Risk analysis of flammable refrigerants. 1. Correlations for concentrations from leaks.

The use of hydrocarbon refrigerants can result in the occurrence of flammable concentrations in the event of a leak from a system. Both the characteristics of a release and the conditions under which the release occur can affect how the concentrations develop within the immediate environment. Whilst the authors have previously published correlations for estimating the spatial and temporal variations of refrigerant concentrations under various conditions and leak scenarios, the availability of new data has allowed the development of some new correlations with improved accuracy and applicability. In addition, examples are provided as to how the correlations can be employed to assist design of equipment that employs flammable refrigerant. See also this Bulletin, references 2009-0526 and 0527.