most chillers operate at part-load nearly 99% of the time which serves to enhance the overall value of this retrofit. Additionally, the soft start feature, provided by the VFD, provides further maintenance-related value by incurring less stress on the compressor motor, gears and electrical components than does a traditional motor starter.
With its patented Adaptive Capacity Control, the VFD drive learns and remembers optimum speeds for various load and operational conditions. Unlike constant-speed chillers, a variable-speed chiller also maintains a stable power factor.
1.1.. Chiller Tubes Retrofit
Pre-Installation chillers at ESB were about 18 years old. The evaporator and condenser tubes were significantly degraded over time, thereby increasing the fouling factor of the tubes which impedes heat transfer, which, in turn, negatively impacts chiller capacity and efficiency. Johnson Controls replaced the evaporator and condenser tubes with new tubes, thereby increasing chiller capacity, efficiency and service life.
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Section 6 - ECM 4: Chiller Plant Retrofit 20
6.1.2
There were four constant speed electric chillers in the building. The evaporator and condenser tubes were 18 years old and were significantly fouled over time.
6.1.3
All four of the constant-speed electric chillers in the building were retrofitted with VFDs. Johnson Controls also replaced the fouled evaporator and condenser tubes with new tubes.
6.1.4
Department of Energy (DOE) electric chiller curves, available in eQUEST, were used to simulate target performance. The curves were customized for ESB by adjusting them for York-prescribed full-load performance at Air-Conditioning and Refrigeration Institute (ARI) conditions 100% load at 44°F Chilled Water (CHW) temperatures and 85°F Condenser Water (CW) temperatures (ECM Target).
Post-Installation chiller efficiency (kw/ton) was measured at the following conditions (ECM Performance):
Load conditions: 100%, 75%, 50% and 25%
CHW temperatures: 42°F, 44°F and 46°F
CW temperatures: 65°F, 75°F and 85°F
In the case of the chiller retrofit ECM, the ECM Performance represents and Actual Operation. The data analysis is presented in Appendix 2. The data for the analysis was retrieved from the Metasys trend repository and from FPI’s trend archive.
The following eQUEST Model inputs were used to determine the ECM savings.
Contract Baseline PY Adjusted Baseline PY Target PY ECM Performance PY Actual Operation
Chiller-1 (Elec) Capacity
750 Ton (Constant Speed)
750 Ton (Constant Speed)
750 Ton (VFD) 750 Ton (VFD) 750 Ton (VFD)
Chiller-1 Performance
*See Baseline Chiller Curves
*See Baseline Chiller Curves
*See Target Chiller Curves
*See Curve Fit to Measured Data
*See Curve Fit to Measured Data
Chiller-4 (Elec) Capacity
1000 Ton (Constant Speed)
1000 Ton (Constant Speed)
1000 Ton (VFD) 1000 Ton (VFD) 1000 Ton (VFD)
Chiller-4 Performance
*See Baseline Chiller Curves
*See Baseline Chiller Curves
*See Target Chiller Curves
*See Curve Fit to Measured Data
*See Curve Fit to Measured Data
Chiller-5 (Elec) Capacity
1000 Ton (Constant Speed)
1000 Ton (Constant Speed)
1000 Ton (VFD) 1000 Ton (VFD) 1000 Ton (VFD)
Chiller-5 Performance
*See Baseline Chiller Curves
*See Baseline Chiller Curves
*See Target Chiller Curves
*See Curve Fit to Measured Data
*See Curve Fit to Measured Data
Chiller-6 (Elec) Capacity
1000 Ton (Constant Speed)
1000 Ton (Constant Speed)
1000 Ton (VFD) 1000 Ton (VFD) 1000 Ton (VFD)
Chiller-6 Performance
*See Baseline Chiller Curves
*See Baseline Chiller Curves
*See Target Chiller Curves
*See Curve Fit to Measured Data
*See Curve Fit to Measured Data
*The chiller curves are presented in Appendix 2.
Figure 6.1: Chiller Retrofit ECM Model Inputs
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Section 6 - ECM 4: Chiller Plant Retrofit 21
6.2
6.2.1
Chiller performance improves when higher temperature CHW is produced. For example, a typical centrifugal chiller's efficiency can be improved 15 to 25% when producing CHW at 55°F versus 42°F. In addition, the use of medium temperature CHW is a common method of preventing uncontrolled dehumidification while conditioning the sensible loads, thus significantly improving the savings available from free cooling waterside economization.
Low CHW temperatures are required to meet the building load during hot summer days. Chiller performance improvisation, without compromising capacity requirements, can be improved by incorporating CHW supply-temperature reset controls. The BMS automatically resets the Chilled Water Supply Temperature (CHWST) setpoint in response to outside air temperature conditions. Internal operation of the chiller remains within the factory-supplied Chiller Plant Controls.
However, any increase in CHWST results in greater variability of the CHW pumping system’s energy consumption. This penalty can be minimized by tuning the system to maintain minimum design flow through the AHU coils.
6.2.2
The CHWST setpoint was manually maintained at a constant 44°F temperature during most of the chiller plant operating hours.
6.2.3
The performance contract requires Johnson Controls to install a functional CHWST reset control system capable of 42°F to 50°F reset based on two-way valve positions (Contract Target).
Johnson Controls determined based on the field conditions that outside air temperature reset will better suit ESB’s needs. Also, it was determined that the increased tenant cooling requirements cannot be met with a 50°F high limit. Therefore, Johnson Controls implemented 42°F to 48°F CHWST reset for 65°F to 55°F outside air temperature (PY Target, PY ECM Performance).
ESB operated CHWST reset ECM equipment in the manual mode at constant 42°F setpoint during 2014 summer to satisfy tenant CHWST requirements (Actual Operation).
Johnson Controls retested the ECM in December 2014 for auto mode operation and found it to be working correctly during the test period. ESB is planning on operating the ECM in auto mode during 2015 summer.
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Section 6 - ECM 4: Chiller Plant Retrofit 22
6.2.4
The implementation of CHWST reset control was verified by analyzing CHWST vs. time. The analyzed plots are presented in Appendix 3. The data for the analysis was retrieved from the Metasys trend repository and from FPI’s trend archive.
Results from the trending analysis were used to generate the following eQUEST Model inputs that determine the ECM savings.
6.3
6.3.1
During designed operating conditions, the Pre-Installation CHW loop was running at less than 10°F CHW delta-T conditions. This lower CHW delta-T decreases chiller efficiency and also increases CHW pump flow thereby its electric power consumption. A low delta-T also inhibits the ability of the chiller to operate at peak capacity. Hence, increasing the CHW loop delta-T to an optimal design setting was desired.
CHW loop delta-T was increased by:
Changing out the three-way valves for two-way valves in the Pre-Installation AHUs that were included in the project
Minimizing CHW flow rate using CHW pump VFD automation
Post-Installation CHW loop delta-T was targeted to operate close to 10°F at design conditions. This ECM improves energy savings by increasing chiller efficiency and also improves operational capability by increasing chiller capacity.
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Section 6 - ECM 4: Chiller Plant Retrofit 23
6.3.2
The following conditions were observed during the Pre-Installation building audit:
Low Zone CHW loop design condition delta-T: less than 7.8°F
Mid Zone CHW loop design condition delta-T: less than 6°F
High Zone CHW loop design condition delta-T: less than 6.9°F
6.3.3
In order to achieve the objective of this ECM, the performance contract required Johnson Controls to:
Replace the three-way valves with two-way valves in the Pre-Installation AHUs that were included in project and minimize CHW flow rate using CHW pump VFD automation (ECM Target).
The above scope was verified to be implemented by Johnson Controls (ECM Performance).
Most of the three way valves in ESB’s lobby are manually held open and the lobby is kept cool during summer. Several floors in the low zone are empty and the CHW pipes are flanged off (so no load). This contributes to the low delta-T in the low zone. Existence of 3‐way valves is not local to the lobby but to parts of the entire building. The replacement of those 3‐way valves is ESB's responsibility and ESB is currently working on issuing a PO for the replacements. Three way valves contribute to the low delta-T in the high zone and mid zone. Johnson Controls trended the loop delta-T under part-load conditions and the summary of the results are shown below (Actual Operation). The details of the analysis are shown in the Appendix 3.
Low Zone CHW loop part-load condition delta-T: 2°F to 8°F
Mid Zone CHW loop part-load condition delta-T: 3°F to 11°F
High Zone CHW loop part-load condition delta-T: 3°F to 9°F
6.3.4
The implementation of CHW loop delta-T was verified by checking the two-way valve implementation and the CHW VFD automation implementation. Actual building operation was verified by analyzing CHW loop delta-T vs. time. The analyzed plots are presented in this Report’s Appendix 3. The data for the analysis was retrieved from the Metasys trend repository and from FPI’s trend archive.
The following eQUEST Model inputs were used to determine the ECM savings:
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Section 6 - ECM 4: Chiller Plant Retrofit 24
Contract Baseline
PY Adjusted Baseline
PY Target PY ECM
Performance PY Actual Operation
Low Zone Loop Delta T
7.8°F (At Design Load)
7.8°F (At Design Load)
10°F (At Design Load)
10°F (At Design Load)
10°F (At Design Load)
Mid Zone Loop Delta T
<6°F (At Design Load)
<6°F (At Design Load)
10°F (At Design Load)
10°F (At Design Load)
10°F (At Design Load)
High Zone Loop Delta T
<6°F (At Design Load)
<6°F (At Design Load)
10°F (At Design Load)
10°F (At Design Load)
10°F (At Design Load)
Figure 6.3: CHW Loop Delta-T Enhancement ECM Model Inputs
6.4
6.4.1
This ECM automated the manually-controlled variable flow CHW system into an automatically controlled variable flow CHW system. The pump flow is automatically controlled to meet the CHW loop differential pressure setpoint. The installed system was tuned in the field to find the correct differential pressure setpoint enabling system to meet varying building load conditions.
Varying the speed of a motor to match the actual load improves control as well as reduces electrical motor power (kW), which may result in both comfort improvement and electrical energy savings.
Varying the speed of the motor is accomplished by varying voltage and frequency to the motor. The motor is connected to the CHW pump. As the system’s load changes, consequently so does the required motor driven output. A control program and the VFD will modulate the speed of the motor and match the output to the load. By reducing the speed of an electric motor, the energy required by the motor is reduced significantly. The actual power required is proportional to the cube of the speed. For example, if a motor’s speed is reduced to 80%, the motor’s energy consumption is decreased by approximately 50%. The theoretical energy savings through speed reduction is shown in the general relationship below:
(bhp2/bhp1)= (W2/W1)^3
where:
w2 = VFD controlled motor speed (varies)
w1 = motor/fan/pump existing speed (constant)
bhp2 = VFD controlled motor brake horsepower (varies)
bhp1 = Brake horsepower required before VFD is installed
The generic pump characteristic plot below illustrates that generic pump power consumption reduces with reduction in VFD speed. For example, reducing the VFD speed by 10% reduces pump energy usage by 27%.
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Section 6 - ECM 4: Chiller Plant Retrofit 25
Figure 6.4: Reduction in Generic Pump Power Consumption when Retrofitted with VFD
Two-way valves on the cooling coils ensure that CHW is supplied only when there is demand at the AHU. Hence, two-way valves create differential pressure variation in the CHW loop. The VFD speed is reduced when loop differential pressure decreases and the loop minimum flow can still be maintained.
In addition to the energy savings, this ECM increases equipment reliability and decreases operating cost by reducing the load on the bearings.
6.4.2
All CHW pumps were equipped with VFDs. But the drives were not set up to adjust speed automatically with varying building differential pressure. All VFDs were operating at constant full speed during most of the operating times.
6.4.3
The performance contract requires Johnson Controls to install a functional CHW pump VFD automation system capable of automatically varying VFD speed between 100% and 50% (min) to meet building differential pressure setpoint (ECM Target). The unit is fully installed for automatically varying VFD Speed between 100% and 33% (ECM Performance).
Trending analysis shows that, in 2014, the CHW pump VFDs were run in the manual mode at reduced speeds (Actual Operation). The verification indicates that:
Low Zone pumps were operating at an average speed of 59%.
Mid Zone pumps were operating at an average speed of 67%.
High Zone pumps were operating at an average speed of 67%.
CHW pumps in the automatic mode used to go offline in the event of a temporary control system outage. ESB could not risk temporary loss of CHW pumps due to stringent new tenant requirements. Therefore, ESB had to operate the CHW pumps in the manual mode. ESB installed a new UPS/RIB relay system in late 2014 summer that will prevent loss of CHW pumps in the event of a control system outage. This installation will help ESB operate the ECM in the automatic mode in 2015 summer.
Empire State Building Performance Year 4 M&V Report
Section 6 - ECM 4: Chiller Plant Retrofit 26
6.4.4
The implementation of CHW pump VFD automation was verified by checking the Metasys software. Actual building operation was verified by analyzing VFD speed vs. time. The analyzed plots are presented in Appendix 3. The data for the analysis was retrieved from the Metasys trend repository and from FPI’s trend archive.
Results from the trending analysis were used to generate the following eQUEST Model inputs that determine the ECM savings.
Contract Baseline PY Adjusted Baseline PY Target PY ECM Performance PY Actual Operation
Flow Ctrl/Min
VFD Manual (100% Speed All Times)
VFD Manual (100% Speed All Times)
VFD Auto (100% to 50% Min)
VFD Auto (100% to 33% Min)
VFD Manual (59% average)
Flow Ctrl/Min
VFD Manual (100% Speed All Times)
VFD Manual (100% Speed All Times)
VFD Auto (100% to 50% Min)
VFD Auto (100% to 33% Min)
VFD Manual (67% average)
Flow Ctrl/Min
VFD Manual (100% Speed All Times)
VFD Manual (100% Speed All Times)
VFD Auto (100% to 50% Min)
VFD Auto (100% to 33% Min)
VFD Manual (67% average)
Figure 6.5: CHW Pump VFD Automation ECM Model Inputs
6.5
6.5.1
Chiller performance increases significantly at lower CW temperatures. CW supply-temperature-reset strategy was implemented to provide low temperature CW, to the extent allowed by the chiller manufacturer. Cooling tower fan power increases to produce lower temperature CW, but chiller efficiency gains will typically dominate the economic considerations of this optimization strategy.
Most of the energy consumed by a chiller is used to move refrigerant vapor from the evaporator (low pressure) to the condenser (high pressure). As the pressure differential between the evaporator and condenser increases, the compressor must work harder to move the refrigerant. Lowering CW temperature decreases this pressure differential, so the compressor does less work. Electric chiller efficiency improves with decreased CW supply temperature.
Cooling tower controls are initially set to achieve 70°F tower water during design conditions. When ambient conditions are appropriate, the controls can be reset to produce water that is cooler than 70°F. The cooling tower water supply temperature was reset to achieve 5°F cooling tower approach above ambient wet-bulb temperature and it will generate significant energy savings without wasting cooling tower fan energy. The reset was programmed to be 60°F to 75°F, when outside air wet bulb temperature was between 55°F and 70°F.
Empire State Building Performance Year 4 M&V Report
Section 6 - ECM 4: Chiller Plant Retrofit 27
6.5.2
The cooling tower water supply temperature setpoint was manually maintained at a constant 70°F temperature during most of the operating times.
6.5.3
The performance contract requires Johnson Controls to install a functional CW reset control system that is capable of achieving 65°F to 70°F reset (Contract Target).
The CWST reset was programmed in the field as 60°F to 75°F reset (which is operator adjustable) to suit field conditions (PY Target and PY ECM Performance). The CWST reset logic was switched to auto mode for the first time on August 19, 2014. It was observed that CWST reset was responding to changes in OADPT and the towers were not capable of achieving 5°F approach. The programming was changed on August 25, 2014 so that CWST reset would respond to OAWBT and to a 7°F tower approach. This change has resulted in reduced tower fan operation. The base project incorporated an automatic 72°F CWST setpoint when the steam chillers are operated.
Trending analysis shows that the building operation personnel manually maintained CW supply temperature at 65°F most of the time in 2014 summer to satisfy tenant CW requirements (Actual Operation).
ESB will use the ECM in the automatic mode in 2015 summer.
6.5.4
The implementation of CW supply temperature reset controls was verified by analyzing Metasys programming. Actual building operation was verified by analyzing CW supply temperature vs. time trends. The analyzed plots are presented in Appendix 3. The data for the analysis was retrieved from the Metasys trend repository and from FPI’s trend archive.
Results from the trending analysis were used to generate the following eQUEST Model inputs that determine the ECM savings.
Contract Baseline
PY Adjusted Baseline
PY Target PY ECM Performance PY Actual Operation
Setpoint Control 70°F Fixed 70°F Fixed 60°F to 75°F Reset 60°F to 75°F Reset 65°F Fixed (Manual)
Figure 6.6: CW Supply Temperature Model Inputs
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Section 6 - ECM 4: Chiller Plant Retrofit 28
6.6
6.6.1
The cooling tower has ten cells, each of which is fitted with a separate cooling fan. Eight of the fans are single speed On/Off type. Two of the fans were fitted with manually controllable VFD.
This ECM automated the manually controlled cooling tower VFD system into an automatically controlled cooling tower VFD system. The fan speed is now automatically controlled to meet the Cooling Tower Water Leaving Temperature (CTWLT) setpoint. In addition, controls were installed to automatically stage the two fan VFDs.
Varying the speed of a motor to match the actual load improves control as well as reduces electrical motor power (kW) which typically results in both comfort improvement and electrical energy savings.
Varying the speed of the motor is accomplished by varying voltage and frequency to the fan motor. As a consequence of the system load changes, the required motor driven output is changed also. A control program and the VFD modulate the speed of the motor matching the output to the load. By reducing the speed of an electric motor, the energy required by the motor is reduced significantly. The actual power required is proportional to the cube of the speed. For example, if a motor’s speed is reduced to 80%, the motor’s energy consumption is decreased by approximately 50%. The theoretical energy savings through speed reduction is shown in the general relationship below:
(bhp2/bhp1)= (W2/W1)^3
where:
w2 = VFD controlled motor speed (varies)
w1 = motor/fan/pump existing speed (constant)
bhp2 = VFD controlled motor brake horsepower (varies)
bhp1 = Brake horsepower required before VFD is installed
The generic pump characteristic plot below illustrates that generic pump power consumption reduces with reduction in VFD speed. For example, reducing the VFD speed by 10% reduces pump energy usage by 27%.
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Section 6 - ECM 4: Chiller Plant Retrofit 29
Figure 6.7: Reduction in Generic Fan Power Consumption when Retrofitted with VFD
In addition to the energy savings, this ECM increases equipment reliability and decreases operating cost by reducing the load on the bearings.
6.6.2
The cooling tower has ten cells each of which is fitted with a separate cooling fan. Eight of the fans are single speed On/Off type. Two of the fans were fitted with manually controllable VFD.
6.6.3
The performance contract requires Johnson Controls to install an automatic cooling tower VFD system (ECM Target).
Johnson Controls verified that the manually-controlled cooling tower VFD system was converted into an automatically-controlled cooling tower VFD system. The fan speed is now automatically controlled to meet the CTWLT setpoint. In addition, controls were installed to automatically stage the two fan VFDs (ECM Performance).
2014 trending analysis shows that the ECM equipment was operated as designed (Actual Operation).
6.6.4
The implementation of cooling tower fan VFD automation was verified by analyzing VFD speed trends. The analyzed plots are presented in this Report’s Appendix. The data for the analysis was retrieved from the Metasys trend repository and from FPI’s trend archive.
Results from the trending analysis were used to generate the following eQUEST Model inputs that determine the ECM savings.
Contract Baseline
PY Adjusted Baseline
PY Target PY ECM
Performance PY Actual Operation
Tower Fan VFD One Speed
Fan One Speed
Fan VFD on
Towers 4 and 5 VFD on
Towers 4 and 5 VFD on
Towers 4 and 5
Figure 6.8: Cooling Tower Fan VFD Automation ECM Model Inputs
Empire State Building Performance Year 4 M&V Report
Section 6 - ECM 4: Chiller Plant Retrofit 30
6.7
6.7.1
This ECM automated the manually-controlled variable flow CW system into an automatically controlled variable flow CW system. The pump flow is automatically controlled to meet CW flow setpoint determined by the electric chiller loading conditions.
Varying the speed of a motor to match the actual load improves control as well as reduces electrical motor power (kW) which results in both comfort improvement and electrical energy savings.
Varying the speed of the motor is accomplished by varying voltage and frequency to the motor. The motor is connected to the CW pump. As the system load changes, consequently, so does the required motor driven output. A control program and the VFD will modulate the speed of the motor and match the output to the load. By reducing the speed of an electric motor, the energy required by the motor is reduced significantly. The actual power required is proportional to the cube of the speed. For example, if a motor’s speed is reduced to 80%, the motor’s energy consumption is decreased by approximately 50%. The theoretical energy savings through speed reduction is shown in the general relationship below:
(bhp2/bhp1)= (W2/W1)^3
where:
w2 = VFD controlled motor speed (varies)
w1 = motor/fan/pump existing speed (constant)
bhp2 = VFD controlled motor brake horsepower (varies)
bhp1 = Brake horsepower required before VFD is installed
The generic pump characteristic plot below illustrates that generic pump power consumption reduces with reduction in VFD speed. For example, reducing the VFD speed by 10% reduces pump energy usage by 27%.
Figure 6.9: Reduction in Generic Pump Power Consumption when Retrofitted with VFD
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Section 6 - ECM 4: Chiller Plant Retrofit 31
In addition to the energy savings, this ECM increases equipment reliability and decreases operating cost by reducing the load on the pump bearings.
6.7.2
All CW pumps were equipped with VFDs, but the drives were not configured to adjust speed automatically with varying chiller load. All VFDs were operating at constant full speed during most of the operating times.
6.7.3
The savings from this ECM were not guaranteed in the contract (ECM Target).
Johnson Controls installed a functional CW pump VFD automation system that is capable of automatically varying VFD speed to meet CW flow requirements set by the electric chiller load conditions. CW pump VFD automation cannot be used when the steam chillers are operational (ECM Performance).
Trending analysis shows that the CW pump VFDs were run in the manual mode in 2014 at an average speed of 80% (Actual Operation).
ESB is unable to use this ECM that reduces CW flow due to new tenant requirements that require high CW flow. ESB plans on doing a hydronic study in 2015 that will help them to operate this ECM in the automatic mode.
6.7.4
The implementation of CW pump VFD automation was verified by checking the Metasys software. Actual building operation was verified by analyzing VFD speed vs. time. The analyzed plots are presented in this Report’s Appendix. The data for the analysis was retrieved from the Metasys trend repository and from FPI’s trend archive.
Results from the trending analysis were used to generate the following eQUEST Model inputs that determine the ECM savings.
Contract Baseline
PY Adjusted Baseline
PY Target PY ECM
Performance PY Actual Operation
CW Pump Control
100% Fixed 100% Fixed 100% Fixed VFD Auto (100%
to 33% Min) 80% Manual
(Average)
Figure 6.10: CW Pump VFD Automation ECM Model Inputs
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Section 7 - ECM 5: Tenant Energy Management Portal 32
7.
The savings numbers associated with the TEM is shown below:
PY Target Performance savings was calculated to be $27,334 by using 3.02% annual escalation rate.
PY ECM Performance savings was calculated to be $0.
PY Actual Operation savings was calculated to be $0.
7.1
7.1.1
Johnson Controls set up an improvised energy dashboard for the customer. The dashboard was developed using Johnson Controls’ Gridlogix software and functions as a web-based tool that displays a number of energy use variables.
Johnson Controls provides a connection to the building controls system with automatic data transfers of electric submeter data. The dashboard shows energy use compared to relevant variables. It also provides information for each floor of the building and is password protected. A series of alarms is triggered if energy use exceeds expected ranges on any tenant floor. The tenant is able to view current energy consumption in kilowatts along with associated metrics (kW/sq. ft., kW, kWh etc.) and compare it to historical consumption. The tenant can also view their comparative consumption relative to other tenants who are under the same ownership structure.
A web-based portal displaying tenant-specific electric utility consumption is metered building-wide using a Satec BFM136 utility grade smart-meter network, endorsing energy-efficient practices within the tenant space.
The EnNET®/AEM platform provides 15 minute meter data and creates a normalized data base that can be used to support Time Series profiling, reporting to ISO and future integration with property management software for creating invoices based on current meter read should a tenant terminate a lease.
7.1.2
Johnson Controls’ Gridlogix software verified the connectivity to each meter. Gridlogix was not responsible for the physical connection (wired or wireless) to the existing main/sub meters or a third party device required to collect the 15 minute pulse data. The data was, however, in a protocol format that Johnson Controls supports; protocols such as Modbus, BACnet®, Simple Network Management Protocol. The data protocol used was BACnet, which fully supported auto discovery. Gridlogix commissioned and verified the EnNET software connection and read the meter data properly. The Gridlogix software established the rules base and monitored notifications for successfully creating, archiving and ensuring quality of service. Gridlogix, too, commissioned the AEM application and built the web pages to properly display metering data,
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Section 7 - ECM 5: Tenant Energy Management Portal 33
time series analysis, real-time metering information and created notifications based on usage parameters.
7.1.3
The deployment of TEM was completed in Year 2011. Due to increasing installation of submeters and requests to contemporize existing TEM, Johnson Controls proceeded with the development of enhanced TEM. During third quarter of Year 2012, a new dashboard, TEM2, went into production to meet and exceed the growing platform at the site. TEM2 platform includes customer facing interactive applications such as:
A green kiosk displaying ‘how to save energy’ tips
Building/industry tweets
Sustainability trending
Information on various retrofits performed at site
Tenant-specific dashboard to display various matrices
Reporting module – tenant and administration based
Energy analyzer with ability to view sub-metering at a granular level
The new platform was launch in first quarter of 2013. The platform includes two front end interfaces, namely, tenant portal and admin portal. The tenant portal allows tenants to view metered data based on each floor they occupy along with ability to dissect data to display various loads within each leased floors. This includes, floor by floor analysis for multi-floor tenants, and for large tenants, ability to view plug, HVAC and lighting loads along with a cost widget section which enables tenants to review estimated energy costs and savings based on their actual energy rates. The admin portal allows ESB to view metered data by building, floor, or by suite. It allows ESB to monitor efficient tenants and place best practices and incentives to other tenants.
ESB and Johnson Controls agreed to not claim TEM savings in 2014 because of Tenant submeter inaccuracy issues.
7.1.4
The contract methodology calls for observing tenant behavior improvement by measuring space temperature variations to setpoint. Johnson Controls finds that this methodology is not practically possible. Given the magnitude of this ECM savings relative to the entire project savings and the practical complexity in measurement, Johnson Controls requests the customer that this ECM savings be made non-measured.
Empire State Building Performance Year 4 M&V Report
Section 8 - ECM 6: Low Zone and Mid Zone PFHX 34
8.
The savings numbers associated with the PFHX is shown below:
PY Target Performance savings was calculated to be $202,899 by using 2014 field measurements.
PY ECM Performance savings was calculated to be $202,899 by using 2014 field measurements.
PY Actual Operation savings was calculated to be $202,899 by using 2014 field measurements.
8.1
8.1.1
ESB’s CHW requirement during winter/shoulder months has increased in the past few years due to change in tenant occupancy patterns. Chiller plant efficiency is low when the plant is operated under low part-load winter/shoulder conditions. PFHXs can provide free cooling by using the cold cooling tower water to chill the CHW and keep the mechanical chillers off. Energy is saved by avoiding chiller plant operation during low load.
8.1.2
Electric chillers were primarily used to produce chilled water during winter/shoulder months.
8.1.3
A 500 ton PFHX was installed in the low zone and a 1000 ton PFHX was installed in the mid zone. Cold tower water is redirected through the cold side of the two PFHXs when the OAWBT is less than 43°F. CHW is cooled by redirecting it through the hot side of the PFHXs.
8.1.4
The PFHXs are guaranteed to achieve 2.6°F approach temperature (including the measurement tolerance of 0.6°F) when operating under design conditions shown in Figure 8.1. The approach temperatures and PFHX cooling loads were measured in the field (see Appendix 4). It can be observed that the PFHXs did not operate near design load conditions, but the approach temperature was within the 2.6°F limit during most conditions.
PFHX Capacity
(Tons) Design Cold Side
Flow (gpm) Design Hot Side
Flow (gpm)
Low Zone PFHX 500 1,200 1,200
Mid Zone PFHX 1,000 2,400 2,400
Figure 8.1: PFHX design operating condition
The process of incorporating a PFHX model into the ESB eQUEST Model is very complex. Therefore, the savings are directly derived by measuring the PFHX cooling load and calculating the corresponding electric chiller avoided cost. The field data for the first three months in the PY is missing and it is replaced with a degree day based average cooling load calculated from PFHX field data collected during rest of the PY months.
Empire State Building Performance Year 4 M&V Report
Appendix 35
Appendix List
Appendix 1: BMS Retrofit Data Analysis
Appendix 2: Chiller Retrofit Data Analysis
Appendix 3: Chiller Plant Retrofit Data Analysis
Appendix 4: PFHX Data Analysis
Appendix 5: ESB eQUEST Model Input Table
Appendix 6: Baseline Adjustments
Appendix 7: Utility Analysis
Empire State Building Performance Year 4 M&V Report
Appendix 1: BMS Retrofit Data Analysis 36
Appendix 1: BMS Retrofit Data Analysis
Damper Retrofit and DCV
The goal of the ECM was to reduce the building’s overall outside air intake by retrofitting the non-Alerton AHU with DCV and modulating dampers. Minimum outside air ventilation is possible when CO2-based DCV is combined with the ability to open dampers just enough to satisfy the ventilation demand. This cannot be achieved with the old two-position dampers, but can be achieved with CO2 based DCV controls and modulating dampers.
Demand-controlled ventilation is used to modulate outside air ventilation based on real time occupancy. DCV reduces over-ventilation that may result when existing AHUs are set to provide ventilation for a maximum assumed occupancy.
Also, the dampers modulate based on outside air temperature for temperature/economizer control.
Johnson Controls retrofitted non-Alerton AHUs with CO2 sensor on the return air duct. DCV was programmed for outside air activation at 800 ppm ‘return air CO2’ threshold. Also, Johnson Controls retrofitted non-Alerton AHU units by replacing their two-position pneumatic damper system with new dampers (if broken), new actuators and DDC controls. The new damper system has the capability to modulate anywhere between 0% to 100% open/close position.
Outside air dampers are in their minimum position when the CO2 level is below the 800 ppm threshold and the temperature control is not calling for dampers to open further. Outside air dampers modulate linearly between their minimum (10%) position and full open (100%) position when the CO2 level is between 800ppm and 1000 ppm, and/or when the temperature control is calling for dampers to open further. The analyzed data trends (shown in this section) indicated that outside damper position increased when the CO2 ppm in the return air increased above the threshold level of 800ppm. The data trends demonstrate that the DCV system was installed and is operational.
Figures A-1.1 through Figures A-1.4 shows the behavior of dampers relative to return air CO2 levels for a few sample AHUs.
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Appendix 1: BMS Retrofit Data Analysis 37
Figure A-1.1: AHU 27-3 Mixed Damper Position vs Return Air CO2 Level
Figure A-1.2: AHU 68-2 Mixed Damper Position vs Return Air CO2 Level
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Appendix 1: BMS Retrofit Data Analysis 38
Figure A-1.3: AHU 51-4 Mixed Damper Position vs Return Air CO2 Level
Figure A-1.4: AHU 68-3 Mixed Damper Position vs Return Air CO2 Level
Empire State Building Performance Year 4 M&V Report
Appendix 1: BMS Retrofit Data Analysis 39
Fan Scheduling
The building utilizes fans to provide AHU supply air, exhaust toilet space air and to exhaust building space air. Prior to the performance contract, the fans did not have the DDC controls to automatically schedule On/Off. Johnson Controls installed DDC controls on the AHU’s to automatically schedule On/Off.
As part of the BMS retrofit, all non-Alerton AHU supply fans were connected to BMS and the scheduling feature was enabled.
Mid Zone/High Zone AHU Supply Fan Scheduling
Supply fan run status data was taken from the Metasys data server and the trend data for sample units are shown in Figures A-1.6 through A-1.14. Figure A-1.5 shows the average fan operating hours.
AHU Name Average
Operating Hours
AHU 26-2 13.0
AHU 30-5 13.9
AHU 40-1 14.0
AHU 42-2 13.8
AHU 48-4 13.9
AHU 51-3 14.0
AHU 51-4 13.9
AHU 68-3 13.6
AHU 76-1 14.0
Average 13.8
Figure A-1.5: Average Daily Operating Hours for AHU Fans
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Appendix 1: BMS Retrofit Data Analysis 40
Figure A-1.6: AHU 26-2 Daily Operation Hours
Figure A-1.7: AHU 30-5 Daily Operation Hours
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Appendix 1: BMS Retrofit Data Analysis 41
Figure A-1.8: AHU 40-1 Daily Operation Hours
Figure A-1.9: AHU 42-2 Daily Operation Hours
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Appendix 1: BMS Retrofit Data Analysis 42
Figure A-1.10: AHU 48-4 Daily Operation Hours
Figure A-1.11: AHU 51-3 Daily Operation Hours
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Appendix 1: BMS Retrofit Data Analysis 43
Figure A-1.12: AHU 51-4 Daily Operation Hours
Figure A-1.13: AHU 68-3 Daily Operation Hours
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Appendix 1: BMS Retrofit Data Analysis 44
Figure A-1.14: AHU 76-1 Daily Operation Hours
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Appendix 2: Chiller Retrofit Data Analysis 45
Appendix 2: Chiller Retrofit Data Analysis
Chiller Curve Fit Modeling Methodology
Trended chiller data was used to create custom chiller performance curves in eQUEST for best fit of the data. The data that was used to calculate chiller performance includes:
Chiller input kW
CHWST
CHWRT (used for comparison and troubleshooting)
CHW flow rate
Condenser Water Leaving Temperature (CWLT) (used for comparison and troubleshooting)
Condenser Water Entering Temperature (CWET)
From the trended data, several output values were calculated, including
Chiller load (tons)
Adjusted chiller capacity, to account for CHWST and CWET impacts (this was calculated using the default eQUEST capacity adjustment curve, which is typical for most centrifugal chillers.)
% Full-load, using calculated adjusted capacity and calculated load
Chiller Efficiency (kW/ton)
To compare the DOE2 default curves to the actual trended chiller data, the chiller kW was calculated for the given trend conditions for all of the data points, which was then compared to the trended chiller kW by calculating the Mean Bias Error (MBE), and the Root Mean Square Error (RMSE). For the entire data set, an overall MBE and Coefficient of variation (Cv) for the RMSE was then calculated.
MBE =𝑘𝑊𝑚𝑒𝑎𝑠𝑢𝑟𝑒𝑑−𝑘𝑊𝑐𝑎𝑙𝑐𝑢𝑙𝑎𝑡𝑒𝑑
𝑘𝑊𝑚𝑒𝑎𝑠𝑢𝑟𝑒𝑑 𝐶𝑉(𝑅𝑀𝑆𝐸) =
√∑ (𝑘𝑊𝑚𝑒𝑎𝑠𝑢𝑟𝑒𝑑−𝑘𝑊𝑐𝑎𝑙𝑐𝑢𝑙𝑎𝑡𝑒𝑑)2𝑛
1𝑛
𝑘𝑊̅̅ ̅̅ ̅𝑚𝑒𝑎𝑠𝑢𝑟𝑒𝑑
The best fit was determined by applying the solver function in Microsoft Excel® to minimize the Coefficient of Variation for the data set, while using constraints to maintain the specified full-load ARI condition efficiency. For many of the chillers, limited data was available for standard ARI rating conditions (ARI rating conditions are 100% load at 85°F entering CWET and 44°F leaving CHWST). These ARI data points are values at which the eQUEST performance curves are normalized. For the chillers with no trended points at ARI conditions, engineering judgment was used to determine an acceptable ARI rating for the chiller. This involved finding the full-load points available, and adjusting the measured performance at that point to account for the variance in conditions from ARI rating conditions (e.g. a chiller operating at full-load with 75°F CWET has a lower kW/ton than the same chiller operating at 85°F CWET).
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Appendix 2: Chiller Retrofit Data Analysis 46
After finding a best-fit for the data by solving for the curves to minimize the coefficient of variation, these custom curves were used to calculate the ECM performance of the chillers. Target and ECM performance fit information for each chiller is shown on the following pages.
Figure A-2.1 compares the Baseline, contract target and 2014 ECM chiller performance numbers.
Baseline Target ECM Performance
Low Zone
Chiller-1
Rated Efficiency at ARI conditions (kW/ton)
0.74 0.80 0.65
IPLV - Integrated Part-load Value (kW/ton)
0.65 0.47 0.53
Curves Default DOE2 Centrifugal Curves
Default DOE2 Variable Speed Drive (VSD) Centrifugal Curves
Custom best-fit to trended data
Source Contract Contract Trended data
Mid Zone Chiller-4
Rated Efficiency at ARI conditions (kW/ton)
0.73 0.71 0.62
IPLV - Integrated Part-load Value (kW/ton)
0.64 0.42 0.52
Curves Default DOE2 Centrifugal Curves
Default DOE2 VSD Centrifugal Curves
Custom best-fit to trended data
Source Contract Contract Trended data
Mid Zone Chiller-5
Rated Efficiency at ARI conditions (kW/ton)
0.73 0.71 0.58
IPLV - Integrated Part-load Value (kW/ton)
0.64 0.42 0.47
Curves Default DOE2 Centrifugal Curves
Default DOE2 VSD Centrifugal Curves
Custom best-fit to trended data
Source Contract Contract Trended data
High Zone
Chiller-6
Rated Efficiency at ARI conditions (kW/ton)
0.85 0.82 0.62
IPLV - Integrated Part-load Value (kW/ton)
0.75 0.48 0.49
Curves Default DOE2 Centrifugal Curves
Default DOE2 VSD Centrifugal Curves
Custom best-fit to trended data
Source Contract Contract Trended data
Figure A-2.1: ESB Chiller Performance Summary
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Appendix 2: Chiller Retrofit Data Analysis 47
Low Zone Chiller-1 Performance Curves
Figure A-2.2: CH-1 Baseline, Target, and ECM Performance (Curve Fit) Curves at
42°F CHWST and 80°F CWET.
Figure A-2.3: CH-1 Baseline, Target, and ECM Performance (Curve Fit) Curves at
42°F CHWST and 75°F CWET
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Appendix 2: Chiller Retrofit Data Analysis 48
Figure A-2.4: CH-1 Baseline, Target, and ECM Performance (Curve Fit) Curves at
42°F CHWST and 65°F CWET
Figure A-2.5 shows the Cv and MBE associated with the Chiller-1 curve fit. The low MBE and reasonable Cv reflects a good curve fit.
CWET MBE Cv(RMSE)
60.00 -0.1% 42.4%
65.00 1.5% 19.3%
70.00 1.8% 13.5%
75.00 0.6% 13.1%
80.00 -3.4% 11.3%
85.00 6.2% 6.2%
Overall 0.1% 16.0%
Figure A-2.5: MBE and Cv Associated with Chiller-1 Curve Fit
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Appendix 2: Chiller Retrofit Data Analysis 49
Mid Zone Chiller-4 Performance Curves
Figure A-2.6: CH-4 Baseline, Target, and ECM Performance (Curve Fit) Curves at
42°F CHWST and 80°F CWET
Figure A-2.7: CH-4 Baseline, Target, and ECM Performance (Curve Fit) Curves at
42°F CHWST and 75°F CWET
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Appendix 2: Chiller Retrofit Data Analysis 50
Figure A-2.8: CH-4 Baseline, Target, and ECM Performance (Curve Fit) Curves at
42°F CHWST and 65°F CWET
Figure A-2.9 shows the Cv and MBE associated with the Chiller-4 curve fit. The low MBE and reasonable Cv reflects a good curve fit.
CWET MBE Cv(RMSE)
60.00 -34.4% 44.6%
65.00 -11.3% 14.0%
70.00 -6.9% 7.4%
75.00 -3.4% 17.4%
80.00 7.2% 21.3%
85.00 32.3% 32.3%
Overall 0.1% 22.4%
Figure A-2.9: MBE and Cv Associated with Chiller-4 Curve Fit
Empire State Building Performance Year 4 M&V Report
Appendix 2: Chiller Retrofit Data Analysis 51
Mid Zone Chiller-5 Performance Curves
Figure A-2.10: CH-5 Baseline, Target, and ECM Performance (Curve Fit) Curves at
42°F CHWST and 80°F CWET
Figure A-2.11: CH-5 Baseline, Target, and ECM Performance (Curve Fit) Curves at
42°F CHWST and 75°F CWET
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Appendix 2: Chiller Retrofit Data Analysis 52
Figure A-2.12: CH-5 Baseline, Target, and ECM Performance (Curve Fit) Curves at
42°F CHWST and 65°F CWET
Figure A-2.13 shows the Cv and MBE associated with the Chiller-5 curve fit. The low MBE and reasonable Cv reflects a good curve fit.
CWET MBE Cv(RMSE)
60.00 -1.5% 40.2%
65.00 7.8% 12.7%
70.00 -0.9% 15.6%
75.00 0.5% 9.2%
80.00 -3.3% 8.0%
85.00 5.4% 5.4%
Overall 0.1% 13.0%
Figure A-2.13: MBE and Cv Associated with Chiller-5 Curve Fit
Empire State Building Performance Year 4 M&V Report
Appendix 2: Chiller Retrofit Data Analysis 53
High Zone Chiller-6 Performance Curves
Figure A-2.14: CH-6 Baseline, Target, and ECM Performance (Curve Fit) Curves at
42°F CHWST and 80°F CWET
Figure A-2.15: CH-6 Baseline, Target, and ECM Performance (Curve Fit) Curves at
42°F CHWST and 75°F CWET
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Appendix 2: Chiller Retrofit Data Analysis 54
Figure A-2.16: CH-6 Baseline, Target, and ECM Performance (Curve Fit) Curves at
42°F CHWST and 65°F CWET
Figure A-2.17 shows the Cv and MBE associated with the Chiller-6 curve fit. The low MBE and reasonable Cv reflects a good curve fit.
CWET MBE Cv(RMSE)
60.00 4.7% 10.0%
65.00 -1.2% 10.2%
70.00 0.4% 8.2%
75.00 1.5% 6.8%
80.00 -1.4% 6.3%
85.00 -14.2% 14.9%
Overall -0.1% 8.1%
Figure A-2.17: MBE and Cv Associated with Chiller-6 Curve Fit
Empire State Building Performance Year 4 M&V Report
Appendix 3: Chiller Plant Retrofit Data Analysis 55
Appendix 3: Chiller Plant Retrofit Data Analysis
CHWST Reset
Figures A-3.1 through Figure A-3.4 shows the CHWST, CHWST setpoint and outside air temperature trends. The analysis uses 8 a.m. to 5 p.m. weekday trend data. It can be observed that the CHWST setpoint does not change with outside air temperature during summer and this indicates manual operation of the CHWST reset ECM.
Figure A-3.1: Low Zone Chiller 1 CHW Supply Temperature and CHW Supply Temperature
Setpoint, Outside Air Temperature versus Time
Figure A-3.2: Mid Zone Chiller 4 CHW Supply Temperature and CHW Supply Temperature
Setpoint, Outside Air Temperature versus Time
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Appendix 3: Chiller Plant Retrofit Data Analysis 56
Figure A-3.3: Mid Zone Chiller 5 CHW Supply Temperature and CHW Supply Temperature
Setpoint, Outside Air Temperature versus Time
Figure A-3.4: High Zone Chiller 6 CHW Supply Temperature and CHW Supply Temperature
Setpoint, Outside Air Temperature versus Time
Empire State Building Performance Year 4 M&V Report
Appendix 3: Chiller Plant Retrofit Data Analysis 57
CHW Loop Delta-T Enhancement
Figure A-3.5 showcases the frequency of low delta-T (°F) plant operation. The analysis uses 8 a.m. to 5 p.m. summer weekday trend data. It was observed that the low zone delta-T (°F) was operating mostly between 2°F to 8°F, the mid zone delta-T (°F) was operating between 3°F to 11°F and the high zone delta-T (°F) was operating between 3°F to 9°F. Zone delta-Ts (°F) are not fully operating as optimally desired. The root cause was found to be the existence of a number of three-way valves in the system, and the fact that the electric chillers are run at low load conditions. Also, the bypass valve opens during low load conditions and therefore, the delta-T (°F) across the chiller suffers. The bypass valve operation is unavoidable but the three-way valve situation can be improved in future projects. ESB is currently working on designing a project to replace the three-way valves with two-way valves.
Figure A-3.5: CHW Delta-T Histogram
Empire State Building Performance Year 4 M&V Report
Appendix 3: Chiller Plant Retrofit Data Analysis 58
CHW Pump VFD Automation
CHW pump VFDs were operated in the manual mode and Figure A-3.6 shows that the VFD speeds associated with the manual operation (50% to 82%).
Figure A-3.6: CHW Pump Speed Histogram
Empire State Building Performance Year 4 M&V Report
Appendix 3: Chiller Plant Retrofit Data Analysis 59
CW Supply Temperature Reset
CWST reset logic was switched to auto mode for the first time on August 19, 2014. It was observed upon data analysis that the CWST reset was incorrectly responding to changes in OADPT and the 5°F approach was not enough for the cooling towers. The programming was changed on August 25, 2014 so that CWST reset responds to OAWBT with a 7°F tower approach. The CWST reset logic is operating correctly now and it can be observed in Figure A-3.7 that the CWST meets the setpoint. Note that CWST and CTWLT shown in the Figure are the same parameters.
Figure A-3.7: Outside Air Temperature Wet Bulb, CW Temperature and
CW Temperature Setpoint vs Time
Empire State Building Performance Year 4 M&V Report
Appendix 3: Chiller Plant Retrofit Data Analysis 60
Cooling Tower Fan VFD Automation
The cooling tower has ten cells, each of which is fitted with a separate cooling fan. Eight of the fans are single speed On/Off type. Two of the fans were fitted with manually controllable VFD.
This ECM automated the manually-controlled cooling tower VFD system into an automatically controlled cooling tower VFD system. The fan speed is now automatically controlled to meet the CTWLT setpoint. Additionally, controls were installed to automatically stage the two fan VFDs.
The fan speed is automatically controlled to meet the CTWLT setpoint. Cooling Tower fan VFDs are operated in the automatic mode and Figure A-3.8 shows the VFD speed modulation.
Figure A-3.8: Cooling Tower Fan VFD Histogram
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Appendix 3: Chiller Plant Retrofit Data Analysis 61
CW Pump VFD Automation
CW pump VFDs were operated in the manual mode and Figure A-3.9 shows that the VFD speeds associated with the manual operation (40% to 100%).
Figure A-3.9: Cooling Water Pump VFD Histogram
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Appendix 4: PFHX Data Analysis 62
Appendix 4: PFHX Data Analysis
The low zone and mid zone PFHXs are guaranteed to achieve 2.6°F approach temperature (including the measurement tolerance of 0.6°F) when operating under design conditions shown in Figure 8.1. The approach temperatures and PFHX cooling loads were measured in the field are shown in Figure A-4.2 and FigureA-4.3. It can be observed that the PFHXs did not operate near design load conditions, but the approach temperature was within the 2.6°F limit during most conditions.
PFHX Capacity (Tons)
Design Cold Side Flow (gpm)
Design Hot Side Flow (gpm)
Low Zone PFHX 500 1,200 1,200
Mid Zone PFHX 1,000 2,400 2,400
Figure A-4.1: PFHX Design Operating Condition
Figure A-4.2: Low Zone Cooling Load vs Approach Temperature
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Appendix 4: PFHX Data Analysis 63
Figure A-4.3: Mid Zone Cooling Load vs Approach Temperature
The process of incorporating a PFHX model into the ESB eQUEST Model is very complex. Therefore the savings are directly derived by measuring the PFHX cooling load and calculating the corresponding electric chiller avoided cost. The cumulative PFHX cooling load recorded in the field is shown in Figure A-4.4 and FigureA-4.5.
Note: The field data for the first three months in the PY is missing and it is replaced with a degree day based average cooling load calculated from PFHX field data collected during rest of the PY months.
Figure A-4.4: Low Zone Cumulative Cooling Load
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Appendix 4: PFHX Data Analysis 64
Figure A-4.5: Mid Zone Cumulative Cooling Load
Empire State Building Performance Year 4 M&V Report
Appendix 5: ESB eQUEST Model Inputs and Outputs 65
Appendix 5: ESB eQUEST Model Inputs
Empire State Building Performance Year 4 M&V Report
Appendix 5: ESB eQUEST Model Inputs and Outputs 66
Contract Baseline Contract Target PY Adjusted
BaselinePY Target
PY ECM
Performance
PY Actual
OperationPY Actual Utility
% 10% 10%11% - per CHW
Zone
11% - per CHW
Zone
11% - per CHW
Zone
11% - per CHW
Zone
11% - per CHW
Zone
HVAC Setbacks No No Yes Yes Yes Yes Yes
Weather Location, Year NY, 2007 NY, 2007 NY, 2014 NY, 2014 NY, 2014 NY, 2014 NY, 2014
Electric Utility Rate Year 2007 2007 PY Contract Rate PY Contract Rate PY Contract Rate PY Contract Rate 2014
Steam Utility Rate Year 2007 2007 PY Contract Rate PY Contract Rate PY Contract Rate PY Contract Rate 2014
Number of Radiator Insulations Installed 0 6400 0 6400 6400 6400 6400
Radiative Wall U Value 0.209 0.122 0.209 0.122 0.102 0.102 0.102
North (U-value/SHGC) 0.48 / 0.645 0.365 / 0.448 0.58 / 0.645 0.365 / 0.448 0.274 / 0.395 0.274 / 0.395 0.274 / 0.395
East (U-value/SHGC) 0.48 / 0.645 0.384 / 0.325 0.58 / 0.645 0.384 / 0.325 0.320 / 0.27 0.320 / 0.27 0.320 / 0.27
South (U-value/SHGC) 0.48 / 0.645 0.384 / 0.325 0.58 / 0.645 0.384 / 0.325 0.337 / 0.27 0.337 / 0.27 0.337 / 0.27
West (U-value/SHGC) 0.48 / 0.645 0.384 / 0.325 0.58 / 0.645 0.384 / 0.325 0.324 / 0.27 0.324 / 0.27 0.324 / 0.27
Window Infiltration Multiplier 4 2 4 2 2 2 2
Low Loop
Chiller #1 (Elec) Capacity 750 750 VFD 750 750 VFD 750 VFD 750 VFD 750 VFD
kW/ton
See Baseline
Chiller Curves
(Contract)
See Target Chiller
Curves (Appendix
2)
See Baseline
Chiller Curves
(Contract)
See Target Chiller
Curves (Appendix
2)
See Target Chiller
Curves (Appendix
2)
See Target Chiller
Curves (Appendix
2)
See Target Chiller
Curves (Appendix
2)
Chiller #2 (STM) Capacity 1000 1000 1000 1000 1000 1000 1000
Overall COP 1.01 1.01
hp/ton 0.709 0.709
lbm/tonhr 13.9 13.9
Chiller StagingBaseload Electric
Chiller
Baseload Electric
Chiller
Electric Chiller
Only
Electric Chiller
Only
Electric Chiller
Only
Electric Chiller
Only
Electric Chiller
Only
CHW Pumping
Flow Ctrl /Min
VFD Manual
(100% Speed All
Times)
VFD Auto (100%
to 50% Min)
VFD Manual
(100% Speed All
Times)
VFD Auto (100%
to 50% Min)
VFD Auto (100%
to 50% Min)VFD Manual (59%) VFD Manual (59%)
Valve-Type 3-way 2-way 3-way 2-way 2-way 2-way 2-way
Pump Power (kW) 161 161 161 161 161 161 161
Total Pump Head (Feet) 258 258 258 258 258 258 258
Flow (gpm) 2310 /2 2310 /2 2310 /2 2310 /2 2310 /2 2310 /2 2310 /2
CHWST 44°F (Fixed)
42°F to 50°F
based on valve
position
44°F (Fixed)42°F @ 65°F OAT,
50°F @ 55°F OAT
42°F @ 65°F OAT,
50°F @ 55°F OAT42°F (Fixed) 42°F (Fixed)
Loop Delta T7.8°F (At Design
Load)
10°F (At Design
Load)
7.8°F (At Design
Load)
10°F (At Design
Load)
10°F (At Design
Load)
10°F (At Design
Load)
10°F (At Design
Load)
Windows
Vacancy
Utility Data
Radiator Insulation
Chiller Plant - Low
Loop
York Chiller
Curves
York Chiller
Curves
York Chiller
Curves
York Chiller
Curves
York Chiller
Curves
Empire State Building Performance Year 4 M&V Report
Appendix 5: ESB eQUEST Model Inputs and Outputs 67
Contract Baseline Contract Target PY Adjusted
BaselinePY Target
PY ECM
Performance
PY Actual
OperationPY Actual Utility
Mid Loop
Chiller #3 (Stm) Capacity 2000 2000 2000 2000 2000 2000 2000
Overall COP 1.09 1.09York Chiller
Curves
hp/ton 0.665 0.665 0
lbm/tonhr 13.8 13.8 0
Chiller #4 (Elec) Capacity 1000 1000 VFD 1000 1000 VFD 1000 VFD 1000 VFD 1000 VFD
Chiller Curves
See Baseline
Chiller Curves
(Contract)
See Target Chiller
Curves (Appendix
2)
See Baseline
Chiller Curves
(Contract)
See Target Chiller
Curves (Appendix
2)
See Target Chiller
Curves (Appendix
2)
See Target Chiller
Curves (Appendix
2)
See Target Chiller
Curves (Appendix
2)
Chiller #5 (Elec) Capacity 1000 1000 VFD 1000 1000 VFD 1000 VFD 1000 VFD 1000 VFD
Chiller Curves
See Baseline
Chiller Curves
(Contract)
See Target Chiller
Curves (Appendix
2)
See Baseline
Chiller Curves
(Contract)
See Target Chiller
Curves (Appendix
2)
See Target Chiller
Curves (Appendix
2)
See Target Chiller
Curves (Appendix
2)
See Target Chiller
Curves (Appendix
2)
Chiller StagingBaseload Electric
Chillers
Baseload Electric
Chillers
Electric Chiller
Only
Electric Chiller
Only
Electric Chiller
Only
Electric Chiller
Only
Electric Chiller
Only
CHW Pumping
Flow Ctrl /Min
VFD Manual
(100% Speed All
Times)
VFD Auto (100%
to 50% Min)
VFD Manual
(100% Speed All
Times)
VFD Auto (100%
to 50% Min)
VFD Auto (100%
to 33% Min)VFD Manual (67%) VFD Manual (67%)
Valve-Type 3-way 2-way 3-way 2-way 2-way 2-way 2-way
CHWST 44°F (Fixed)
42°F to 50°F
based on valve
position
44°F (Fixed)42°F @ 65°F OAT,
50°F @ 55°F OAT
42°F @ 65°F OAT,
50°F @ 55°F OAT44°F (Fixed) 44°F (Fixed)
Loop Delta T<6°F (At Design
Load)
10°F (At Design
Load)
<6°F (At Design
Load)
10°F (At Design
Load)
10°F (At Design
Load)
10°F (At Design
Load)
10°F (At Design
Load)
Chiller Plant - Mid
Loop
York Chiller
Curves
York Chiller
Curves
York Chiller
Curves
York Chiller
Curves
Empire State Building Performance Year 4 M&V Report
Appendix 5: ESB eQUEST Model Inputs and Outputs 68
Figure A-5.1: 2014 eQUEST Model Inputs Table
Contract Baseline Contract Target PY Adjusted
BaselinePY Target
PY ECM
Performance
PY Actual
OperationPY Actual Utility
High Loop 0 0
Chiller #6 (Elec) Capacity 1000 1000 VFD 1000 1000 VFD 1000 VFD 1000 VFD 1000 VFD
Chiller Curves
See Baseline
Chiller Curves
(Contract)
See Custom
Curves
(Appendix 2)
See Baseline
Chiller Curves
(Contract)
See Custom
Curves
(Appendix 2)
See Custom
Curves
(Appendix 2)
See Custom
Curves (Appendix
2)
See Custom
Curves (Appendix
2)
Chiller #7 (Stm) Capacity 1294 1294 1294 1294 1294 1294 1294
Overall COP 1.03 1.03
hp/ton 0.724 0.724
lbm/tonhr 13.4 13.4
Chiller StagingBaseload Electric
Chillers
Baseload Electric
Chillers
Electric Chillers
Only
Electric Chillers
Only
Electric Chillers
Only
Electric Chillers
Only
Electric Chillers
Only
0
CHW Pumping
VFD Manual
(100% Speed All
Times)
VFD Auto (100%
to 50% Min)
VFD Manual
(100% Speed All
Times)
VFD Auto (100%
to 50% Min)
VFD Auto (100%
to 33% Min)VFD Manual (67%) VFD Manual (67%)
Valve-Type 3-way 2-way 3-way 2-way 2-way 2-way 2-way
CHWST 44°F (Fixed)
42°F to 50°F
based on valve
position
44°F (Fixed)42°F @ 65°F OAT,
50°F @ 55°F OAT
42°F @ 65°F OAT,
50°F @ 55°F OAT42°F (Fixed) 42°F (Fixed)
Loop Delta T6.9°F (At Design
Load)
10°F (At Design
Load)
6.9°F (At Design
Load)
10°F (At Design
Load)
10°F (At Design
Load)
10°F (At Design
Load)
10°F (At Design
Load)
Number of Cells 10 10 10 10 10 10 10
Setpoint Control 70°F FixedWet Bulb Reset
(65°F Min)70°F Fixed Wet Bulb Reset (60°F-75°F)
Wet Bulb Reset
(60°F-75°F)65°F Fixed 65°F Fixed
Tower Fan VFD One Speed FanVFD on TWRS 4
&5One Speed Fan
VFD on TWRS 4
&5
VFD on TWRS 4
&5
VFD on TWRS 4
&5
VFD on TWRS 4
&5
CW Pump Control CV CV CV CVVFD Auto (100%
to 33% Min)VFD Manual (80%) VFD Manual (80%)
OA Reduction - Damper Retrofit (cfm/sf) 0.25 0.15 0.25 0.15 0.15 0.15 0.15
OA Reduction - DCV (cfm/sf) 0.15 0.12 0.15 0.12 0.12 0.12 0.12
High/Mid Fans18hrs / 5d (ON-
Time)
15hrs / 5d (ON-
Time)
18hrs / 5d (ON-
Time)
15hrs / 5d (ON-
Time)
14hrs / 5d (ON-
Time)
14hrs / 5d (ON-
Time)
14hrs / 5d (ON-
Time)
General Exhaust & Toilet Exhaust Fans24hrs / 7d (ON-
Time)
19hrs / 7d (ON-
Time)
24hrs / 7d (ON-
Time)
19hrs / 7d (ON-
Time)
20hrs / 7d (ON-
Time)
20hrs / 7d (ON-
Time)
20hrs / 7d (ON-
Time)
York Chiller
Curves
York Chiller
Curves
Chiller Plant - High
Loop
York Chiller
Curves
York Chiller
Curves
Condenser Water
System
Typical Floor AHUs
(Office)
York Chiller
Curves
Empire State Building Performance Year 4 M&V Report
Appendix 6: Baseline Adjustments 69
Appendix 6: Baseline Adjustments
List of 2014 Baseline Adjustments
The list of Baseline adjustments made in the model is shown below.
2014 weather
2014 utility analysis
2014 construction floors
2014 construction floor space temperatures
2014 tenant vacancy
2014 tenant space temperatures
2014 broadcast floors electric load
2014 variable air volume AHU upgrades
Weather Data
Baseline adjustments were made to incorporate 2014 New York City weather data.
Utility Analysis
Utility rates were updated in the model to reflect 2014 contract utility rate and 2014 actual utility rate. The data is shown in Appendix 7 of this Report.
Construction Floor Data
Floors under construction have elevated space temperatures during winter and, the HVAC electric loads and cooling loads are turned off during summer. The list of floors that were under construction in 2014 is shown below.
Floors under construction during first half of 2014:
3, 6, 10, 15, 16, 17, 18, 19, 20, 21, 29, 30, 31, 35, 39, 45, 49, 54
Floors under construction during second half of 2014:
3, 6, 10, 28, 29, 42, 49, 52, 54, 55, 56, 57, 60, 62
Empire State Building Performance Year 4 M&V Report
Appendix 6: Baseline Adjustments 70
Construction Floor Space Temperature Analysis
BMS wiring is cut off in most construction floors. Therefore, the space temperature data for most construction floors could not be recorded in the BMS. However, the data is available for a few construction floors and a sample is shown in Figure A-6.1.
Figure A-6.1: 29th Floor Space Temperature vs Time
Tenant Vacancy Analysis
PY building occupancy data was provided by ESB’s leasing agent. Actual move-in and move-out dates from the monthly plan book were utilized to accurately calculate the vacancy rate of the building. The following calculation method was utilized to estimate floor level vacancy rate:
Floor (n) Vacancy Rate (%) = (Total Vacant SF on Floor (n)) / (Total SF on Floor (n))
Where, (n) represents a specific floor.
The monthly averages were used to calculate the total annual average vacancy per floor. The annual average vacancy rates were then used to determine an overall average vacancy rate per CHW zone based on average level vacancy rates and modeled usable square footages per level. The low CHW zone serves the concourse level through Level 5, the mid CHW zone serves Levels 6 through 41, and the high CHW zone serves Levels 42 through 103. Based on the total annual average per CHW zone, an annual vacant square footage is determined.
Vacancy rate was applied to the "modeled tenant SF" and the resulting vacant spaces were setback. Non-tenant SF (=Total SF –Tenant SF) was assumed to be conditioned, but not setback.
Empire State Building Performance Year 4 M&V Report
Appendix 6: Baseline Adjustments 71
Johnson Controls physically measured all the floor spaces in ESB and calculated the total building SF to be 2,575,565 SF (this includes tenant space, corridors, mechanical rooms, elevator shafts, stairwells, etc.). The plan book shows that, as much as 2,070,966 SF is used as tenant spaces. These numbers compares closely with the modeled square feet which were based on building floor plans.
A number of modeled levels are assumed to be vacant to match this annual vacant square footage, which is indicated by the highlighted floors in the tables on the following pages. The vacant levels are modeled with no tenant loads and are assumed to have 24/7 HVAC setbacks in the tenant areas, as well as the corridors, restrooms, and building core support spaces on the vacant levels. The occupied tenant SF, elevator shaft, corridors and stairwells are all setback per the AHU supply fan schedule. Orange rows indicate floors modeled as construction floors.
Figure A-6.2 shows the detailed vacancy rate calculations.
Empire State Building Performance Year 4 M&V Report
Appendix 6: Baseline Adjustments 72
Empire State Building Performance Year 4 M&V Report
Appendix 6: Baseline Adjustments 73
Figure A-6.2: 2014 Vacancy Rate Calculation
Empire State Building Performance Year 4 M&V Report
Appendix 6: Baseline Adjustments 74
Tenant Space Temperature Analysis
Space temperatures from several floors were sampled and the resultant average space temperature used in the model is shown in the Figure A-6.3.
Cooling Season Heating Season
Space Type
Weekday Occupied Space
Temperature (°F)
Weekday Unoccupied
Space Temperature
(°F)
Weekend Space Temperature
(°F)
Weekday Occupied Space
Temperature (°F)
Weekday Unoccupied
Space Temperature
(°F)
Weekend Space Temperature
(°F)
Leased 72.5 73.9 75.7 74.1 70.9 69.4
Vacant 73.9 75.2 75.7 69.2 68.3 66.2
Construction HVAC Off HVAC Off HVAC Off 82.0 82.0 82.0
Figure A-6.3: Average Tenant Space Temperatures
Broadcast Floors Electric Load Data
The broadcast floor electric load in the model was updated using the 2014 data shown in Figure A-6.4.
Figure A-6.4: Broadcast Floor Electric Demand
Empire State Building Performance Year 4 M&V Report
Appendix 6: Baseline Adjustments 75
VAV AHU Upgrades
Several constant volume AHUs in the building were upgraded to VAV AHUs in the past few years. The list of upgraded AHUs is shown in Figure A-6.5 and the model was updated to reflect the upgrade. Note that the AHU name reflects the floor number and unit number. For example, AHU-15-4 denotes unit number 4 installed on the 15th floor.
Figure A-6.5: List of VAV AHU Upgrades
Empire State Building Performance Year 4 M&V Report
Appendix 7: ESB Utility Rates 76
Appendix 7: ESB Utility Rates
2007
Actual Rate
2011 Actual Rate
2012 Actual Rate
2013 Actual Rate
2014 Actual Rate
2014 Modeled
Rate
Customer Charge ($/day) $2.13 $2.13 $2.13 $2.59 $3.39 N/A
Energy Charges $/kWh $0.13 $0.13 $0.13 $0.11 $0.11 $0.17
G&T Demand $/kW $8.00 $8.00 $6.43 $8.42 $8.39 $6.35
Primary Demand (June - Sep) $/kW $14.97 $14.97 $17.80 $15.86 $15.81 $11.79
Secondary Demand (June - Sep) $/kW $16.06 $16.06 $19.55 $16.96 $16.90 $13.30
Primary Demand (October - May) $/kW $11.04 $11.04 $11.04 $11.98 $11.71 $8.73
Secondary Demand (October - May) $/kW $5.15 $5.15 $5.15 $5.73 $5.51 $4.23
Figure A-7.1: Baseline and Performance Period Electric Utility Rate Comparison
2007
Actual Rate 2008
Actual Rate 2014
Modeled Rate
Monthly Charge $/month $2,722.18 $2,722.18 $2,976.33
General Demand Charge $/therm/hr $10.526 $10.526 $11.51
Steam Demand Peak $/therm/hr $99.62 $99.623 $108.92
Summer Steam Consumption
First 2,500 Mlb $/therm $2.176 $2.176 $2.38
Next 7,500 Mlb $/therm $2.428 $2.428 $2.65
All additional Mlb $/therm $2.363 $2.363 $2.58
Winter Steam Consumption
First 2,500 Mlb $/therm $2.187 $2.187 $2.39
Next 12,500 Mlb $/therm $3.226 $3.226 $3.53
Next 35,000 Mlb $/therm $3.106 $3.106 $3.40
Next 200,000 Mlb $/therm $3.044 $3.044 $3.33
All additional Mlb $/therm $2.953 $2.953 $3.23
Swing Steam Consumption
First 2,500 Mlb $/therm $2.275 $2.275 $2.49
Next 12,500 Mlb $/therm $3.661 $3.661 $4.00
Next 35,000 Mlb $/therm $3.500 $3.500 $3.83
Next 200,000 Mlb $/therm $3.418 $3.418 $3.74
All additional Mlb $/therm $3.297 $3.297 $3.60
Figure A.7.2: 2007 Actual, 2008 Actual and 2014 Modeled Steam Utility Rate Structure
Empire State Building Performance Year 4 M&V Report
Appendix 7: ESB Utility Rates 77
2011 Actual
Rate 2012 Actual
Rate 2013 Actual
Rate 2014 Actual
Rate
Customer Charge $/day $207.71 $232.90 $254.95 $241.67
Winter All-time Peak Demand Charge (Applied all time during December to March) $/Mlb/hr
$151.03 $170.03 $193.26 $182.46
Winter On-peak Demand Charge (Applied 6 a.m.to 11 a.m. during December to March) $/Mlb/hr
$1,453.87 $1,636.71 $1,860.01 $1,755.71
Summer (May to October) Steam Energy Charge (for all additional Mlb) $/Mlb
$16.70 $15.19 $18.51 $14.71
Winter (December to March) Steam Energy Charge (for all additional Mlb) $/Mlb
$32.42 $32.35 $31.82 $28.17
Swing (April and November) Steam Energy Charge (for all additional Mlb) $/Mlb
$35.68 $34.02 $36.83 $34.39
Note: All consumption charges include GRT, MTA, state and city taxes
GRT and MTA taxes 2.48% 2.81% 2.65% 2.37%
State and City Taxes 8.88% 8.88% 8.88% 8.87%
Figure A.7.3: 2011 through 2014 Steam Utility Rate Structure
Empire State Building Performance Year 4 M&V Report
Glossary 78
Glossary
Acronym Definition
ADX Application and Data Server
AEM Automated Enterprise Management
AHU Air-Handling Unit
ARI Air-Conditioning and Refrigeration Institute
ASHRAE American Society of Heating, Refrigerating, and Air-Conditioning Engineers
ASTM American Society for Testing and Materials
ATI Architectural Testing, Inc.
BMS Building Management System
cfm cubic feet per minute
CH Chiller
CHW Chilled Water
CHWRT Chilled Water Return Temperature (building to chiller)
CHWST Chilled Water Supply Temperature (chiller to building)
CT Cooling Tower
CTWET Cooling Tower Water Entering Temperature
CTWLT Cooling Tower Water Leaving Temperature
Cv Coefficient of Variation
CW Condenser Water
CWET Condenser Water Entering Temperature (entering the chiller)
CWLT Condenser Water Leaving Temperature (leaving the chiller)
CWST Condenser Water Supply Temperature (to the chiller)
DCV Demand Control Ventilation
DDC Direct Digital Control
DOE Department of Energy
ECM Energy Conservation Measures
EPC Energy Performance Contract
ESB Empire State Building
FPI Facility Performance Indexing
gpm gallons per minute
GRT Gross Receipts Tax
HVAC Heating, Ventilating, and Air-Conditioning
IG Insulated Glass
Empire State Building Performance Year 4 M&V Report
Glossary 79
IPLV Integrated Part-Load Values
IPMVP International Performance Measurement and Verification Protocol
ISO International Organization for Standardization
M&V Measurement and Verification
MBE Mean Bias Error
Mlb 1000 lb
MTA Metropolitan Transportation Authority
NAE Network Automation Engines
NFRC National Fenestration Rating Council
OAT Outside Air Temperature
PFHX Plate and Frame Heat Exchanger
ppm parts per million
PY Performance Year
RIB Relay in a Box
RMSE Root Mean Square Error
SF Square Feet
SHGC Solar Heat Gain Coefficient
TEM Tenant Energy Management
UPS Uninterruptible Power Supply
VFD Variable Frequency Drive
VSD Variable Speed Drive
Empire State Building Performance Year 4 M&V Report
Report Delivery Acknowledgement
Report Delivery Acknowledgement
Empire State Building and Johnson Controls here by acknowledge that the Performance Year 4 (January 2014 to December 2014) Annual Energy Report was delivered on April 2, 2015.
Empire State Building:
Signature: ____________________________
Name: _______________________________
Title: ________________________________
Date: ________________________________
Johnson Controls:
Signature: ____________________________
Name: _______________________________
Title: ________________________________
Date: ________________________________
Empire State Building Performance Year 4 M&V Report
Report Completion Acknowledgement
Empire State Building and Johnson Controls here by acknowledge that the Performance Year 4 (January 2014 to December 2014) Annual Energy Report was completed as required by the energy performance contract and Empire State Building here by accepts the report.
Empire State Building:
Signature: ____________________________
Name: _______________________________
Title: ________________________________
Date: ________________________________
Johnson Controls:
Signature: ____________________________
Name: _______________________________
Title: ________________________________
Date: ________________________________