ASHRAE 15-2024 (packaged w/Standard 34-2024) ✓ Most Recent

ASHRAE Standard 15 specifies requirements for the safe design, construction, installation, and operation of refrigeration systems. The 2024 edition addresses several aspects of flammable refrigerant use, clarifies requirements related to pressure relief devices as well as specific requirements that have precedence over general requirements, updates values of conversion factors for use in the calculation of effective dispersal volume charge (EDVC), and modifies requirements for handling, transportation, and storage of flammable refrigerants.

ASHRAE Standard 34 describes a shorthand way of naming refrigerants, and it assigns safety classifications and refrigerant concentration limits based on toxicity and flammability data. The 2024 edition adds 28 refrigerants as well as burning velocity data for flammable refrigerants, expands refrigerant numbering descriptions of the ethane series to incorporate the ethene series, adds ethers and cyclobutene to the list of substances that can be explicitly determined from the refrigerant numbers, and clarifies the allowable pressure range for flammability testing. It also includes revisions to allow further alignment with ISO Standard 817, including updating the definition of occupational exposure limit (OEL), clarifying toxicity data, and revising application requirements.

The new editions of Standards 15 and 34 have been published in 2024 to better align with the timing of building code updates.