ASHRAE Journal - November 2021 - 30

ROUNDTABLE
Status of Standards Discussed in
This Roundtable
* UL 60335-2-40, Standard for Household And Similar
Electrical Appliances-Safety-Part 2-40: Particular Requirements
for Electrical Heat Pumps, Air-Conditioners and
Dehumidifiers
Rodgers: The fourth edition of UL-60335-2-40 is
currently out for preliminary review. It received well
over 700 review comments. The committee's goal is
to publish the standard in the early third quarter of
2022 and to make a proposal to the building codes
that the fourth edition go into 2024 building codes.
* UL 60335-2-89, Household and Similar Electrical
Appliances - Safety - Part 2-89: Particular Requirements for
Commercial Refrigerating Appliances with an Incorporated
or Remote Refrigerant Unit or Compressor
Rodgers: This standard was scheduled to be published
October 27, 2021.
* ASHRAE Standard 15-2019, Safety Standard for
Refrigeration Systems
Tharp: Several addenda to this standard have
been published already. The standard does allow
for A2L refrigerants today, but as noted elsewhere
during the roundtable, the current requirements
are more restrictive than UL 60335-2-40, 3rd edition
and UL 60335-2-89, 2nd edition. A couple of
states do reference the current Standard 15-2019.
As mentioned, there are several addenda that have
been published, and several more that are on the
way. For Standard 15 itself, most of those addenda
are expected to be published within roughly a year
or so aligning with the publication of UL-60335-240's
4th edition.
* ASHRAE Standard 15.2P, Safety Standard for Refrigeration
Systems in Residential Applications
VerShaw: This proposed standard has undergone
three public reviews and an advisory public review.
It is about to undergo a fourth more focused review,
which we plan to be the last review before publishing
late this year or early 2022.
Once Standard 15.2P is published, then the residential
coverage will be removed from Standard
15; then Standard 15 will cover commercial and
Standard 15.2P will cover residential fixed systems.
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ASHRAE JOURNAL ashrae.o rg N O V E M B E R 2021
charge of the system, but what is releasable in the event
of a leak.
Rodgers: Let me interject, the AHRTI 9015 report was
accepted recently and is now published on the AHRI
website under Research. That project looked at the mitigation
strategies in UL 60335-2-89 and in UL-60335-240,
and it verified our mitigation strategies.
Jennifer Butsch: Overall, both UL 60335-2-89 and UL
60335-2-40 have been updated to incorporate the safe
use of A2Ls and, relative to the commercial refrigeration
side, A3s. In particular most of these standards updates
focus on mitigation and safety measures designed to
prevent conditions needed to have a flammable event.
In both cases there is recognition that to have a flammable
event you need to be somewhere between the
lower flammability limit and the upper flammability
limit. So, if we can prevent that from occurring, then
there would never be a situation in which a flammable
event could occur. In both cases these safety standards
are replacing existing standards to which equipment is
certified today. So, although this conversation focuses
around A2Ls, and flammable refrigerants in general,
both standards updates took into account mechanical
and electrical requirements that needed to be pulled
over from other standards as well.
Kujak: Jim VerShaw, do you want to jump into the
discussion?
Jim VerShaw: Some of the things you're going to notice
as you start installing equipment with A2Ls is that the
refrigerant bottles service techs are going to be using will
have left-handed threads on them. Then some systems
will require refrigerant detection systems. Those are
probably the bigger differences they're going to see on
the servicing side from what they're dealing with currently.
Most installations in the past had to be checked to
meet RCL (refrigerant concentration limit). But usually
it wasn't calculated (for residential applications) because
it was so hard to hit that level that it wasn't important to
do so.
With A2L refrigerants, the installer's going to have to
understand how much refrigerant can be released into
the space, and how big the room size is, to see if there
is a leak it will hit the maximum refrigerant concentration
levels or not. That's going to be determined after the
system is fully charged up. Not until that point will they
know the total releasable charge, and then they can calculate
how close the installed system is to the maximum
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ASHRAE Journal - November 2021

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