The Earth Can Boost The Performance Of Your System

The design of the Earth Heat Exchanger depends on many factors, including local climate, ground composition, moisture content and temperature, and air conditioning and heating load. Typically it is a series of high density polyethylene pipe buried in one of several loop configurations below the surface of the earth or in a body of water through which water (sometimes mixed with anti-freeze) is circulated. The pipe used in the loop is fusion bonded and typically has a 25-50 year minimum warranty, depending upon manufacturer.

A prime source of system heat in winter is heat stored five feet or more below the earth's surface. When the building demand calls for heating, water pumped through the loop absorbs heat from the relatively warm earth. This heat is moved via the loop into the building where ClimateMaster Water Source Heat Pumps direct warm air to those areas calling for heat.

To cool, the heat pump (a compressorized refrigeration system) removes heat from the building and transfers it into the temperate earth via the loop. Because of the relative cool temperature of the earth, heat is readily and efficiently absorbed from the loop. This means that ClimateMaster Water Source Heat Pumps in a geothermal system can offer substantial operating savings over other types of air conditioning systems which must reject heat into hot outside air.

Since 1992, geothermal technology has been singled out as the primary HVAC technology which can be employed to meet     government and international guidelines for the reduction of harmful chemical emissions by 2005. The high efficiency and environmentally friendly nature of geothermal technology has secured its endorsement by the DOE, the DOD, the EPA, HUD, USDA, and many local utility companies.

Geothermal Earth Heat Exchanger

	Horizontal Ground Loop System: A Horizontal Ground Loop system is usually selected when adequate space is available and trenching can be easily accomplished. A series of parallel pipes are laid out in trenches 3 to 6 (.9 to 1.8 m) feet below the ground surface, then backfilled. Often the pipe is coiled in a slinky configuration to maximize the heat transfer capability of each trench. The amount of pipe and the size of the Ground Loop Field is based on ground conditions, heating and cooling requirements of the application, and system design.
	Vertical Ground Loop System: Where more appropriate, a Vertical Ground Loop may be installed in vertical bore holes 150 to 500 feet deep (46 to 152 m). Each hole contains a single loop of pipe. After the pipe is inserted, the hole is backfilled (or grouted). The number of loops required depends on ground conditions, air conditioning and heating load, and the depth of each hole. This design is well suited for retrofit applications where landscaping is already complete and minimum disruption of the site is desired. The completed loop is concealed below ground.
	Surface Water System: Because of the excellent thermal properties of water, a loop may be submerged in a series of coils beneath the water surface when an application is located near a lake or pond. Since the mass of a large body of water is thermally stable, a Surface Water System can be an excellent and cost effective application. The number of coils required depends on system load and design. The Surface Water System is a variation of the Closed Loop design and requires minimum piping and excavation.

Open Loop System: Where ground water is plentiful, an open loop may be utilized with WSHP Units. In this application, ground water is pumped through supply piping from the well to the building. Upon leaving the building, the water is pumped back into the ground via a discharge well. This design limits the amount of piping and excavation required. When ground water is used, an additional heat exchanger is often installed between the building water piping system and the ground water piping system.

Standing Column Well System: When appropriate, a Standing Column Well may be used. In this application, a 6" (.15 m) diameter standing column of ground water is used as the heat source. The column is cased with pipe down to bed rock. Temperate water is pumped from the bottom of the column and piped directly to the building. Upon leaving the building, the water is pumped back into the top of the column. Although this application does not rely on a pumpable supply of ground water, there must be sufficient ground water present to maintain the standing column of water. The depth of the column depends on system load and design.

Hybrid Systems: Under some circumstances, it may be desirable to incorporate a cooling tower into the geothermal design to reduce the cost of the ground loop and installed first cost. The hybrid system rejects excess heat into the air and thereby increases the cooling performance of the ground loop.