Flammable Refrigerants Charge Limits to be Raised?

By Danny Halel posted 01-23-2018 10:32 AM


I recently attended the North American Sustainable Refrigeration Council (NASRC) Stakeholder Workshop in Washington, D.C., along with OEM’s, other industry associations, EPA, contractors and end users. For self-contained refrigeration equipment (as used in convenience stores and supermarkets), their goal was to set in motion the wheels, to raise the current ASHRAE designated A3 refrigerants charge limit from 150 grams (~5.3 ounces) to some higher level; say, 500 g (~1.1 lbs.).

ASHRAE designated A3 refrigerants (propane is a prime example) have been around for decades.  However, they have always had a stumbling block in that they are flammable.  

The NASRC made their “pitch” for the use of flammable refrigerants in these small, self-contained units stating that maintenance needs for this equipment type are very low, and, for all intents, the equipment does not leak refrigerant.

I created a pros and cons charge for flammable refrigerants:

Increasing the A3 charge limit from 150 grams to 500 grams



Installation costs down by 20% to 30%.

Low per lb. refrigerant cost.

Capital costs are 30% to 40% higher.

Air Cooled units can be utilized, however, size is limited.

Air Cooled units adds to the building cooling load.

Over 1,000,000 A3 units installed worldwide with very few failures.

Lack of certified technicians and installers.

No redundancy if a failure occurs.

Risk of thermal event is low – but not zero.

Doors can be removed on some systems.

Consumer may still need to open door to obtain product.

Lower energy costs by 15% to 30%.

Maintenance if required is generally performed off-site.

Lower Total Cost of Ownership = Capital + Installation + Maintenance + Energy + Decommissioning

Depending on the design of the unit, an A3 refrigerant’s lower flammability limit (LFL) could be reached under certain conditions.


The following standards would need to be revised to allow for an increase of charge limits from today’s current 150 gram requirement:

  • ANSI/ASHRAE 15 – Safety Standard for Refrigeration Systems
  • ANSI/UL 60335-2-24 Safety Requirements for Household and Similar Electrical Appliances, Part 2: Particular Requirements for Refrigerating Appliances, Ice-Cream Appliances and Ice-Makers
  • ANSI/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
  • U.S.E.P.A. Significant New Alternatives Policy (SNAP) Regulations

 After much discussion, and the review of the steps to be taken to propose changes to the above standards, the NASRC will be proposing raising the limits in ASHRAE 15, UL 60335-2-89, and EPA SNAP to 500 grams. If approved, OEM’s will be able to make larger self-contained merchandisers.

There was one significant caveat. Today there are very few entities that certify installers and technicians on the proper installation, maintenance and, de-commissioning of these units.

The NASRC has a taskforce developed to ensure that this issue is being addressed, ACCA is a part of this taskforce and will protect the contracting industry’s interests.

The issue of certified installers and technicians must be addressed before the change can be made. ACCA supports efforts to safely transition to new products, insisting that all safety concerns are addressed first.