New Approaches to Slash Commercial & Healthcare Building Energy - PowerPoint PPT Presentation

New Approaches to Slash Commercial & Healthcare Building Energy Use & Improve IEQ Grand Mosque, Mecca New Apple HQ ASHRAE HQ, Atlanta MGM Macau Casino Amazon ASU Biodesign Institute Spheres Workspace Gordon P. Sharp, Aircuity

Overview For Airside Efficiency Savings Overview & introduction Demand Control Ventilation (DCV)  Research on DCV effectiveness and problems  “Healthy” DCV & the WELL Standard Multiplexed sensing: A better sensing approach DOAS DCV Case studies Healthcare 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: Control Approaches:  Human pollutants  Furnishings selection  Non Human Pollutants  Green cleaning, etc.  Filtration IEQ & Energy Efficiency Performance Outside Air Ventilation: Control Approaches:  Source dilution  Demand Control Ventilation (DCV) How do we optimize & validate ventilation performance for health and energy efficiency?

ASHRAE Standards Provide a Solution ASHRAE 62.1 provides for dynamic reset control  Specifically refers to Demand Control Ventilation (DCV)  Carbon dioxide (CO2) sensing typically used for DCV ASHRAE 189.1 Requires DCV for > 25 people/1k ft 2  For spaces >500 ft 2 but also some exempted systems ASHRAE 90.1 Green bldgs std. now same as 90.1  Requirements changed from > 40 to >25 people/1k ft 2

So What about Demand Control Ventilation? Measures the rise of CO2 in the building  Measures amount of ventilation  CO2 is a good proxy for human pollutants Reduces ventilation when occupancy drops  Can save substantial energy when loading varies  Even 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* CO 2 Field Sensor Study Paper Results 10% Dead 81% Read High 9% Low (avg. 39%!) (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 Outside Air CFM Error % of Required 400% 350% 300% 250% 200% 150% 100% 50% 7% 27% 0% 64% -50% Average Over-Ventilation >20% OA Error ≤20% OA Error Average Over-Ventilaton -100%

CO 2 Sensor Study Results - Iowa Energy Center 15 Models – 13 Manufacturers 2 models - 2/3 units met factory spec 4 models - 1/3 units met factory spec 9 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&D  Similar in concept & related to LEED Standard  Rapidly gaining traction: ~300M ft 2 in progress  New Version 2 came out in May 2018 WELL promotes good air quality & monitoring  Recommends 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!

Multiplexed Sensing Operation Supply Air Duct Break room 101 Large office 102 Conference 103 Room Sampling Outdoor Air Duct Probe Port (RS) Return/ Exhaust Duct Air Data Sensor Router Suite with TVOC, CO2, Information Dewpoint & Management Particulate Server sensors Advisor Connectivity Data Center Web User Interface Vacuum To BMS Pump

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. 5 Periodic 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 Cost DCV with DOAS means air tracks occupants  Allows 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 DOAS Example: 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 ft 2

Well Standard Version 2 – IEQ Monitoring Tighter from an IEQ Monitoring standpoint  Requires 4 of 7 parameters: – PM2.5 or PM10, CO2, CO, TVOC, NO2, Ozone, Formaldehyde  Requires sensing every 3500 ft 2  At least annual sensor calibration or replacement  More requirements on accuracy & sensing time Still has credit for display or web data feedback  Sensor data needs to be accurate to provide peace of mind about IEQ.

Case Study – LEED & Office DCV Projects One Bryant Park  World’s largest, most green skyscraper – Also known as Bank of America Tower – 2 nd 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