ASHRAE Journal - May 2024 - 14

COLUMN IEQ APPLICATIONS
uses ultraviolet and a metal
catalyst to break up contaminants
that strike the catalyst surface. In
favorable cases, the end result is
a mixture of carbon dioxide and
water.
* Photocatalytic devices (also
called PCO) that put reactive
species into the air.
* Ionizers of various sorts, which
FIGURE 2 Media filter impregnated with carbon to catch both particles and volatile
organic compounds.
to be tested for contaminant
removal efficiency. This test will
make it easier for RACs to be used
for both LEED certification and
IAQP design.
produce airborne ions including
charged particles and charged
chemical species.
Many types of these devices exist with differing
levels of research showing how they work. Also, the
terms used to describe them often change and can
vary among different devices using the same or similar
technology. Extensive literature on RACs exists, but
most is exploratory and little of the peer-reviewed work
on the topic is based on devices that are currently for
sale.3 These issues point to the need for TC 2.3, Gaseous
Air Contaminants and Gas Contaminant Removal
Equipment-the cognizant technical committee for
Standard 145.1 and Standard 145.2-and other interested
parties to look further into the subject of RACs.
In response to the U.S. Green Building Council
(USGBC) requiring that all technologies used for gaseous
contaminant removal in Leadership in Energy and
Environmental Design (LEED) buildings be tested using
Standard 145.2, Laboratory Test Method For Assessing the
Performance of Gas-Phase Air-Cleaning Systems: Air-Cleaning
Devices, SSPC 145 has rewritten the standard to enable
testing of RACs in addition to sorbent-based air cleaners.
In addition to the need from the USGBC, ASHRAE
Standard 62.1 has an Indoor Air Quality Procedure
(IAQP) that allows building owners to use actual air
quality to determine the amount of outdoor air needed.
Since air cleaners can be used to reduce concentrations
of designated contaminants and allow less outdoor air to
be pulled into the buildings, resulting in energy savings
due to lower heating and air cooling requirements, it has
become important to allow RACs to be tested for removal
efficiency and potential use in the IAQP.
The revised Standard 145.2 is currently going
through public review. When published, it will allow
all or most HVAC-mounted air cleaners that remove
gaseous contaminants inside or very near the device
14
ASHRAE JOURNAL ashrae.org MAY 2024
Because some RACs remove
gaseous contaminants from the
room air rather than air inside
the air cleaner, TC 2.3 authorized,
and SSPC 145 stepped up to
write, the proposed Standard
145.4 test method that will cover
RACs and other devices that need to be tested with
room air contaminant monitoring. This test will
give us efficacy results similar to the Association of
Home Appliance Manufacturers (AHAM)'s standard,
AHAM-AC-4-2022.4 It includes what AHAM calls the
c-CADR (chemical clean air delivery rate) but for
devices that need to be mounted in a duct or have
duct air circulation to function, compared to the
method for in-room cleaners. This will allow those
concerned with gas-phase contaminants in the air a
full slate of tests to help determine which air cleaners
can be successfully applied to reduce contaminants in
most occupied spaces.
The air cleaners discussed above can be useful in
a variety of building settings to reduce contaminant
concentrations and odors. These include, but are not
limited to, indoor sources such as furniture emissions,
cooking odors and cleaning product emissions and
outdoor sources such as vehicle emissions, smokestack
emissions and wildfire gases that can enter through the
air intake or by infiltration.
In conclusion, you can effectively reduce odors and
other gas-phase contaminants, but you need to use an
air cleaner that is intended (and tested) to address gases,
sometimes even a specific gas or gases.
References
1. ASHRAE Standard 145.1-2015, Laboratory Test Method for Assessing
the Performance of Gas-Phase Air-Cleaning Systems: Loose Granular Media.
2. ASHRAE Standard 145.2-2016, Laboratory Test Method for Assessing
the Performance of Gas-Phase Air-Cleaning Systems: Air-Cleaning Devices.
3. Owen, K.O. 2023. " Emerging Gas-Phase Electronic Filtration
Technologies and ASHRAE 145.2 Test Standard. " ASHRAE Research
Project RP-1838. Final Report.
4. AHAM. 2022. " AHAM AC-4-2022 (Chemical Reduction): Method
of Assessing the Reduction Rate of Chemical Gases by a Room Air
Cleaner. " Association of Home Appliance Manufacturers. https://
tinyurl.com/4h2px7f2
http://tinyurl.com/4h2px7f2 http://tinyurl.com/4h2px7f2 http://www.ashrae.org
ASHRAE Journal - May 2024

Table of Contents for the Digital Edition of ASHRAE Journal - May 2024
