ASHRAE Standard 35-76 presents a method of testing refrigerant drying desiccants. An alternate method of testing, that addresses the requirements of ASHRAE Standard 35-76, is presented and discussed. A detailed error analysis for both ASHRAE Standard 35-76 and the present method, which is based on the use of both a Karl Fischer titration and an electronic hygrometer for de­termination of the water content of the liquid phase refrigerant, is presented. Finally, water in liquid phase refrigerant isotherms are presented for several commercial refrigerant desiccants and they are compared to isotherms for similar products obtained by methods largely in accordance with ASHRAE Standard 35-76.