Geothermal heating is a practical and energy saving alternative for heating and cooling purposes. The ground or a nearby water source can be used as a heat sink in the warm months and as a supply of heat in the winter month.
Geothermal coils
Geothermal earth loops are made from high density polyethylene pipe. Geothermal pipe that is used in geothermal cooling and heating systems is specifically designed with amazing physical and thermal features. Geothermal pipes are designed to withstand the stress of being buried deep within the ground or submerged in water. A succession of these pipes is referred to as a “loop”; these pipes are connected to the geothermal system’s heat pump and carry fluid between the ground (or a water source) and the pump.
Types of geothermal loops
According to the geology, the hydrology and the land availability, different types of geothermal energy sources will be installed. Such features as the composition of the soil and rock will be taken into consideration when planning the geothermal system. For example, rock affects heat transfer, therefore the density of the rock on the property will be a key factor to consider when deciding what type of geothermal loop to use. Other factors such as the presence of water, the depth and the volume, and water quality will be considered.
Closed loop; in this type of geothermal system, a water based solution is circulated throughout a small diameter loop. A closed loop system can be set up vertically or horizontally in the ground, or submerged in water. This system is the most popular. Horizontal loops are often used in areas where sufficient land surface is available. Geothermal pipes are positioned within channels dug in the ground which vary from 100 to 400 feet in length.
Vertical loops are a perfect solution when existing land surface is limited. Small diameter holes are dug in the ground using drilling equipment. These holes range from 75 to 300 feet in depth.
Pond (lake) loops. When a body of water is available, this type of geothermal solution is the most economical to install as the need for drilling equipment is essentially removed as the geothermal coils of pipe are positioned at the bottom of the pond or lake.
Open loop. An open loop system uses a near-by water source to circulate water. In ideal conditions, an open loop application can be the most economical type of geothermal system.
Plastech Plus Inc. supplies a complete range of drilling products and geothermal accessories that are used in geothermal heating and cooling installations. PVC Plus Drilling can supply you with geothermal fittings, geothermal grouts and geothermal HDPE pipes.
http://www.energysavers.gov/your_home/space_heating_cooling/index.cfm/mytopic=12670
http://www.toolbase.org/Technology-Inventory/HVAC/geothermal-heat-pumps
http://www.igshpa.okstate.edu/geothermal/faq.htm