The primary difference between air source heat pumps (ASHPs) and a geothermal heat pump (GHP) is that the ASHP moves heat to and from the air while a GHP uses the ground to find or deposit heat.
How They Work
A heat pump can both heat and cool a home. In the winter, it extracts heat from the outdoors and moves it inside. The reversing valve in the system changes the flow of heat from winter to summer. When you need cooling, the pump will move the heat indoors to the outdoors via the refrigerant.
A GHP is more energy efficient than an ASHP because the temperatures below ground are stable, unlike air temperatures that have wide swings. It’s much easier to find heat underground in temperatures around 50 degrees F than it is to extract it from air that’s 32 degrees or lower.
Geothermal heat pumps last longer than an air source heat pump. Instead of using an above-ground condenser that the ASHP does, the GHP uses an underground loop field that experiences no weather. Most manufacturers provide a 50-year warranty for the loop field for a GHP. An ASHP has a life expectancy from 10 to 15 years.
A GHP costs significantly more than an ASHP, but it pays you back each time it runs in much lower energy bills, reduced maintenance, and a longer lifetime. If you install a qualifying GHP before January 1, 2020, you can claim a 26 percent federal tax credit for the cost of the equipment and its installation.
In years past, lot size determined whether a GHP would work. However, with new ways to place the coils, all but the smallest yard is suitable for a GHP. The loops can be installed vertically instead of horizontally when outdoor space is at a premium. A GHP isn’t suitable as an independent HVAC system in the condo buildings due to land constraints.
If you’d like to learn more about heat pumps, contact Hartman Bros. Heating & Air Conditioning, providing HVAC services for New Haven homeowners.
Our goal is to help educate our customers in New Haven, Indiana and surrounding Fort Wayne area about energy and home comfort issues (specific to HVAC systems). For more information about other HVAC topics, download our free Home Comfort Guide or call us at 260-376-2961.