Abstract: A temperature control system for a multiplant environmental unit utilizing a heat pump and auxiliary heat is specifically disclosed. This system is operated by a microcomputer based real time operated thermostat which provides night setback and day setup in an energy efficient manner. The efficient operation is accomplished by having separate heat pump and auxiliary heat ramp rates that can be operated together in parallel in a first mode of operation, and operated separately in a second mode of operation.

Abstract: A temperature control system for a multiplant environmental unit such as a heat pump with auxiliary heat is disclosed. The control system utilizes a thermostat having a microprocessor and memory that allows for energy savings through setback functions. The setback functions return the temperature control from a setback temperature to a normal comfort temperature along a ramped rate that is modified from day to day. The purpose of this variable ramp is to minimize the operation of the auxliary heat and maximize shell savings (by starting as late as possible). This is basically accomplished by locking the heat pump on in certain cases.