Honeywell International Inc.
HEAT TRANSFER COMPOSITIONS AND METHODS

Abstract:

Disclosed are methods of retrofitting heat transfer systems containing or designed to containing HFC-134a as the refrigerant comprising: removing at least a portion of said HFC-134a from said system; and introducing into said system a refrigerant comprising at least about 97.5% by weight of the following four components, with each compound being present in the following relative percentages: (a) from 2% to about 7% by weight of difluoromethane (HFC-32); (b) from 2% to about 7 by weight of pentafluoroethane (HFC-125); (c) from about 35% to about 50% by weight of 1,1,1,2-tetrafluoroethane (HFC-134a); and (d) from about 50% to about 55% by weight of trans-1,3,3,3-tetrafluoropropene (HFO-1234ze(E)).