R290 Charge Limit – Progress & Next Steps

Amidst increasing regulatory pressures at the state and federal levels, a growing number of US food retailers are looking to natural refrigerants – including carbon dioxide, ammonia, and propane – as future-proof options. Propane solutions offer opportunities for new and existing stores, but innovation has been limited due to the current allowable charge size of 150g per circuit in self-contained cases. Much of the industry is anxiously awaiting the approval of higher charge sizes for propane through codes and standards due to potential energy, capacity, and cost benefits.

2019 marked a turning point when 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. After the publication of the updated IEC standard, a CANENA technical harmonization committee led a harmonization effort that resulted in an updated UL-60335-2-89 (UL 2-89) standard allowing up to 300g per circuit in cases with doors and 500g per circuit in open cases. The updated standard has been finalized and was published last Wednesday, October 27th.

But as new regulations begin to take effect in the US, there is a need to accelerate the approval of the higher charge sizes through other codes and standards updates. We’ve put together a brief summary of the status and next steps for each of the remaining updates needed for the widespread approval of higher propane charge limits in the US:

ASHRAE 15

• Status: In Progress

• Summary: The ASHRAE 15 committee has drafted an addendum to approve the higher charge sizes in alignment with UL 2-89 for listed equipment. The addendum is expected to be released for a public comment period in the near future.

• Next Steps: NASRC will continue to monitor the standard update.

EPA SNAP

• Status: In Progress

• Summary: Multiple applications have been submitted to the EPA to approve the higher charge sizes in alignment with UL 2-89. The EPA has been unable to process those applications without a published standard that incorporates the higher charge sizes. Now that the updated UL 2-89 standard has been published, the EPA can begin to process applications to approve the higher charge sizes.

• Next Steps: NASRC will push for accelerated approval of higher charge sizes.

Building Codes

• Status: In Progress

• Summary: Building codes are typically updated in accordance with international building code updates. Currently, the international building codes do not align with the higher charge sizes listed in UL 2-89, but there will be an opportunity to update the international codes to reflect the new UL 2-89 in early 2022. Once the international codes have been updated, a state-by-state effort to update building codes will be necessary. This will be the biggest and most time-consuming challenge to get the higher charge sizes approved.

• Next Steps: NASRC will collaborate with AHRI and a coalition of other NGOs to ensure the international codes are updated and accelerate building code updates at the state level. Contact us to get involved.