... energy. COP:4-4.5 heat pump solar water heater with free solar energy solar water heater with heat pumpI. Feature:1. Energy saving;2 ... winter days; II. Working Principles;In the sunny days, the solar water heater can heat the cold water into 40-50 ... , this air gets into the condenser to exchange the heat with water, then the condensed air become low temperature fluid and ...