Abstract: An apparatus and method for controlling the sequential operation of supplemental electric heaters so that the amount of energy consumption is minimized. The operation of the heaters is prevented as long as a lower night set-back temperature can reach the higher reference set point during the daytime within a predetermined time interval. A microprocessor is provided to control the operation of night set-back automatically to affect a measured temperature of the conditioned space.

Abstract: An apparatus and method for controlling continuously and discretely the speed of an indoor evaporator fan motor and the speed of the compressor as a function of the fan speed for regulating the dry bulb temperature and relative humidity of a conditioned space includes a programmed control device which produces a first signal for driving a fan inverter connected to the evaporator fan motor. A second signal, which is a function of the first signal, is also provided by the control device to drive a compressor inverter coupled to the compressor. A microprocessor having a program is operatively connected to the programmed control device for controlling its operation to effect the measured temperature of the conditioned space.