Geo-thermal

Geo-thermal is an increasingly popular alternative energy solution. Geo thermal heating and cooling systems provide an effective way of using the constant temperature of the earth to regulate the temperature of our homes and offices. Even in colder climates, once you get a bit below the frost line the temperature of the earth remains surprisingly constant.

These geo thermal systems can work in a number of ways. One way is to excavate the ground and lay down coils that you cover up again. Then fluid is cycled through them. In the summer the fluid is under pressure in the ground. The ground will absorb the heat. The pressure on the fluid is then released and it returns to the building and it will be very cold. Then air is blown across the coils inside the plenum of the furnace in order to extract the coldness. In the winter the reverse is true. The fluid is put under pressure inside the building and air is passed over the coils to absorb the heat. The pressure is then released on the fluid as it goes outside. It will then be very cold and the earth will absorb the cold from the tubing. These principles apply whether we are using well systems or bodies of water or even air.

Well systems usually require drilling two wells. With this system you use the water from one well and return it to the other well after extracting the warmth or coolness from the water depending on the season.

If we are using a body of water, for the geo-thermal system, the coils need to be suspended between the surface and the bottom. It needs to be below any ice formation during winter and far enough above the bottom to be clear of weeds.

The air to air heat pumps are the least efficient. They work well enough for air-conditioning during summer. In winter they work well until the temperature drops below about minus 10 degrees Celsius. After that there is not much warmth that can be extracted from the air even when the fluid is compressed. Usually electricity provides the back-up heat.

These systems can be used to heat water as well as heat or cool a building.

One of the criticisms is that geo thermal systems require electricity from an external energy source to power them. However, they are environment friendly in that they reduce the carbon foot-print.

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