Using ground source heat pumps for year-round comfort

November 5, 2015
Ground source heat pumps (GSHPs) are a low-energy, low-maintenance way to heat and cool your home. By drawing from the ground temperature, GSHPs provide an energy-efficient way for transferring heat to or from the home. Also called geothermal heat pumps, GSHPs are helping homeowners keep their home comfortable throughout the year. At CaliforniaFIRST, we'll help you afford the installation cost of a GSHP.

How do ground source heat pumps work?

Geothermal heating and cooling draws on the ground temperature, which, if you dig down deep enough, is a consistent 55_лјF all year. Geothermal systems take advantage of that consistency to either transfer heat into or extract heat out of the home and into the ground. The direction of the heat transfer depends on the season.

Ground Heat Exchanger

The transfer of heat is made possible by a ground heat exchanger, a piece of the GSHP that has direct contact with the ground. The heat exchanger works in one of two ways. In the first instance (for cold weather), the exchanger extracts heat from the top layer of earth's crust. The other mode is for warm months: the exchanger extracts heat from a building and transfers it to the ground. There are three types of heat exchangers:

1. Closed loop system

The most common type of ground source heat pump system, a closed loop system, uses a contained network of underground plastic piping. The fluid in the pipes circulates, transfers heat, and flows back to the heat pump in a continuous loop. These systems are typically a bit more expensive to install than open loop systems, but require less maintenance and do not use groundwater resources.

2. Open loop system

Open loop systems use the water itself as the mechanism for heating and cooling the home. They're connected directly to a well or another groundwater source. The water is pumped through the system and into the heat pump, then used for heating or cooling. The used water is then drained into a pond, re-injected into a well, or something similar.

3. Direct exchange (DX) system

Direct exchange (DX) systems are a very efficient option for geothermal heating and cooling. DX systems differ from both open and closed loop systems in that they use copper tubing (a highly heat-conductive material) filled with refrigerant for heat exchange. The heat is transferred directly through the surface of the copper, which cuts down on any transfers that would result in heat loss.

Financing your switch to a GSHP

We want to help your switch to efficient energy by making your geothermal upgrade financially possible. Our Property Assessed Clean Energy (PACE) financing is making clean energy upgrades more affordable than ever. Thousands of happy homeowners across the state are reaping the rewards of CaliforniaFIRST financing, which include:
  • 100% financing. No out-of-pocket costs

  • Flexible repayment terms: 5, 10, 15, 20, or 25 years

  • Fast in-home approvals

  • Borrow up to 15% of property value

  • No prepayment penalty and free re-amortization

  • Balance may transfer to new owner upon sale

  • ...and more

Be sure to check out our other eligible products and projects for clean energy and water conservation. Interested in a ground source heat pump for your home heating and cooling? Get started by filling out a form or checking your eligibility for our financing!