Last year, the International Electrotechnical Commission (IEC) 60336-2-89 standard was updated to increase the charge limit for A3 refrigerants - including R-290 (Propane) and R-600a (Isobutane) - to 500g at the international level. Since then, a CANENA technical harmonization committee has been working to adapt the IEC standard in the US, where the charge limit is still 150g.
NASRC recently co-hosted a member Q&A session on the pending charge limit increase in the US with Charlie Hon, who currently serves as the chairman for the CANENA committee. Here’s a few updates on the status and next steps to increase the R290 charge limit in the US:
CANENA - The CANENA committee has drafted an update to the UL 60335-2-89 standard, which would increase the charge limit for A3 refrigerants to 300g for self-contained systems with doors or drawers and 500g for other self-contained systems (e.g., open cases) in the US.
UL - The draft update has been submitted to UL, and in the next few months it will be sent out for a public comment period and the UL committee will vote to approve it. The standard is expected to be approved by Q1 2021.
In addition to the UL standard update, the following steps must be completed before the larger A3 charge sizes are allowable:
EPA SNAP - EPA SNAP must accept the larger charge sizes before they can be sold. The CANENA committee will submit an application to EPA SNAP as soon as the updated UL standard is approved.
ASHRAE 15 - The ASHRAE 15 standard must be revised to include the larger charge sizes. This effort is being done in coordination with the CANENA committee.
Building Codes - National Building and Fire Codes will need to be modified. The next code cycle takes place in 2022.
All of these steps are expected to be completed by 2022 at the earliest, at which point the higher A3 charge sizes would be approved for use.
So what does all of this mean? Basically, a future with higher R290 charge sizes in self-contained equipment is on the horizon, but there is still work to be done.