Geothermal Heat Pumps vs Air Source Heat Pumps: Which Is Right for You?

Geothermal system mock up of house

If you are trying to decide on the type of heat pump you should get for your house, start to educate yourself on the different kinds of heat pumps. There are many factors to consider when choosing a heat pump like initial cost, efficiency, monthly cost, and comfort.

In this article, we will give you information about two popular types of heat pumps–geothermal and air source. You’ll learn what each one is, how they work, and be able to make a better decision between the two. At Bowman Mechanical Services, Inc., our HVAC professionals have expertise in both geothermal and air source heat pumps and can assist you in making the right decision for your home.

What is a Heat Pump and How Does It Work?

Unlike a traditional fuel-burning furnace, a heat pump simply moves heat from one location to another. Heat pumps are energy-efficient and dramatically reduce harmful emissions. A heat pump can heat your home in the winter and cool it in the summer. How does it do both? Let’s see.

When it is cooling, a heat pump and a refrigerator work similarly. Heat is extracted from the air through a process called the refrigeration cycle. It is a 3-step process that converts liquid refrigerant into a gas and then back into a liquid. There are three main components in the heat pump–the evaporator, compressor, and condenser.

A blower that is connected to the evaporator directs the cooled air into the heat pump’s air distribution. The cycle of refrigeration repeats until your home reaches the temperature setting on the thermostat.

If your heat pump has reverse operation, it can provide heating also. Air source heat pumps extract heat from the outdoor air and condense it until the air is warm enough to heat your home at the appropriate temperature.

Two Types of Heat Pumps

The two primary types of heat pumps are air source (ASHPs) and geothermal (GSHPs), also called “ground source.” The main difference and what sets them apart is where they source their heat from. The GSHP absorbs and transfers heat from the ground and the ASHP transfers heat from the air.

Geothermal Heat Pump

Geothermal heat pumps collect available and renewable heat that is underneath the surface of the earth. This heat has a consistent temperature regardless of the season. No defrost cycle is required and the units maintain a stable output. 

Air Source Heat Pump

The air source heat pump collects air from the outdoors. The temperature of the air is constantly fluctuating so the air source heat pump is adapting to a greater variance of degrees.  Because the above-ground air is inconsistent, an ASHP must work harder in the winter when the air outside is colder and harder in the summer when the air outside is hotter. An ASHP system becomes less efficient as the temperatures vary.

Geothermal Heat Pump Advantages 

Geothermal heat pumps have these advantages over air-source models:

Is more efficient

GSHPs are more efficient than ASHPs because the temperature below ground is relatively stable as compared to the air temperature above ground. The ground temperature at a depth of 10 feet is probably going to remain around 50 degrees Fahrenheit all winter. This causes the GSHP to operate at peak efficiency more of the time. 

Has longer lifespan and little maintenance

The heat loops for a geothermal heat pump can last over 50 years. This is a long-time investment that has a great return over time. Very little maintenance is required over the lifetime of the system. Only the heat pump itself needs to be replaced at some point, probably after 20 to 25 years.

Saves money over time

As compared to costs of conventional air conditioners, furnaces, and ASHPs in maintenance and replacement, a geothermal system’s initial cost becomes worth it. A GSHP has extremely low operating costs as compared to an ASHP’s cost. You can expect to invest about $12,000 to $30,000 for a complete geothermal installation. For large homes, the cost can range from $30,000 to $45,000 for high-end ground source heat pump systems. The size of the home, the location, types of soil, available land, and local climate all influence the GSHP costs you invest initially.

Adds to your home’s equity

Installing geothermal heating and cooling is a huge improvement that increases your home’s value. A GSHP is a limitless heating and cooling source in the yard, instead of one that costs money every time you adjust your thermostat.

Air Source Heat Pump Advantages

Air source heat pumps have these advantages over geothermal heat pumps:

Cost less up-front

The up-front costs for air-source heat pumps are much lower than for geothermal systems. An ASHP on average costs between $3,625 and $5,200 for each indoor air handler unit you install in each room (or zone). The cost of a total installation of a ducted central ASHP can cost between $10,500 and $18,975. It depends on how many indoor units, the home size, and if you need ductwork replacement or installation. 

Better return on investment in moderate climates

If you live in a geographic area that has a moderate climate, your ASHP will have a better return on investment. If you live in an area that has colder temperatures, you may see a decreased return.

Contact Us Today For Help!

As you can see, there is a lot for you to consider when deciding between a geothermal heat pump and an air source heat pump system. You have to think about long-term, cost savings over time, your climate, and many other factors. At Bowman Mechanical Services, Inc. we can help you through the decision-making process and show you different types of heat pumps. Call us at 919-679-9756 or contact us on the form below.