KEC Geothermal Ground Source Heat Pumps

The KEC utilizes a very efficient mechanical system known as Ground Source Heat Pumps, or more commonly and incorrectly referred to as Geothermal.  True Geothermal heat comes from hot springs in the Earth and looks like this:

Ground Source Heat Pumps are used to efficiently heat and/or cool a building and looks more like this:

Dissapointing I know, sorry for that.

So what is it and how does it work?  I can share what I have learned from installing the system at the KEC, speaking with the project mechanical engineer, and doing some of my own research online.  These visuals were very helpful for me to understand.

Geothermal heat pumps don't create heat by burning fuel, like a furnace does. Instead, in winter it collects the Earth's natural heat through a series of pipes, called a loop, installed below the surface of the ground or submersed in a pond or lake. Fluid circulates through the loop and carries the heat to the house. There, an electrically driven compressor and a heat exchanger concentrate the Earth's energy and release it inside the home at a higher temperature. Ductwork distributes the heat to different rooms.

In summer, the process is reversed. The underground loop draws excess heat from the house and allows it to be absorbed by the Earth. The system cools your home in the same way that a refrigerator keeps your food cool - by drawing heat from the interior, not by blowing in cold air.

The Consumer Energy Center site was very helpful.

Here are some images from the design and installation at the KEC site.  During preconstruction we performed a test well to accurately measure the flow rates and temperates of our specific site so the assumed design could be fine tuned.  The ground temperatures range between 51 and 53 degrees.  The design for the KEC called for (25) wells 450' in depth.  Each well has a plastic pipe loop that goes down to the bottom of the well and then back up.  There is over 4 MILES of piping associated with this work!!  Sima Drilling performed this work.

[click to enlarge]

[well drilling]

[well drilling]

[piping at wells]

[piping from well field to building]

[piping from well field to building]