AHRI Releases Refrigerant Research Results

March 16, 2021
In a study that's a critical step to modifying building codes, A2L -- mildly flammable -- refrigerants were found to be difficult to ignite, and had low flame speeds.

The process of modifying building codes to accommodate the use of "mildly flammable" refrigerants took a significant step forward today, with the release by The Air-Conditioning, Heating, and Refrigeration Institute (AHRI) of research results from a study of those refrigerants undertaken in cooperation with UL and the Firefighter Safety Research Institute (FSRI). In this study, refrigerants classified by the American Society of Heating, Refrigerating, and Air Conditioning Engineers (ASHRAE) as A2L (lower  flammability) were tested and compared with A1 (no flame-spread) refrigerants in real-world situations. The effort was undertaken to develop training programs for firefighting personnel when responding to fires in occupancies with both new (A2L) and existing (A1) refrigerants.

Among the study's most important findings is that A2L refrigerants were found to be difficult to ignite, and had low flame spread. See THIS LINK.

 The project included scenarios designed by fire service professionals to develop training for tactical consideration to demonstrate hazards that may be encountered by the fire service for both A1 and A2L refrigerants.

Those scenarios were:

  • Scenario 1: Comparison and contribution of A1 and A2L refrigerants relative to heat and gases generated in an open flame.: 
  • Scenario 2: Hazards during suppression activity from change in fire dynamics in the hallway where firefighters may be advancing towards the fire room with a forced refrigerant release in ventilationcontrolled conditions.
  • Scenario 3: This scenario was planned as optional pending a review of Scenario 2. The difference between Scenario 2 and Scenario 3 is that the leak would not be forced as in Scenario 2.
  • Scenario 4: Hazards in fire room during overhaul activity if firefighters action results in a refrigerant line break.
  • Scenario 5: Fire conditions in a below grade closed room without any air movement, having an excessive amount of refrigerant pooling, well above the allowable limits of refrigerant to demonstrate how refrigerant burns when ignited with a flame     

“We are grateful to the UL employees and members of the fire service that committed significant time in the development and execution of this project and in preparing reports to ensure that they are both accurate and helpful to firefighters,” stated Helen Walter-Terrinoni, AHRI Vice President of Regulatory Affairs.

Since industry started pursuing a phasedown of higher-global warming potential (GWP) refrigerants over 10 years ago, more than $7 million has been invested in research to better understand the lower-GWP refrigerants that will replace them.

The FSRI training module, which incorporates videos from the project, will soon be released and available free-of-charge on its website, ulfirefightersafety.org.