PROGRAMMABLE ELECTRONIC THERMOSTAT WITH MEANS FOR ENABLING ECONOMICALRECOVERY

摘要

ABSTRACT OF THE DISCLOSUREA programmable electronic thermostat is provided for controllingoperation of a multistage heating apparatus comprising a heat pump and auxiliaryheat. A salient feature is a program which provides for economical recovery from asetback temperature. The program includes logic which determines, at thebeginning of the recovery time, whether any or all of the auxiliary stages will betemporarily locked out and thus prevented from being energized. Thisdetermination is based on a characteristic which is dependent upon the heatingdemand that is presently being placed on the heating apparatus. The program alsoincludes logic which determines, near the end of the recovery time, whether any or111 of the locked stages are to be unlocked. This determination is based on themagnitude of the difference between the temperature existing at the time ofdetermination and the temperature desired at the end of the recovery time.