Hydrocarbon refrigerant charge limits for quiescent rooms
Abstract Concentration measurements and analysis have been used to develop new methodology for estimating the allowable charge limit (ACL) of flammable refrigerants, particularly R290. Attention has been given to the impacts of construction and dimensional characteristics of the RACHP enclosures, in particular the size and position of the openings, on the concentrations exiting the enclosure. Analysis of the data has shown that these are critical aspects that influence floor concentration and/or safe allowable refrigerant charge limits. Formulae have been proposed to estimate layer-volume heights and ultimately ACL. The results illustrate that current standard's ACLs are overly restrictive, especially for certain types of RACHP equipment.