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 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 state and local incentives. Your contractor will inspect any pre-existing ductwork to ensure it’s efficient and well-sealed.
During the visit, home contractors will also ask questions about your existing climate control system and 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 the geothermal system they propose.
There are four main steps to a ground source heat pump installation:
Ground loop 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 must only be installed if your property has none or 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
Installing the ground loop is the first step in a geothermal heat pump installation. 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 must dig trenches about 6 feet deep and 3 feet wide. For a vertical ground loop, your installer might need to drill several hundred feet deep into the earth.
2. Ductwork installation (if necessary)
After digging the required trenches and installing the ground loop equipment, your geothermal installer will install any essential indoor ductwork. This step is optional: if you have adequate pre-existing ducts, you can use that system to transport heated or cooled air.
3. Heat pump installation
Next comes the structure of the heat pump unit itself. If replacing an existing furnace and central air conditioning unit, your installer must remove those components first. The new heat pump will be installed 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 and to your home electrical system to ensure the fan has the power to run and blow air throughout your home.