ASHRAE Publishes Refrigerant Safety Standards - ANSI/ASHRAE 34, ANSI/ASHRAE 15

July 16, 2007 // Published as a news service by IHS

The organization also issued ANSI/ASHRAE 15-2007 - Safety Standard for Refrigeration Systems to establish procedures for operating equipment and systems to assure the safety of building occupants and system technicians.

ANSI/ASHRAE 34-2007 - Designation and Safety Classification of Refrigerants
According to ASHRAE, ANSI/ASHRAE 34-2007 was designed to establish a means of referring to common refrigerants in place of chemical names, formulas or trade names. It also establishes safety classifications based on toxicity and flammability data.

The updated 2007 version contains 16 new refrigerants.

ANSI/ASHRAE 34-2007 includes revisions to the flammability classification and details on the flammability and fractionation testing procedures.

The updates were designed to make it easier for manufacturers to prepare applications for refrigerant number assignment and safety classification, according to Bill Walter, Standard 34 committee chair.

A new section also was added specifying the criteria to determine recommended refrigerant concentration limits (RCL) in occupied spaces. The addition of RCL values is said to be useful in application of the refrigerants in the field.

"In general, incorporating the 23 approved addenda into one document makes the standard easier to read and understand … the current requirements to get a refrigerant listed in the standard," Walter said of ANSI/ASHRAE 34-2007.

ANSI/ASHRAE 15-2007 - Safety Standard for Refrigeration Systems
One significant change featured in ANSI/ASHRAE 15-2007 when compared to the 2004 version is expanded requirements for safety relief protection piped internally to systems.

"In the interest of keeping refrigerants contained within a refrigeration system, a growing number of designers sought to implement pressure relief protection that discharged overpressure refrigerants to a lower pressure portion of the system," said Douglas Reindl, committee chair.

"This change is intended to guard safety in these applications by expanding requirements for the engineering of internal relief devices," he said.

The update to Appendix F, which outlines the principles of relief device selection for positive displacement compressors, included the expansion of the list of refrigerants with corresponding properties.

ANSI/ASHRAE 15 was first published in 1919 as Tentative Code for the Regulation of Refrigerating Machines and Refrigerants in recognition of the need for cities and states to enact safety regulations.

Source: American Society of Heating, Refrigerating and Air-Conditioning Engineers Inc. (ASHRAE).