Why geoexchange?

One of the primary reasons geoexchange systems have gained popularity as a sustainable source of energy is their high level of efficiency.  Certain systems have the potential to be up to 400% efficient,  meaning they produce 4 units of heat for every 1 unit of energy they consume.  When geoexchange systems are powered by renewable sources of electricity such as solar, wind or hydro, they become truly sustainable sources of energy, using only the elements to condition a home.

Intro to geoexchange (or geothermal) energy:

Geoexchange systems use the earth’s constant ground temperature to act both as a source of heating and cooling for your home.  Geoexchange heat pumps transfer heat energy from the ground to your home in the winter, and from your home to the ground in the summer.  Rather than converting fossil fuels into heat, geoexchange systems use electricity to move “heat BTUs” between the earth and your home.

Geoexchange system highlights:

• There are over 250,000 installations in place in the U.S. today
• Local, state and federal tax incentives are available for geoexchange systems
• Payback typically occurs within 5-10 years depending on system size, home size, etc.
• New technologies have lowered the costs of systems and increased reliability and performance

Common components of geoexchange systems:

Earth loop- the earth loop is the method with which the heat pump transfers energy between the home and the earth.  Earth loops all use a liquid mixture as the medium of heat transfer between the earth and the heat pump, and can be open or closed loop systems.  In closed loop systems, a water/glycol solution is circulated through underground or underwater piping, allowing heat transfer to take place with the earth.  In an open loop system, an entire well or pond acts as the medium of heat transfer.  In the case of ground source heat pump systems, loops can be either horizontal or vertical depending on your site configuration and available space.

Heat pump- the heat pump uses the same process as a refrigerator or air conditioner to transfer heat between the earth loop to the house loop.

Distribution system- the distribution system may look a bit more familiar then the other two components of a geoexchange system.  This component simply takes geoexchange energy and uses it to heat or cool your home.  Distribution systems for geoexchange energy use the same basic principles as conventional boilers, furnaces, air conditioners, etc.  The difference comes from the source of heat- which in this case involves a heat pump rather than natural gas burners, heating elements, etc.  In the winter,  distribution system essentially takes the heat energy extracted from the earth and distributes it throughout your home in a useful form- including forced air heating/cooling, radiant heating, domestic hot water, snowmelt and pool/hot tub heating systems.