Evergreen State Heat & AC has been installing Geo-Thermal systems throughout greater Snohomish County for over 20 years. Our service technicians and estimators have been IGSHPA certified to ensure that we are able to evaluate your individual situation and make a determination whether Geo-Thermal is the best fit for you.

What is a "geothermal" system? It takes advantage of the Earth’s ability to store vast amounts of heat in the soil ("geo" means earth and "thermal" refers to heat). This heat energy is maintained at a constant temperature (50°F to 70°F depending on latitude) in the soil and near-surface rocks.

Geothermal heating systems, also called ground-source heat pumps, "capture" this steady supply of heat energy and "move" it from the Earth and through a home or building. Basically, once installed, a home or building owner will use much less energy, save money each month, and reduce the amount of pollution produced by fossil fuel systems.

A heat pump is a mechanical device that transfers heat from one source to another. Ground-source units pull heat from the earth and transfer it to homes or buildings. Heat pumps (despite their name) can provide both heating and cooling. The cooling process is simply the reverse of the heating process: heat is taken out of a building and returned to the Earth.

Typical ground-source heat pumps transfer heat using a network of tubes, called "earth loops." Basically, the loops are filled with either water, refrigerant or an anti-freeze solution. They run through the ground in the vicinity of a building and the liquid absorbs the Earth’s heat energy. Then, this warmed liquid is pumped back through the system into the building. This process provides heat to the building space. Once the fluid passes through the building and transfers its energy, it flows through the loop system back to the Earth and the process repeats itself.

In the summertime, these systems "reverse" into cooling mode. Technically, the system does not "run backwards." Instead, a series of valves enables the system to switch the "hot" side and the "cold" side. The heat from the building is transferred to the liquid in the loop and this liquid is pumped back into the ground. When the ground source heat pump is in cooling mode, it usually has an excess of warmed liquid in the system. This liquid can heat water for the building and basically eliminate the use of the hot water heater during the summer months.

It's the very heart of a geothermal system. It's what actually transfers heat to and from the ground. And it's the single biggest advantage a geothermal system has over ordinary heating and cooling systems.

Earth loops come in two basic types:

• Closed loops, made of durable, high-density polyethylene pipe, are buried in the earth or submerged in a lake or pond. They transfer heat by circulating a solution of water and environmentally safe antifreeze through the system.
• Open loops use groundwater pumped from a well as a heat source.

The decision of which loop configuration to use depends on the terrain, the cost of trenching or drilling, the availability of quality groundwater and the availability of land. Evergreen State Heat & AC estimators will help you make the most efficient and economical choice.
To see more about the Geo-Thermal systems that we install, please visit www.waterfurnace.com