ASHRAE Journal - November 2021 - 32

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allowable. That will determine whether or not a detection
system is needed for the system. These are the key
things that are going to be different in terms of what the
installer's going to have to look at.
From a manufacturer's viewpoint, a lot of things are
going to stay pretty much the same, except in the control
box where the contractors will be limited to how much
power they can transfer, so if a leak of refrigerant occurs,
it can't ignite the refrigerant and cause a fire. Overall,
the A2Ls, while they are more flammable than A1s, are
not explosive, and I feel that we've created standards
and installation instructions that will make these new
systems very safe and very reliable
Kujak: I've heard twice so far in the conversation that
we're pushing some requirements over to the installation
side, and we're going to have to look at the application
where we didn't before with the non-flame propagation
refrigerants. Is that a concern for people here?
Rodgers: Regarding the charge limit and the room
area size, we're helping the installers out by requiring a
label on some of this, especially as we talk about how UL
60335-2-40 covers room air conditioners, spot coolers,
those type of things. We're putting on there-based on
the charge, to install the product, in the minimum sized
room area-you've got to have at least this many square
feet to install this piece of equipment. So that's going to
help out, especially the consumer that buys these goods.
He's going to say, " Okay, I want an air conditioner for my
bedroom. " He'll be able to say, " Well, my bedroom's this
size, I need to do this to be safe. "
To help the consumer we have added Annex DD in UL
60335-2-40, which adds minimum requirements for the
installation and servicing of the equipment. One such
requirement is to mark the minimum room area that
the equipment can be installed in.
Grider: What Brian is saying is interesting because
in this situation we had a safety standard UL 60335-240,
which in some cases was leading the codes in the
development. A lot of the installation requirements
are still prevalent in this safety standard, but those are
being transferred over to installation standards such
as ASHRAE Standard 15 [Safety Standard for Refrigeration
Systems] and ASHRAE Standard 15.2P [Safety Standard for
Refrigeration Systems in Residential Applications] where they
belong.
Steve, your question was, " Is there concern about putting
some of these requirements on the installer? " In
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ASHRAE JOURNAL ashrae.o rg N O V E M B E R 2021
ASHRAE Standard 15, and in ASHRAE Standard 15.2P,
there has been a lot of discussion and consideration of
that very question. Concerns from the industry included
questions like, " Well, do we really want installers having
to do complex calculations in the field to determine
maximum charge limits based on the design of the occupied
spaces? " We needed to provide tools that will allow
them to quickly make these determinations.
So instead, from the certification standpoint, like
Brian said, we're looking at the installation requirements
as provided by manufacturers.
We're doing some of those calculations to verify room
areas and how the manufacturer's going to go about
putting the information out there in an easy way for the
installer to interpret and apply. But in the end, it's going
to come down to following the codes, like Standard 15
and Standard 15.2P, to see, " Is the product certified? "
Okay, it is. Now, how is it being applied per that installation
manual, which would dictate everything, like Brian
said.
VerShaw: In Standard 15.2P we're using tables instead
of equations to aid the installer to determine the installation
limitations when using A2Ls. And 15.2 has safety
factors built in. Brian mentioned the testing done in
AHRTI 9015, and that allowed us to relax some of the
safety factors such that you can get a little more charge
in a given room size. I think all of that is helping us be
less concerned about proper installation. Of course,
with any air-conditioning installation you're always concerned
that they got the duct sizes right, and they've got
the wiring done right, and they've got the piping done
right. That doesn't change. Here they must take that
extra step to understand the room sizes and the amount
of releasable charge.
Kujak: So, I know we've been talking about UL-603352-40.
Are these same practices and charge limits all the
same with UL 60335-2-89?
Grider: No, and that's intentional because the way
commercial refrigeration appliances are installed is different
than HVAC, and there are different code requirements
for egress and things like that, which have to be
considered as to where they're installed. Lobbies and
foyers-those type of areas are going to have different
charge limitation requirements than, say, the freezer
that's hidden in the back of the commercial kitchen.
Rodgers: You think of the major difference-especially
these factory-sealed systems-they typically use an A3
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