There’s an invaluable energy source buried right in your own backyard: the earth itself. Forget oil or gas, geothermal systems tap into the relatively consistent temperatures of your yard, pond or well. This ingenious technology runs on electricity but uses the earth’s thermal energy to pre-condition refrigerant used to heat and cool your home so you can enjoy higher energy efficiency inside – no matter how extreme the weather gets outside.
Energy Source Options
In ideal conditions, an open-loop application can be the most economical type of geothermal system. These use groundwater from a well as a direct energy source.
If enough land is available horizontal loops can be installed. One or more trenches are dug using a backhoe or chain trencher. HDPE pipes are inserted, and trenches are backfilled. The more pipe per foot of the trench, the shorter the trench can be. Trenches range from 100 to 300 feet.
Vertical loops are installed if land space is limited and/or soil content is not conducive enough for horizontal loops. Installing vertical loops requires the use of a drilling rig. Multiple holes are drilled (depending on the size of the home) about 20 feet apart. A double pipe connected by a U bend at the end of the pipe is inserted in the hole. The hole is then filled with grout to provide good contact around the pipe and to seal the hole. The pipes are connected by a header system a few feet below the ground, which are then brought in through the foundation of your home and connected to the unit. The typical drilling depth is 100′-200′.
If you have access to an adequate size body of water close to your home, a pond loop can be installed. A series of earth loops are coiled and then sunk to the bottom of the pond. Typically a 1/2 acre with 8′ depth is usually adequate. Ideally, the body of water needs to be within 200′ feet of your home. If the pond is further than the recommended 200′, the benefit of using a pond loop is greatly reduced because of trenching, materials, and pumping costs.
