Geothermal
Conserves Today’s Energy

Jo Anne Peña

As home heating and cooling costs increase substantially, there is widespread interest in alternatives using renewable resources. Geothermal systems that directly harness heat from the ground are a viable resource to consider.

The Earth is the greatest solar collector in existence. Energy can be extracted from the ground 365 days a year. “Ground loops” are a way to take advantage of this. The sealed loops, a mixture of water with a small amount of ethanol that serves as antifreeze, are safe for the environment and will not contaminate ground water. The 200-foot ground loops are installed horizontally or vertically. Depending on climate, soil type, and available area, vertical loops are installed in 4-6 inch diameter boreholes, 15 feet apart in the form of a grid or wagon wheel. Horizontal loops are placed in a trench 6-8 feet deep in lengths of 200 feet, using single pipes.

The geothermal heat pump uses innovative technology to take the Earth’s free heat and boost it to usable temperatures for distribution of heating, cooling, and domestic hot water, using electricity as efficiently as possible. The heat pump moves energy according to the temperature of the atmosphere in winter or summer. One unit of electricity is able to produce 4-5 units of heat under any condition or time of day. Think of the heat pump as a refrigerator. Refrigerants have the ability to get extremely cold while remaining flowable. That’s the key! The 410A refrigerant can harvest heat from extreme cold. It is a non-ozone depleting refrigerant that is safe for the environment.

Heat pumps do not create energy; they move it from the ground to your building or from the building to the ground, depending on the season.

Geothermal heating and cooling systems consist of three main elements:

• The Underground Loops act as a heat exchanger. The ethanol/water solution passes through the loops and moves energy from the ground into the heat pump.
  
  
• The Indoor Heat Pump Unit gives up its energy to the surrounding area, condenses it back into a liquid, and uses the energy in the form of gas to heat or cool a home.
  
  
• The Radiant Heat System or Air-handling System takes the heated or cooled energy and moves it to individual rooms.

A Geo exchange system can cut energy costs by 60% or more compared to conventional systems. It can produce and reject 3-4 times more energy than it consumes. They also have the lowest lifecycle cost of any type of mechanical system. Plus, they are better for the environment because there is no consumption of fossil fuels, if the electricity required is renewably generated.

Photos courtesy Dahl Plumbing