The extremely high levels of efficiency are possible because a geothermal heat pump only uses electricity to move heat, not produce it. A geothermal unit typically supplies 4 kilo watts of heat for every kilowatt of electricity used. Three of these kilowatts of heat come directly from the earth itself, and are clean, free, and renewable. Overall, geothermal technology offers the highest cooling efficiency available in the industry.

Geothermal heat pumps also provide higher comfort levels than traditional space conditioning equipment. By using a relatively warm source of heat such as the earth, supply air temperatures are significantly higher in the heating mode than traditional air-source heat pumps. Geothermal heat pumps also cycle much less often than fossil furnaces, creating a consistent indoor temperature with comfortable relative humidity.

The environmental advantages of geothermal systems have caught the eye of governmental agencies such as the Environmental Protection Agency (EPA) and the Department of Energy (DOE). Because it is lowest in CO2 emissions, geothermal technology provides a solution to global warming by primarily using the natural energy of the earth. In contrast, traditional space conditioning systems depend upon the exploitation and burning of fossil energy sources with the resultant greenhouse gas emissions.

Low life-cycle costs are provided by the low operating and maintenance costs of geothermal systems, even when the higher initial installation costs are considered. In new construction, monthly energy savings typically exceed the increased mort gage payments. Therefore, cash flow can be positive from the start. In retrofit systems, a buyer who purchases with cash usually realizes a return on in vestment well above certificate of deposit rates. And, with equipment life exceeding 20 years, a GT-G Series unit is a lasting in vestment.

Electric utilities, recognizing the dual benefits of high efficiency and low electric peak demand, may provide incentives to purchase these systems.

Before choosing a geothermal system, many application factors must be evaluated, including:

• ground water availability and quality

• loop installation costs

• land area available

• sub-soil conditions

• local codes

• owner preferences

Haley Mechanical has the expertise and computer software to determine the best type of system.

Closed Loop Systems consist of an underground heat exchange network of sealed, high strength, poly ethylene plastic pipe, and a Flow Controller pumping module. When cooling, the loop fluid temperature will rise, and rejected heat is dissipated into the cooler earth.

Conversely, while heating, the loop fluid temperature falls, and heat is absorbed from the earth. Bryant Flow Controller pumping modules utilize low wattage pumps to circulate the water/antifreeze fluid within the piping system. The plastic heat exchange loop is closed and thermally fusion-welded at all connections in the same manner as natural gas distribution lines. Closed loops do not require a ground water supply or drain, and they are not subject to mineral build-up.

Closed Loops can be installed in vertical or horizontal configurations or submerged in a pond or lake. When designed properly, all three alternatives operate with similar efficiency. Bryant high density poly ethylene plastic pipe is used for all closed loop installations. Pipe connections are heat fused to form joints that are stronger than the pipe itself. Bryant loop piping has a life expectancy in excess of 50 years.

Horizontal Loops are often considered when adequate land space is available. The pipes are placed in trenches, excavated by a backhoe or chain trencher to a depth of 4-6 feet. Depending on design, from 1-6 pipes are installed in each trench. Multiple pipe and coiled “slinky” configurations are often used to conserve land requirements and reduce overall installed loop costs.

Horizontal boring technology can also be used to install u-bend loops 10-15 feet deep with minimal landscaping disruption. Trench lengths range from 100-400 feet per system ton. Trenches must be spaced from 6-10 feet apart. The overall land area required ranges from 750-1,500 square feet per system ton.

Vertical Loops are the ideal choice when available land area is limited. Drilling equipment is used to bore small-diameter vertical holes. Two pipes joined together with a u-bend fitting are inserted into the vertical bore. Bore hole depth ranges from 100-300 feet per system ton. Bores must be spaced from 10-15 feet apart and properly grouted. The land space required ranges from 100-200 square feet per system ton.

Pond (Lake) Loops are very economical to install when a body of surface water is available, because excavation costs are mostly eliminated. Coils or “slinky” mats of pipe are simply placed on the bottom of the pond (lake). In most cases, 1/4 to 1/2 acre of water surface, with a minimum depth of 8-10 feet, is needed for a typical residence.

Open loop systems utilize ground water as a direct energy source when good quality water is available at a reasonable pumping depth. A well must have enough capacity to deliver a minimum of 1.5 gpm per system ton during peak operation. Ditches, field tiles, ponds, and streams are the most common discharge systems. Re injection or semi-closed recirculation wells can also be utilized in some regions. In ideal conditions, an open loop application can be the most economical type of system to install.