Air source and ground source heat pumps

Posted by Guest Blogger on April 17, 2012

Imagine using a single, very efficient unit to both heat and cool your home. Heat pumps not only make this possible, but can potentially greatly reduce your heating and cooling costs.

A heat pump is a system that heats your home during the winter and reverses that operation to cool your home during the summer. Heat pumps do not create heat like combustion furnaces, but simply use fluids and compressors to transfer heat from where it is to where you want it to go.

There are two types of heat pumps: air source and ground source. An air-source system gets its heat from the air, while a ground-source system gets its heat from the ground. Although both of these systems operate on the same principle, they have some distinct differences.

An air-source heat pump is less expensive to install than a ground-source system. Because air-source systems draw heat directly from the air, their installation process involves less equipment, as well as less labor. However, ground-source heat pumps utilize pipes embedded several feet underground, which require extra materials and extensive labor. Trenches must be dug, pipe laid and at least some landscaping redone when ground-source heat pumps are installed.

So why would someone choose to install a ground-source heat pump instead of an air source heat pump? After the initial expense of the installation, ground-source heat pumps are more efficient than air source.

Because the system lies underground where temperatures tend to remain constant, there are fewer fluctuations in the compressor loads allowing the heat pump to work with less effort. Ground-source systems can also cut some hot water heating costs by using a device called a desuperheater.

Air source heat pumps are still an excellent choice for mild climates. These devices can help reduce electric use by as much as 40 percent and can deliver as much as three times more heat energy than what they consume.

As an additional benefit to installing a heat pump, Wright Hennepin has Off-Peak rates for both air source and ground source heat pumps, and rebates to help with the cost of initially installing these units.