Abstract: A method and apparatus for integrating operation of a heat pump and a separate heating source are disclosed. The combination of a heating lockout relay and an interlock relay are utilized to provide for fail safe integrated operation including providing for selected control functions and for isolating other functions to prevent a failed electrical component from operating the system in an undesirable manner.

Abstract: Air conditioning apparatus and a method of operation thereof, said apparatus being mounted such that the indoor section receives air to be conditioned through an opening in the bottom wall of the unit and likewise discharges the conditioned air into the enclosure to be treated through an opening in the bottom wall of the unit. The heat exchanger, fan and supplementary heaters, if used, are arranged to maximize air flow per given fan power input such that the overall efficiency of the unit can be increased by decreasing the necessary energy to circulate air through the unit. An internal wall is used to support the fan as well as define air flow paths.