In this study, a mathematical model of a solar-assisted heat pump system with latent heat energy storage for residential heating in Turkey was developed. The model consists of dynamic and heat transfer relations concerning the fundamental equipment in the system such as solar collector, latent thermal energy storage tank, compressor, condenser, evaporator and building heating load. Some model parameters of the system were calculated by using experimental results. It was found that the model agreed well with the experimental results. Copyright (C) 1999 John Wiley & Sons, Ltd.