The increasing use of hydrocarbons (HCs) and flammable HFCs and HFOs has prompted the British Refrigeration Association, BRA, to release the Guide to Flammable Refrigerants which seeks to provide impartial information about the flammability issues associated with hydrocarbons and flammable refrigerants to end users, specifiers, building owners, manufacturers and contractors.

The publication discusses the basic properties of flammable refrigerants such as boiling points and lower flammability limits before going into maximum flammable gas charge sizes.
It provides tables summarizing maximum charge sizes for A2 and A3 class refrigerants according to existing standard EN378 that occur under the most common scenarios. Besides existing refrigerant safety classifications, it briefly also discusses proposed safety classification A2L that is currently proposed in revisions of ISO 817 and EN 378.

The publication provides a good overview of applicable regulations, standards and codes of practice covering the use of flammable refrigerants, including those on the design of systems and components, those specifying the refrigerant charge, specifying how cylinders and charged systems should be transported, as well as those outlining the required competence for engineers.

You can read a summary or download the 23-page guide which is supported by the HEVAC Air Conditioning Group and the Heat Pump Association.

Editors Note: CR4 would like to thank Larry Butz, President and CEO of GEA Consulting, for contributing this blog entry.