ASHRAE Seeking Public Comments on Proposal to Boost Charge Limit for A3, A2L Refrigerants

ASHRAE is seeking comments from the public on a proposal to expand the allowable charge sizes for A3 (flammable) and A2L (less flammable) refrigerants in commercial refrigeration equipment used in North America.

The 30-day advisory public review (APR) period for the proposal, which began on April 9, ends on May 9.

Text of the proposal – which would modify the ASHRAE 15 Safety Standard for Refrigeration Systems – can be found here. Anyone can comment by signing in – or signing up – here. 

“It’s important for the industry to share comments supporting A3 refrigerants," said Christina Starr, Senior Policy Analyst, Climate Campaign, for the Environmental Investigation Agency (EIA).

The ASHRAE-15 proposal includes a recent addition whereby both A2L and A3 stand-alone equipment with larger charges have to include a label forbidding installation within 20ft (6.1m) of an open flame. 

Following the public comment period, and consideration of comments, the 20-member ASHRAE-15 committee would vote on the APR proposal.  If approved, it would move to the more rigorous Publication Public Review (PPR) process that would precede any final adoption.

The APR proposal for both A2L and A3 refrigerants received the most votes (10) when the ASHRAE 15 committee voted on January 14 to approve one of three motions on higher charge limits for flammable refrigerants in commercial display cases. The other two motions were for a PPR proposal for higher charge limits for A3 and A2L refrigerants, and a PPR proposal for higher charge limits for A2L refrigerants only.

Based on proposed UL standard

ASHRAE-15’s higher charge limit proposal for A3 and A2L refrigerants follows proposed revisions to UL 60335-2-89, a separate standard for commercial refrigerating appliances, released last year by Underwriters Laboratories (UL) for the U.S. market. The proposed update has been managed by CANENA (a standards harmonization body for the Americas) Working Group 12, in collaboration with UL and CSA (Canadian Standards Association). Revisions to UL 6033—2-89 are expected to be finalized by July.

The UL proposal is based on, though different from, the latest version of the International Electrotechnical Commission (IEC) 60335-2-89 standard, approved in 2019.

The proposed UL standard calls for raising the charge limit for A3 refrigerants in factory-sealed, self-contained commercial appliances, under certain conditions, to 13 times the LFL, but only for open appliances (without doors); it proposes raising the charge limit for closed appliances with doors and/or drawers to eight times the LFL This would increase the charge limit for propane (R290) from 150g to 500g or 300g, respectively.

Under the proposed UL standard, field-erected systems consisting of various partial units employing an A2L refrigerant would fall under three charge-limit categories: m1 (13 times LFL, except for ice makers and products with doors or drawers, for which the limit is eight times LFL; m2 (52 times LFL); and m3 (260 times LFL).