Air Conditioner Heat-Cool vs Heat Pump

Some window and wall air conditioners offer heating and cooling.

Heat-Cool Models

During the heat cycle "resistance" heaters are energized and warm air is blown into the room. These are coil heaters similar to electric dryer heaters. You get 3.413 BTUs of heat for every watt expended.

Heat Pump Models

During the heat cycle, the compressor continues to pump and a reversing valve changes the direction of the flow of gas. This process essentially moves the warm condenser coils that are normally outside to the inside. In a warm climate, the heat pump is more efficient, while in a cold climate (average temp below 35 consistently) a heat-cool unit is more efficient.

• At temperatures below 35 degrees, the compressor cycles off for the heat pump and resistance heat is used like a heat-cool unit.
• At 47 degrees, the rating point for heat pumps, it is 2 1/2 times more efficient to operate than a resistance heat unit.
• Split System air conditioner systems (NLA) did not have resistance back-up heat.