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New Approaches to Slash Commercial & Healthcare Building Energy Use & Improve IEQ
ASHRAE HQ, Atlanta
Gordon P. Sharp, AircuityMGM Macau Casino
Grand Mosque, MeccaNew Apple HQ
ASU Biodesign InstituteAmazonSpheres Workspace
Overview For Airside Efficiency Savings
Overview & introductionDemand Control Ventilation (DCV)Research on DCV effectiveness and problems “Healthy” DCV & the WELL Standard
Multiplexed sensing: A better sensing approachDOAS DCVCase studiesHealthcare applications
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!
IEQ – Energy Dynamics of Green Buildings
Contaminant sources: Human pollutants Non Human Pollutants
Outside Air Ventilation: Source dilution
Control Approaches: Furnishings selection Green cleaning, etc. Filtration
Control Approaches: Demand Control
Ventilation (DCV)
How do we optimize & validate ventilation performance for health and energy efficiency?
IEQ & Energy Efficiency Performance
ASHRAE Standards Provide a Solution
ASHRAE 62.1 provides for dynamic reset controlSpecifically refers to Demand Control Ventilation (DCV)Carbon dioxide (CO2) sensing typically used for DCV
ASHRAE 189.1 Requires DCV for > 25 people/1k ft2
For spaces >500 ft2 but also some exempted systems
ASHRAE 90.1 Green bldgs std. now same as 90.1 Requirements changed from > 40 to >25 people/1k ft2
So 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
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
New WELL Building Standard promotes full IEQ monitoring and is putting more focus on building IEQ and wellness
New WELL Building Institute Standard
International WELL Building Institute (IWBI):Leading the movement to promote health and
wellness in buildings and communities everywhere.WELL Building Standard:Launched in October 2014 after six years of R&DSimilar in concept & related to LEED StandardRapidly gaining traction: ~300M ft2 in progressNew Version 2 came out in May 2018
WELL promotes good air quality & monitoringRecommends continuous monitoring of air quality
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
IEQ monitoring helps meet new WELL Bldg. Std. Credit v1: Monitoring of CO2 & Particles (2 of 3) Credit v2: Now 4 parameters CO2, CO, TVOC, particles (4 of 7)
Vary outside air rates based on actual air cleanliness to provide a
superior indoor environment!
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
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.”
January, 2016 ASHRAE Journal Article
“Locations and Installation of Sensors and Their Accuracy” “CO2 sensors are subject to calibration
drift and accuracy issues over time. A field study on a campus building with CO2- based DCV found that differences between the commercial CO2 sensors used in buildings are significant.5Periodic maintenance is essential to keep the readings of CO2 concentration accurate over time.”
“Since the difference between primary air and zone air CO2 concentrations may be very small, sensor accuracy is critical. A system that uses a single sensor with multiple air-sampling ports would likely result in the most accurate CO2 readings, provided sampling times are reasonably short. A system with separate zone air and primary air sensors would likely result in the least accurate CO2 readings.”
DCV & Dedicated Outside Air Systems (DOAS)
DOAS provides 100% OA direct to room, no return air DOAS decouples cooling & ventilation requirements DOAS is usually more energy efficient than VAV
Local room cooling loads are covered by: Geothermal Heat Pumps Chilled beams and chilled ceilings Variable Refrigerant Volume & Flow (VRV & VRF) Systems
DCV and DOAS are highly synergistic DCV controls fresh air ventilation needs Fan power, heating & cooling is reduced Exception: areas with high % of free cooling
DOAS Using DCV Also Cuts First CostDCV with DOAS means air tracks occupantsAllows design to number of occupants vs. spaces
– Natural diversity of space usage reduces HVAC requirements– Applicable where the spaces are served by same AHU
Fixed OA – wastes energy & requires larger DOASExample: Schools have many duplicate spaces Over 75 US schools have downsized DOAS by 67%!
Example: Offices: open offices & meeting rooms
WELL Building Standard Promotes These Concepts
WELL building standard version 1 & 2 supports:Demand Control Ventilation (DCV)
– Multiple points for control of fresh air via CO2 based DCV– Possible additional Innovation & Design points for Healthy DCV
DOAS – Dedicated Outdoor Air Systems– Credits in both Air and Thermal Comfort sections for DOAS
Full IEQ Monitoring – Points for both monitoring and displaying IEQ data to occupants
WELL Standard Version 1 IEQ Monitoring
Feature 18: Air Quality Monitoring & Feedback:Part 1: Indoor Air Monitoring:
– Monitor two of CO2, PM2.5 particles or ozone.
Part 2: Air Data Record Keeping and Response– Requires data to be stored for at least 3 years– Also a plan for action and remediation of unacceptable conditions
Part 3: Environmental Measures Display– Requires a real time IEQ information display for occupants every
10K ft2
Well Standard Version 2 – IEQ Monitoring
Tighter from an IEQ Monitoring standpointRequires 4 of 7 parameters:
– PM2.5 or PM10, CO2, CO, TVOC, NO2, Ozone, Formaldehyde
Requires sensing every 3500 ft2
At least annual sensor calibration or replacementMore requirements on accuracy & sensing time
Still has credit for display or web data feedbackSensor data needs to be accurate to provide peace of
mind about IEQ.
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– Approach 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
Case Study – Apple Campus 2
~ 3 million sq. ft., over 2000 sampling pointsOne mile around circumference – visible from space
Natural ventilation controlled by CO2 sensingOutside air brought in & mixed with conditioned air
Remote sensors increases “Apple security”
Shamiya Expansion of the Grand Mosque
Healthy DCV will be controlling millions of OA CFM IEQ monitoring CO2, CO, TVOC, Particles, RH, & T
Shamiya Bldg. will hold over 500,000 people.Healthy DCV also designed into renovation of existing GM
Hospital Spaces where Flows can be Reduced w/ DCV
Great applications:Areas with variable use
– Operating Rooms– Outpatient Admin areas– Waiting Rooms– Lounges– All others
Less applicable: SSPC 170 24 hour & regulated spaces
– Administration, Emergency– Pharmacy– ICU– Patient Rooms
Operating Room Demand Control Approach
Case Study of Operating Room DCV Sensing 18 ORs, corridor, & outside air
– Particles, Dewpoint/RH, TVOC’s, CO2, CO, T
Successful pilot of demand control– OR operated with demand control in Unocc mode
Occupied mode for operations & setup:– Full flow, normal levels per 170 guidelines
Demand control mode for Cleanup & Unocc:– Much lower minimum flow setpoint– Min Flow level can be increased or overridden by:
• High particle levels, TVOC’s, or temperature
Result: Significant Energy Savings, Clean Air & Great IEQ
Operating Room Data - Particles
Operating Room Data - Particles
Operating Room Data – CO2
Operating Room Data – TVOC’s
Another OR Case Study: Memorial Sloan Kettering
A large cancer center and hospital facilityEnergy retrofit of 21 operating roomsEnergy savings results: 1.5 year paybackAlso improved IEQ and assured air was clean
DCV & Multiplexed Sensing Summary
DCV done correctly can increase savings & IEQ: Use multiplexed sensing to solve sensor accuracy issues
– Much less sensors and differential sensing: cost effective & accurate
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]