Geothermal (heating, air conditioning and hot water) provides comfortable heating and cooling for your home by using the below the surface temperature of the earth. Outdoor temperatures can fluctuate wildly from season to season. The temperature just 4 to 6 feet below the earth’s surface remains relatively constant throughout the year. A geothermal system utilizes these stable temperatures to provide free energy.
A geothermal system is made up of an indoor handling unit and a buried piping system called an earth loop. The earth loop pipes, made of polyethylene, can be laid under the ground vertically or horizontally, depending on the land available.
During the winter months the fluid in the geothermal system absorbs the ground heat and carries it inside. The indoor handling unit compresses the heat and then distributes it throughout the home. During the warmer months of the year the system pulls the heat from the home, carrying it through the earth loop and transfers it into the cooler earth.
A geothermal system transfers heat to and from the earth. No fossil fuels are burned to generate heat. Electricity is used to power the fan, compressor and pump.
There are 3 main parts to a geothermal system.
- Heat pump unit
- Fluid heat exchange medium, via a ground loop
- Heat delivery system consisting of ductwork and/or in floor heating tubes
The efficiency of these systems is rated by their COP (coefficient of performance). Most geothermal systems have ratings of 3.0 to 5.0. What this means is that for each unit of energy used to run the system 3 to 5 units are supplied as heat.
Little maintenance is required for geothermal HVAC systems. When properly installed the loop can last well beyond a lifetime. The indoor components which include the fan, compressor, and pump can last for many years with proper care. In most circumstances regular checks, filter changes and yearly coil cleaning are the only required maintenance.
With more than 60 years of use throughout Europe and North America geothermal systems have a proven track record. Working with nature, there are no green house gas emissions produced. As part of the Green building movement, 30 to 40% of the housing market is driven by environmentally friendly alternatives which includes geothermal heating, cooling and hot water systems.
Despite contrary evidence there is still misinformation about geothermal systems.
MISCONCEPTION 1: Geothermal systems are not a renewable technology because they use electricity.
THE TRUTH: Using only one unit of electricity, a geothermal system can move as much as 5 units of heat from the earth to the building.
MISCONCEPTION 2: When compared to geothermal systems, wind power and solar power are better renewable resources.
THE TRUTH: Dollar for dollar, investments in geothermal energy are more effective than solar or wind power investments.
MISCONCEPTION 3: You need a lot of land to install the piping for the earth loop.
THE TRUTH: Depending on the situation the loop can be installed vertically on small city lots.
MISCONCEPTION 4: Heat pumps are noisy.
THE TRUTH: There is no equipment outside making noise such as an air conditioner and the interior equipment runs very quietly.
MISCONCEPTION 5: Geothermal systems wear out with time.
THE TRUTH: Earth loops last for generations. The heat exchange components are protected indoors and can last for decades. When it does need to finally be replaced you only need to replace the indoor components.
MISCONCEPTION 6: Geothermal systems only work in heating mode.
THE TRUTH: These systems work just as well cooling the house. The system works by removing the warm air from the home and transferring it to the earth.
MISCONCEPTION 7: A geothermal system cannot multitask. For example, it cannot heat your water and your home simultaneously.
THE TRUTH: The system can be designed and engineered to preform multiple tasks, including heating your pool!
MISCONCEPTION 8: Geothermal systems use refrigerant in the lines.
THE TRUTH: All of our systems use simple water and environmentally friendly antifreeze in the lines.
MISCONCEPTION 9: Geothermal HVAC systems use and waste large volumes of water.
THE TRUTH: A closed loop (most common) geothermal system does not consume any water.
MISCONCEPTION 10 Without federal and local tax incentives geothermal technology is not financially feasible.
THE TRUTH: Geothermal systems cost more to install than traditional HVAC systems. Geothermal systems last longer with less maintenance and are more efficient. Incentives reduce the installation costs and reduces the time period for your investment will pay for itself.
Information summarized from an article by Jay Egg.