Integral water-refrigerant-air heat exchange system

Abstract

A heat transfer system for effecting heating and cooling at maximum system operating cost efficiency in both modes of operation. In a preferred embodiment, a solar collector is utilized to transfer radiant heat from the sun to a heat storage medium, such as water, which is circulated through a water coil of an indoor heat exchanger. A conventional heat pump has an indoor refrigerant coil supported in the same heat exchanger in thermal contact with the water coil. During heating or cooling, air is passed through the heat exchanger and the heat pump is used to supplement the circulating water when the water is insufficient for heating or cooling purposes. The heat exchanger is formed by interpositioning the water carrying coil and the refrigerant carrying coil in thermal contact with each other through the use of common coil fins for the separate fluid carrying conduits. The interpositioning of the fluid carrying conduits using common coil fins permits selective heat tranfer between either or both of the heat exchange fluids and the common coil fins when air is circulated through the heat exchanger, as well as to permit heat transfer between the heat exchange fluids when the fluids are circulated through the coils without air being circulated through the heat exchanger. During lower cost electrical rate periods, such as during off-peak loading, or to take advantage of time-of-day power rates, the heat pump is utilized to transfer heat to or from the heat storage medium for later use during periods of higher electrical energy costs. The exchange of heat between the refrigerant and the storage medium during periods of lower cost electrical energy allows the storage medium to be circulated through the heat exchanger to supplement the heating and cooling operation of the heat pump during time periods when power is more expensive.