Refrigerant

Abstract

A refrigerant that is azeotropic or near-azeotropic comprises a binary blend of R744 and R41. In one embodiment the binary blend has a molar composition of 20 to 60 percent R744, the remainder being R41.

1 . A refrigerant that is azeotropic or near-azeotropic and comprises a binary blend of R170 and R717, wherein the binary blend has a molar composition of 45 percent R170 and 55 percent R717. 
     
     
         2 . A refrigerant according to  claim 1 , wherein the refrigerant has an ozone depletion potential of zero. 
     
     
         3 . A refrigerant according to  claim 1 , wherein the refrigerant has a global warming potential of less than 150. 
     
     
         4 . A refrigerant according to  claim 1 , wherein the refrigerant has a safety classification of A2. 
     
     
         5 . A method of recharging a heat transfer system that includes an existing refrigerant, the method comprising:
 unsealing the heat transfer system to gain access to the existing refrigerant;   removing substantially all of the existing refrigerant from the heat transfer system;   at least partly filling the heat transfer system with a refrigerant that is azeotropic or near-azeotropic and comprises a binary blend of R170 and R717, wherein the binary blend has a molar composition of 45 percent R170 and 55 percent R717; and   resealing the heat transfer system.