This Is How Your Heat Pump Works (2024)

The basic principle of physics that explains heat pump technology has been in use for centuries. The ancient Chinese used the geothermal power of natural hot springs to heat their homes. However, despite its long history, heat pumps are still a bit difficult to understand, and here’s why: A heat pump is not a furnace, but it can warm your home. And it’s not an air conditioner, but it can cool your home. Say, what?

Simply stated, a heat pump is an all-in-one heating and cooling appliance that’s engineered to keep your home comfortable all year round. It consists of two main components: An indoor air handler and an outdoor heat pump, which is similar to a central air-conditioning unit. The pump has a compressor that absorbs and then releases heat. In summer, the heat pump operates much like an air conditioner, absorbing heat from inside your home and expelling it outdoors. In winter, the process reverses and the pump extracts heat from outside air and delivers it indoors to heat your home. And heat pumps are adaptable; they can absorb heat from three different sources: the air, ground or water.

The air-source method is by far the most common—and affordable—way to operate a heat pump. And because it uses electricity to transfer heat, rather than burning fuel, a heat pump is much more energy efficient than most other heating appliances, typically using 50 percent less energy.

Perhaps the most amazing thing about a heat pump is that it can extract heat from cold air because even cold air contains some heat. For example, imagine standing outside in 30º F weather. You’d feel cold, right? But, you’d be warmer than if the temperature dropped to 10º. It’s that ability to absorb heat from air—even cold air—that makes heat pumps reliable and much more energy efficient than single-source systems that only produce either cool or warm air.

And that brings us to another great thing about a heat pump: it doesn’t generate heat from scratch. Instead, it simply moves or “pumps” heat from one place to another, and the result is a significant reduction in energy consumption.

So Why Doesn't Every Home Have a Heat Pump?

Now you might be wondering why doesn’t every home have a heat pump, and here’s the reason: Heat pumps are ideal for regions with moderate climates, but are less efficient in areas with long, frigid winters. As a general rule, heat pumps are effective at temperatures around 30º F or so. Any colder than that and the pump will struggle to extract heat, causing it to run much less efficiently.

However, that doesn’t mean a heat pump isn’t a viable option, regardless of where you live. In cold-weather regions that require a lot of home heating, the heat pump can be coupled with a gas furnace, something known as a dual-fuel system. When the weather turns cool, the heat pump produces heat and uses the furnace to blow warm air throughout the house. In very cold weather, when the heat pump can’t extract the necessary BTUs, it automatically shuts down and the furnace kicks on.

And in predominantly hot-weather regions, where heating isn’t as important, the heat pump can be paired with an air handler. In this arrangement, the heat pump heats or cools the air and the air handler circulates it throughout the house. To find out if a heat pump is a viable alternative for your home, contact a licensed heating-and-cooling contractor.