Heat Pump

How one machine heats and cools

A heat pump contains the same parts as a central air conditioner — compressor, two coils, refrigerant — plus a reversing valve that flips the direction of refrigerant flow. In cooling mode, the indoor coil absorbs heat and the outdoor coil rejects it. In heating mode, the roles swap: the outdoor coil pulls heat out of winter air (there is usable heat in air well below freezing) and the indoor coil releases it into the house. Because the system transfers heat instead of creating it by combustion or resistance, it commonly delivers two to three units of heat per unit of electricity in moderate weather.

As outdoor temperatures fall, a heat pump's capacity drops just as the home needs more heat. Standard systems rely on backup heat — electric heat strips or a furnace in a dual-fuel setup — during cold snaps, while modern cold-climate models maintain strong output well below freezing.

Are heat pumps a fit for Southeastern Pennsylvania?

The Philadelphia region's winters are cold but rarely extreme, which puts it squarely in heat pump territory, especially with today's cold-climate equipment. Heat pumps are a natural choice when an aging AC and furnace need replacement at the same time, when a home has no gas service, or when owners want to move off oil. Efficiency is rated by SEER2 for cooling and HSPF2 for heating, and proper sizing through a load calculation matters even more than with a furnace. PJ MAC HVAC repairs and installs heat pumps alongside gas and oil systems, so the comparison can be made for your actual house rather than in the abstract.