What Is a Heat Pump?

The simple idea

Most heating systems make heat by burning fuel or running electric coils. A heat pump does something different: it moves existing heat from one place to another. There is heat energy in outdoor air even when it feels cold, and a heat pump can capture it and move it inside. In summer it reverses, moving heat out of your home to cool it.

What it is made of

A heat pump looks a lot like a central air conditioner: an outdoor unit with a compressor, an indoor unit (an air handler or coil), and refrigerant lines connecting them. The key difference is a reversing valve that lets it run in both directions, for heating and cooling.

Why homeowners choose one

One system for the whole year

A heat pump replaces both a furnace and an air conditioner, so you maintain one system instead of two.

Efficiency

Because it moves heat rather than burning fuel, a heat pump can deliver several units of heat for each unit of electricity, which is very efficient in mild and moderate climates.

All-electric

A heat pump needs no gas line, which suits all-electric homes and homeowners moving away from fuel.

Types of heat pump

An air-source heat pump (the most common) exchanges heat with the outdoor air. A ductless mini split is a heat pump that skips the ductwork. In the coldest climates, cold-climate models hold their heat output well below freezing. All work on the same move-the-heat principle.