Energy Efficiency

Vertical & Horizontal Loop Geoexchange Systems

If there is an adequate amount of land available, and the soil conditions are good to a depth of five feet, closed loop horizontal piping systems can be installed in trenches four to six feet deep. The length of the piping depends on the heating and cooling capacity needed by the building.

The piping system is connected to a network of water-to-air heat pumps inside the building. The fluid circulated through the underground loop is a nonhazardous or biodegradable solution. Multiple layers of piping can be placed in the same trench if there is at least one foot of soil between the layers of pipe. Typically, a 300 foot trench with 600 feet of pipe is installed to provide one ton of heating and cooling capacity.

Closed Loop Vertical System

If there is a limited amount of land available, a vertical loop system can be used. This is the most common configuration for larger projects. Loops of piping are inserted into deep vertical bore holes. The holes are then backfilled with a sealing solution, such as grout.

A bore hole 150 to 200 feet deep containing 300 to 400 feet of pipe typically provides one ton of heating/cooling capacity. Soil moisture, soil type, pipe size and grout material affect the actual heat transfer.

Facts

• GeoExchange systems have a number of significant energy and environmental benefits. For every 1 kW of electricity (plus 3 kW of geothermal heat moved from the earth) 4 kW of heat can be delivered to a building.
  
• GeoExchange systems are relatively simple compared to other more traditional heating systems. There are no elaborate control systems, boilers, condensing units or cooling towers. Each unit operates individually, allowing either heating or cooling to occur as needed.
  
• A GeoExchange system can reduce a building’s energy consumption and costs by 30%.

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