Water heating system

Abstract

A water heating system comprising an outdoor heat exchanger including a heat collection chamber, solar collector panels, collector fins, an evaporator for passing refrigerant therethrough to perform the heat exchange between the refrigerant and the heat transferred from the panels and fins to evaporate the refrigerant. The panels, fins and evaporator are incorporated integrally in the heat collection chamber. A variable rotational speed compressor is connected to the outdoor heat exchanger for compressing the vaporized refrigerant from the evaporator. A heat exchanger disposed on the bottom side in the water storage tank passes the refrigerant vapor from the compressor to perform the heat exchange between the water in the tank and the refrigerant vapor to condense the refrigerant vapor. A variable opening expansion valve adiabatically expands the refrigerant liquefied by the heat exchanger in the tank, thereby decreasing the pressure and temperature of the refrigerant and supplies the refrigerant thus adiabatically expanded to the outdoor heat exchanger. A control unit controls the rotational speed of the compressor and the opening of the expansion valve to maximize the coefficients of performance of the refrigeration cycle in response to the pressures and temperatures measured at various portions in the refrigeration cycle.