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

New Approaches to Slash Commercial & Healthcare Building Energy Use & Improve IEQ

ASHRAE HQ, Atlanta

Gordon P. Sharp, Aircuity

MGM Macau Casino Grand Mosque, Mecca New Apple HQ

ASU Biodesign Institute

Amazon Spheres Workspace

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:

 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 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 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 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* CO2 Field Sensor Study Paper Results

10% 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 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 ft2 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!

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

• ut 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 ft2

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 ft2  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 – 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 points

 One mile around circumference – visible from space

Natural ventilation controlled by CO2 sensing

 Outside 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 facility Energy retrofit of 21 operating rooms Energy savings results: 1.5 year payback Also 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 energy Applicable 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, gsharp@Aircuity.com