Patent ID: 7963117

Claim:
A variable-speed HVAC system for a mobile unit having an engine, the variable-speed HVAC system comprising: a variable-speed compressor; a variable-speed evaporator fan; a controller for controlling the operation of the variable-speed HVAC system; a first DC-power source having a DC battery to start the mobile unit's engine; a second DC-power source having a DC battery connected to the first DC-power source; a speed-control circuit having a plurality of speed-control sub circuits; a condenser having a discharge line; a variable-speed condenser fan; and a temperature sensor connected to the variable-speed condenser fan; wherein the second DC-power source provides DC power to the variable-speed compressor and the variable-speed evaporator fan when the mobile unit's engine is not operating, wherein each speed-control sub circuit limits each speed of the variable-speed compressor to a specific speed of the variable-speed evaporator fan, wherein the temperature sensor measures a temperature of the condenser discharge line, and wherein if the measured temperature of the condenser discharge line is below a predetermined temperature then the variable-speed condenser fan will operate at a first speed and if the temperature of the condenser discharge line is above the predetermined temperature, then the variable-speed condenser fan will operate at a second speed that is lower than the first speed.