For the most part, construction techniques used to build today’s home have pretty much arrived. One emerging technology, geothermal heating and cooling, is sure to change the way we heat and cool our homes forever.
When you buy a home that incorporates a geothermal system, you will own a home that uses renewable energy. Geothermal systems promise tremendous savings over the long term as compared to such traditional sources of energy and you will have the peace of mind that you are a front runner of environmental sustainability. There is plenty of geothermal energy; it is always available, right beneath your feet!
How does geothermal work?
Simply put, geothermal systems move heat from one area to another. When you require heat, the geothermal system extracts heat energy from the ground, and moves it into the home. The exact opposite happens when you want to cool your home, with a flick of a switch; the geothermal system extracts heat energy from the air in your home and moves it into the ground.
At the heart of the system, inside your home, is a ground source heat pump. A series of fluid-filled underground pipes called a “loop” absorbs stored heat from the ground to the heat pump where it is converted into warm or cool air for your home.
The heating cycle
In the heating cycle, the refrigerant fluid in the loop absorbs heat from the underground and brings it to the ground source heat pump in the house. The ground source heat pump then heats the refrigerant fluid and sends it to a radiator of sorts. Air is blown through the radiator and then through the ductwork in your home to each room of the house.
The cooling cycle
The cooling cycle is basically the reverse of the heating cycle. The direction of the refrigerant flow is reversed. The ground source heat pump takes the heat from the air in the house and eventually transfers it directly into the ground.
Why use the ground for energy?
Outdoor temperatures fluctuate with the changing seasons but underground temperatures don’t. Four to six feet below the earth’s surface, temperatures remain relatively constant all year-round. A geothermal system capitalizes on these constant temperatures to provide “free” energy.
The ground represent a vast reservoir of renewable thermal energy stored from the sun. Geothermal energy is estimated to exceed all other energy sources combined by more than two thousand times.
At depths below 8 to 10 feet (2.5 to 3 meters), the earth's temperature remains at or near the average annual air temperature above. For every unit of electrical energy used by a ground source heat pump, a well-designed geothermal system can provide three to four units of heat energy to the building. This represents efficiencies of 300% to 400%. That means one unit of electricity produces up to 4 free units of energy from the ground.
Clean energy. No fossil fuels.
Unlike traditional ordinary systems, geothermal systems don’t burn fossil fuel to generate heat; they simply transfer heat to and from the earth to provide a more efficient, affordable and environmentally friendly method of heating and cooling. Typically, only a small amount of electricity is used to operate the unit’s fan, compressor and pump.
By their very nature, geothermal systems are environmentally friendly. Geothermal systems reduce the need to extract, transport, and burn fossil fuels, and require less generation and transmission of electricity than traditional heating and cooling systems. This translates into a direct reduction in the emission of pollutants and greenhouse gases and geothermal systems have none of the risks associated with carbon monoxide and open flames.
In short order, a geothermal system will pay you to own it
Because of their exceptional efficiency, geothermal systems are substantially less expensive to operate than tradition natural gas or electric resistance heating systems. “Annual energy savings for homeowners can be reduced from 30 to 70% in heating mode and 20 to 50% in the cooling mode compared to conventional systems” - Natural Resources Canada. The simple payback (the period of years before the savings in annual operating costs exceed the initial premium of an installation) ranges from 3 to 12 years. After that, it’s money in your pocket.
This article is written by or on behalf of an outsourced columnist and does not necessarily reflect the views of Castanet.