AbstractA thermodynamic analysis of the vapour absorption heat pump (VAHP) cycle is made to study the performance of four fluorocarbon based working fluid pairs namely, R21‐DMETEG, R21‐DMF, R22‐DMETEG and R22‐DMF. The performance characteristics compared are total heat output per unit solution flow rate; heating coefficient of performance; second law efficiency and circulation ratio. Among the four combinations, R21‐DMETEG stands out as the most suitable solution for low temperature VAHP applications. Correlations are given for quick estimation of COP and limiting generator temperature. The effects of mass transfer effectiveness at generator and absorber on the performance are also inv