Installing a geothermal heat pump
Last updated 8/7/2019
The installation process for ground source heat pumps (GSHPs) on your property will depend on the type of ground loop you’re installing and whether you require a new duct system, among other factors.
Before installation: learn your heating and cooling needs
Before you install ground source heat pumps, your home contractor will visit your property to assess your heating and cooling needs. They may perform a “Manual J” calculation, which provides information about heating and cooling loads for your property. A Manual J is often required to be eligible for any state and local incentives. Your contractor will also likely inspect any pre-existing ductwork to make sure it’s efficient and well-sealed.
During the visit, home contractors will also ask questions about your existing climate control system, as well as about your goals for the project. For example, are you looking to only heat a new addition to your home, or do you want to cover as much of your property as possible with the new system? Your answers to these questions will affect the type and size of geothermal system they propose.
Ground source heat pump installations in four main steps
There are four main steps to a ground source heat pump installation:
- Ground loop installation
- Ductwork installation
- Heat pump installation
- Wiring and final connections
The first three steps won’t necessarily be completed in the order shown, as the ground loop, ductwork, and heat pump are all physically separate components. Additionally, ductwork only needs to be installed if your property has none, or if your pre-existing ducts need heavy repairs. A geothermal heat pump system can be installed as a retrofit (as opposed to during new construction), so if you have an existing and working duct system, there’s no need to replace it.
1. Ground loop installation
The first step in a geothermal heat pump installation is to install the ground loop. Your contractor will need to bring heavy machinery onto your property to dig the trench, and will follow up by installing the actual piping in the ground. For horizontal ground loops, your installer will need to dig trenches about 6 feet deep and 3 feet wide. For a vertical ground loop, your installer will potentially need to drill several hundred feet deep into the earth.
2. Ductwork installation (if necessary)
After digging the necessary trenches and installing the ground loop equipment, your geothermal installer will install any necessary indoor ductwork. This step is optional: if you have adequate pre-existing ducts, you can simply use that system to transport heated or cooled air.
3. Heat pump installation
Next comes the installation of the heat pump unit itself. If you are replacing an existing furnace and central air conditioning unit, your installer will need to remove those components first. The new heat pump will be set in place and connected to your duct system.
4. Wiring and final connections
Finally, your heat pump will be connected to the ground loop to allow heat to flow, as well as to your home electrical system to make sure the fan has power to run and blow air throughout your home.