What's the Difference Between a Geothermal and Air-Source Heat Pump?

If you’re interested in a cost-effective alternative to your furnace, you’ll probably want to install a heat pump. A heat pump moves heat from a warm source (i.e. from the outdoors) into a colder space (i.e. into your home) – or the other way around if you’re trying to lower the heat. Unlike a traditional heater, a heat pump does not use fossil fuels since it uses the heat that’s already there, making it more eco-friendly. It is also more economical since it combines the capabilities of a furnace and an air conditioner.

What are the two types of heat pumps?

There are two primary types of heat pumps: ground-source heat pumps and air-source heat pumps. We’ll delve into the details below, however, what you need to know is that an air-source heat pump transfers air from the outdoors into the indoors. Meanwhile, a ground-source heat pump gets the heat energy that’s stored in the ground.

How does an air-source heat pump work?

The best way to understand how an air-source heat pump works is by comparing it to a refrigerator. Air-source heat pumps contain a set of coils – one set is installed indoors, while the other is installed outdoors. The coils contain a refrigerant that evaporates as it transfers the heat from the outside air. The refrigerant, now in its gaseous state, makes its way through the coils, and when it enters the home, it turns back into its original state. When this happens, the refrigerant releases heat that a system of fans then pushes into the rest of the house.

How does a ground-source heat pump work?

A ground-source heat pump, also called a geothermal heat pump, captures the heat energy in the ground. Whatever the season, the ground provides a consistent source of heat that’s around 45 to 60 degrees

A geothermal heat pump gets this stored heat via vertical pipes that have been buried deep within the ground. When it captures the heat, it expels it into the house’s indoor unit, where you can find a heat exchanger and air handler. Together, these two components warm the air before pushing it into the ducts, and finally, into the home.

Which is better, an air-source or ground-source heat pump?

The two types of heat pumps are efficient – in fact, the U.S. Department of Energy (DOE) claims that they can reduce heating costs by about 50 percent. Hence, whatever type of heat pump you choose, you can anticipate significant savings.

What you should consider is the initial cost to install them. Ground-source heat pumps are expensive, but considering the long-term savings, you can expect to recover the initial investment in no time. Air-source heat pumps are cheaper, but the reduction in energy costs isn’t as great as ground-source heat pumps

Furthermore, ground-source heat pumps are underground, so you can rest assured that they’re safeguarded from the elements. A well-maintained geothermal heat pump can last around 25 years, while an air-source heat pump can last 15 years.

While a ground-source heat pump seems like the better option, keep in mind that it needs a lot of space. If you’re working with a small area or if you aren’t willing to excavate, you may want to consider an air-source heat pump instead.

Not sure which type of heat pump to install?

Choosing the type of heat pump for your home shouldn’t be done on a whim. Consult an HVAC professional today to find out which type of heat pump is ideal for your property.