new approaches to slash building energy & improve indoor environmental...
TRANSCRIPT
New Approaches to Slash Building Energy & Improve Indoor Environmental Quality
Richardsville Elementary: 1st net-zero school
Richardsville Elementary: 1st net-zero school Bank of America
Largest LEED Plat.
ASHRAE HQ, Atlanta
Gordon P. Sharp, AircuityMGM Macau Casino
Grand Mosque, Mecca
Presentation Overview For Building Energy Savings
Overview & introduction – net zero facilitiesDemand Control Ventilation (DCV)Research on DCV effectiveness and problems “Healthy” DCV
Multiplexed Sensing: A better sensing approachDCV & DOAS DCV case studiesDemand Based Control (DBC) for laboratoriesLaboratory energy analysis & case studies
Goal: Dramatically Reduce Building Energy Use
Outside air: Largest energy & IEQ driver Reducing OA reduces many energy uses
New technologies can help: “Healthy DCV” via Multiplexed Sensing Demand Based Control of lab ACH rates
New codes/standards are supportive New versions of ASHRAE, NFPA 45, others
Result: Dramatic cut in energy use Better IAQ & lower building energy use Labs can often run as low as 2 ACH
If these approaches are used even a Net Zero lab is possible, although many would call that
not just mission difficult but: Mission Impossible!
Applications for Classroom, Offices, & Other Spaces
Optimize Building Ventilation Control
Room/Zone LevelAirflow Control
Building/AHU LevelOutside Air Control
Conventional DCV & Healthy DCV
What about Demand Control Ventilation?
Measures the rise of CO2 in the buildingMeasures amount of ventilationCO2 is a good proxy for human pollutants
Reduces ventilation when occupancy dropsCan save substantial energy when loading variesEven optimizes the ventilation for constant loading
– Most buildings are designed with more air than normally needed
Is DCV a good approach then for saving energy while also improving and validating IEQ?
LBNL* CO2 Field Sensor Study Paper Results10% Dead
81% Read High(avg. 39%!)
9% Low(½ by 50%)
No trends observed with 44 sensors vs site, mfg, or age!
* Lawrence Berkeley National Laboratory: Operated by the University of California for the U.S. Department of Energy
Typical DCV Performance Based on LBNL
-100%
-50%
0%
50%
100%
150%
200%
250%
300%
350%
400%
>20% OA Error ≤20% OA Error Average Over-Ventilaton
Outside Air CFM Error % of Required
64%
27%7%
Average Over-Ventilation
CO2 Sensor Study Results - Iowa Energy Center
15 Models – 13 Manufacturers2 models - 2/3 units met factory spec4 models - 1/3 units met factory spec9 Models - 0/3 units met factory spec
New LBNL CO2 Study of 165 sensors in 25 bldgs
Summary of report: “Together, the findings from the laboratory studies of the Iowa Energy
Center and current field studies indicate that many CO2 based demand controlled ventilation systems will fail to meet the design goals of saving energy while assuring that ventilation rates meet code requirements.”
“The Iowa Energy Center …recently released the results from a laboratory-based study of the accuracy of 15 models of new single-location CO2 sensors. ….Many of the new CO2 sensors had errors greater than 75 ppm, and errors greater than 200 ppm were not unusual. Maximum errors of new sensors approached 500 ppm.”
Forty seven percent of sensors had errors greater than 75 ppm at a concentration of 760 ppm and 40% of sensors had errors greater than 75 ppm at a concentration of 1010 ppm. A significant fraction of sensors have much larger errors, e.g., > 300 ppm. ..Thus, overall many CO2 sensors do not meet accuracy requirements.”
Indian ASHRAE Research plans to replicate LBNL study to validate results here in India with CO2 sensors
And Conventional DCV Concept is Also Flawed
DCV only solves half of the problem DCV varies O.A. based only on number of people in bldg
DCV does not react to non-human pollutants Odors, particles, CO, and formaldehyde
As a result: DCV can create complaints Nonhuman pollutants can rise when DCV reduces O.A.
– New bldg, recent renovation, cleaning materials, vacuuming
Typical response: Disable DCV & increase O.A. RESULT: Increased Energy Costs
Solution: Multi-parameter DCV or “Healthy” DCV
The goal is dilution of all pollutants in building:Human based pollutants (odors, virus, bacteria, etc.)Non human pollutants (TVOC’s, particles, CO, etc.)
Control O.A. based on multiple parameters:Use CO2 as a proxy for human based pollutants EPA & LEED specify levels for non-human pollutants
– TVOC’s, particles, & carbon monoxide
Sensing humidity also helpful to prevent mold
Vary outside air rates based on actual air cleanliness!
Break room 101 Large office 102 Conference 103
Supply Air Duct
Return/ Exhaust Duct
To BMS
Advisor Data Center
Outdoor Air
Air Data Router
Connectivity
Information Management
Server
Vacuum Pump
Room Sampling Port (RS)Duct Probe
Web User Interface
Sensor Suite with
TVOC, CO2, Dewpoint & Particulate
sensors
Multiplexed Sensing Operation
Sensed Parameters
Air CleanlinessTotal Volatile Organic Compounds
– Photo-Ionization Detector – Metal Oxide Sensor
Particles– Laser based particle counter
Carbon Monoxide (CO) Comfort & VentilationTemperature Humidity or DewpointCarbon Dioxide (CO2)
New LBNL Report also Tested Multiplexed Sensing
Summary of LBNL tests on Multiplexed Sensing “The study results illustrate the advantage of
incorporating a measurement of outdoor air CO2 concentration with each sensor – offset errors cancel out in the indoor minus outdoor CO2 concentration difference.”
Benefits of Multiplexed Sensing ConceptBetter total first cost Single high quality sensor cost for up to 20 locations Single point digital integration w/ building controls
Lower operating costs: Drastically reduced calibration cost
– One high quality sensor to calibrate vs. 20 sensors
Rental approach to sensors – No local maintenance !– Sensors are more accessible, can be swapped out for calibration– No replacement sensor costs during system life
Continuous M&V process for long term energy savings Web based data analysis facilitates real time commissioning
– System degradation can be easily observed and corrected
Cost effective, accurate bldg data for ventilation control
Goal: Save Energy by Turning Data into Information
What are Intelligent Agent Systems? Typically involves streaming building data to a website Intelligent agent software analyzes the data in real time
What can these systems do? Identify system anomalies and report back to operatorsAnalyze and help optimize system performance
How do these systems report issues? Summary Reports: Snapshot of system performanceDashboards – Graphically analyze ventilation, IEQ, etc.
HEPA FILTERSupply Air
Ongoing Commissioning – Why Overventilated?
What has changed?One or more spaces over/under ventilated
Thermal conditions have changedVentilation Mass balance has deviated from the norm– Does occupant density represent design?– Are occupants gathering where expected?
Another App: Comfort Zone Conformance Analysis
Evaluates Dry‐bulb Temperature & Relative Humidity
Scatter plots give a good idea of T and RH performance
IEQ Example: Monitor Fan Filter Integrity
Smart Notification triggers on abnormal particle levelsLevels on discharge of fan filters in two zones stand out
Suggests 1 filter has ruptured, & a 2nd is partially rupturedTechnicians can be deployed to minimize IEQ event
3rd Floor
Dedicated Outside Air Systems (DOAS)
DCV used to control OA to higher occupancy spacesThermal and cooling load decoupled Geothermal Heat Pumps Variable Refrigerant Volume (VRV) Systems Variable Refrigerant Flow (VRF) Systems
Numerous VRV / VRF Manufacturers
DOAS Application Using DCV (K-12)
DOAS provides ventilation requirementFixed OA – wastes energy & requires larger DOASControl OA via CO2 (DCV) – supports energy savings
AND can now take Diversity and Downsize DOAS Over 30 US schools have downsized DOAS by 67%!
– “When CMTA dissected the data further, it discovered that the outdoor air system was consuming half of the HVAC energy. The data led to changes in the outdoor air system to a variable flow, demand control ventilation system on the next WCPS project. “
-- ASHRAE High Performing Buildings Magazine – Fall 2009
Case Study – LEED & Office DCV ProjectsOne Bryant Park
World’s largest, most green skyscraper– Also known as Bank of America Tower
– 2nd tallest building in NYC – 1,250'
– $1.0 B, 2.1M sq. ft. building
LEED Platinum– Aircuity contributed points for CO2, IEQ
Cost effective IEQ monitoring & DCV – Total of over 800 locations monitored
Case Study – LEED & DCV Projects
ASHRAE Headquarters Renewal – LEED CI Platinum Humidity monitoring, DCV control
Sensing for AHU & Enthalpy wheel control
Helping ASHRAE realize its living laboratory goal
TVOC, particles, CO2, Dewpoint , T sensing throughout
Multi-parameter DCV Case Study: Arena
New Jersey Devils – Prudential Arena, Newark, NJ 100,000 sq. ft. sports arena; $310M budgetMulti-parameter DCV control: CO2, CO, particles, & TVOC’s Dewpoint sensing & control for “Best Ice in the NHL”
College/University Case StudiesAcadia UniversityArizona State Univ.Boston UniversityCal State UniversityCarnegie Mellon Univ.Case Western ReserveCentral CollegeColorado Sch. of MinesConcordia Univ.Dalhousie UniversityDartmouth CollegeDavenport UniversityFerris State University Grand Valley State Un.Harvard Law SchoolHarvard (HSPH & Law)Hastings CollegeKansas Univ.Michigan State Univ.
Montana State U.Midwestern Univ.MIST (Masdar Int.)MITNortheastern Univ.Ohio State Univ.Ohio Dominican U.Purdue UniversitySanta Monica Col.Univ. of Ca. IrvineUniv. of Las VegasUniv. of LouisvilleUniv. of MissouriUniv. of MontanaUniv. of N. TexasUCONNUPENNUniv. of WyomingYale University
MIT Sloan School Bldg
Yale Arts & Architecture
UPenn:“Demand Control of airflow is our #1 efficiency approach”
Other Commercial Building Case StudiesBank of America NC HQ.Boeing Corp.ASHRAE HeadquartersBristol Myers SquibbCrocker MuseumDial CorporationDurst, Bank of AmericaESPN – Disney Corp. Eli Lilly CorporationHarrah’s CasinoMohegan Sun CasinoMuscogee Creek CasinoNew Jersey Devils ArenaPNC – Pittsburgh, PAToronto Film FestivalUBS Financial USGBC HeadquartersVornado, 1 Penn PlazaVM Ware Data CenterXcel EnergyArmed Forces Reserve Ctr
Brigham & Women’s Hospital
Prudential Center, NJ Devils Arena
Ariz. State ArchivesBellevue Transit FacilityJ.W. Peck Federal Bldg
Joint Forces Nat’l GuardJuneau Maintenance Bldg King County Metro Base
Kodiak City Police StationLas Vegas City Mob Mus.Mecklenburg CourthouseMcCoy Federal Building
Nixon Presidential LibraryRockingham Judicial Ctr
Brigham & Women’s HospKaiser Permanente
Mount Nittany HospitalMunson Medical CenterNevada Cancer Institute
North Shore Hospital NYU Medical Center
Sloan Kettering Cancer St. Francis Care Hospital Nixon Pres. Library
Research Laboratory Energy Consumption
Lab Energy Usage:5 to 10 times office usage
For many universities:2.5 to 10% sq. footage10 to 40% site energy usage
>65 % of lab energy: HVAC
Achieving Down to 2 ACH Safely in Labs
Goal: Achieve 2 ACH day/night or 3-4 day /2 nightWhat are the drivers of lab airflow that affect this? Hood flows, thermal loads & ACH rates
Hoods Thermal Load
Demand Based Control of ACH
VAV Hoods
ACH / Dilution Requirement
VAV Supply
2 ACH Min
To achieve lab flows down to 2 ACH to reduce energy & 1st
cost, all flow requirements need to be reduced
Min Flow
Min Load
Reducing/Varying the ACH Rate Flow
Demand Based Control (DBC) solution Reduces lab airflow when lab air is “clean” Increases lab flow when pollutants sensed
Studies show lab air clean > 98% time Equal or better safety w/ the Best airflow A fixed min ACH flow is always to high or low When needed flow can be upped to 8-16 ACH
Clean flow setting of 4/2 ACH is typical 4/2 ACH best done as day/night vs. occ/unocc
– Using 3/2 ACH better & more cost effective– Clean flow of 2 ACH (even during day) is best
Demand Based Control (DBC) provides a safe means to achieve 2 ACH
Demand Based Control
ACH Requirement
2 ACH Min
ASHRAE Handbook Provides New Guidance
New 2011 ASHRAE Handbook, Lab chapter 16:Active/Demand Based Control is recommended:
– “Reducing ventilation requirements in laboratories and vivariums based on real time sensing of contaminants in the room environment offers opportunities for energy conservation.”
– “This approach can potentially reduce lab air change rates down safely to as low as 2 air changes per hour when the lab air is ‘clean’...”
New Delhi, India Example Analysis Assumptions
Model typical bldg. w/ 12.5K GSMLab & lab support area: 5.0K NSMOffice area: 3.0K NSM
Base dilution ventilation:Conservative 6 ACH baseline
Energy Cost, assumes true costElectric: $0.12/kWh Avg (6.4 INR/kWh)Heating: $1.00/therm (1.8 INR/kWh)
Low Fume Hood density:One 6’ FH/ 667 ft.2 module (75)
Manifolded exhaust fans: 4 fans are staged plus 1 spare
6 ACH Baseline Energy Costs For New Delhi
Cooling dominates energy use: 54% of totalSkin & solar gains typically small compared to OA
Total baseline energy use is 300 Lakh/ year
New Delhi DBC Energy Savings of 4 Day/2 Night ACH
Demand Based Control reduces lab HVAC energy by 146 Lakh or by 49% vs. 6 ACH. Payback is 2.0 years.
Lab Case Study: Arizona State UniversityASU Biodesign Institute Bldgs A & B Retrofit Retrofit of Labs and Vivarium
LEED® NC Platinum, R&D 2006 Lab of the Year (Bldg. B) Lab DCV pilot in 2007 to look for EE: 65% savings achieved Full building (A&B) retrofitted in 2009: $1 Million saved/year Currently 24 buildings have been retrofitted:
– Office, classroom, library, sciences bldgs, sports arena & others
0 CFM
2,000 CFM
4,000 CFM
6,000 CFM
8,000 CFM
10,000 CFM
12,000 CFM
14,000 CFM
16,000 CFM
18,000 CFM
May-17 May-24 May-31 Jun-8 Jun-15 Jun-22 Jun-29 Jul-6 Jul-16 Jul-23 Jul-30 Aug-6 Aug-13 Aug-20 Aug-27 Sep-3 Sep-11
Exhaust CFM Supply CFM
Average Savings: 10,757 CFMIn 11 Zones (~8,000 ft2)
At $5.14/CFM annually= $55,290 annually= $6.91/ft2 annually< 11 month payback!
Old Average Supply: 15,978 CFM
New Average Supply air : 5,221 CFM
June 4, 2007System
Activation
10,7
57 C
FM S
avin
gs
Pilot Study Results
Major Energy & Capital Impact for Near Zero Labs
Masdar City, Abu Dhabi - Largest net/near zero project Near zero emissions lab w/ Demand Control & chilled beams
– 150K m2 total, ~ 40K m2 of labs: MIST 1 A (Built) & 1B (Under const.)
Projected total energy savings: $2 M $ or 9,000 MWh /year – Labs operate at 2 ACH (day & night), purge up to 14 ACH
Downsized mechanical system to save HVAC capital costs Cuts solar PV capacity by ~ 3.75 MW or ~$20M first cost!
MIST 1A: 50K sq. m., 15K sq. m labs
First Cost Saving at Univ. of Houston
Health & Biomedical Sciences Center / Optometry 6 Floors, ~150K sq. ft, 71 labs, 37 vivariums & 24 non-lab zones
Lab & Vivarium flows reduced: Labs from 12 ACH to 4 ACH Vivariums from 15 ACH to 9 ACH
DBC Installed cost : ~ $500KEst. energy savings ~ $250K/ yr2.0 year payback: energy onlyFirst cost savings up to $1.0M!
DBC was a critical add to help bring project into budget
Laboratory/Vivarium Case StudiesAcadia UniversityAlbion College Arizona State UniversityBeth Israel Medical CenterBristol Myers SquibbChicago Botanic Garden Cal State Univ., Monterey Cal TechCase Western Reserve Univ.Colorado Sch. Of MinesChildren’s Hospital of Phil.Dalhousie Univ.Dartmouth CollegeEli LillyFerris State UniversityFood & Drug Admin. (FDA)Ferris State UniversityGrand Valley State UnivHarvard (HSPH)Indiana/Purdue Fort Wayne
Hastings CollegeLabCorp – BioRepositoryMasdar Institute, UAEMichigan State UniversityMidwestern UniversityMinistère de l’agriculture, Montreal Heart instituteNational Inst. of Health (NIH)Nevada Cancer InstituteOhio State UniversityOklahoma State UniversityRice UniversitySabanci University, TurkeyTexas Children’s HospitalUniversity of Cal IrvineUniversity of IowaUniversity of LouisvilleUniversity of Pennsylvania Univ. Health Network: MaRSVan Andel Institute
Univ. of Louisville: Bio Med 3
UPENN:Carolyn Lynch Lab
UPenn: FisherOver 200 lab building projects using DBC
DCV & Multiplexed Sensing Summary
DCV done correctly can increased savings & IEQ: Use multiplexed sensing to solve sensor accuracy issues Sensor “rental’ approach to solve maintenance concerns
DBC: Single greatest means to cut lab energyApplicable to new & existing building types Office buildings Classroom & Educational Lab & Vivarium Healthcare Public Assembly & Arenas
Questions?For a copy of the presentation, contact:
Gordon Sharp, [email protected]