Build Your Own House

Geothermal Heat Pumps-Closed Loop-Pond or Lake

Summary: The pond closed loop geothermal heat pump is the least expensive closed loop system to install as you can usually avoid expensive drilling.

“Hi Carl, I am building a log home on our property (approximately 3000 sq.ft.)

I was wondering if geothermal was the way to go.

We are going to put a pond in at the same time as the new build and thought about the pond for the coils.

We also were checking to see if there are any rebates from the government for the energy saving geothermal heating system?

I can’t find anything online about this question.

Thanks a lot for your time, Mary”

Hi Mary,

If you build your pond deep enough you can use the pond water for your geothermal heat pump.

Be sure you make the pond at least 8 feet deep to minimize the risk of the water freezing.

The water pipes that will be supplying ground temperature water to the geothermal system will be coiled into circles at least eight feet under the pond’s surface to prevent freezing.

Image courtesy of Energy Savers, U.S. Department of Energy |

As the principle of heat pumps relies on an ambient source of warmth, and unfrozen water is above 32 degrees Fahrenheit, your pond should be an excellent source of this warmth, providing you an efficient central heating and central cooling system.

Be sure to read my article on Geothermal Heat Pumps as well as the one on Heat Pumps.

Good luck, Carl Heldmann