Heat pumps are based on the principal of exchanging heat between two environments of different temperatures; they can either heat or cool a building, depending on how the circuit is set.
Installing a ground source heat pump can lead to a reduction in energy consumption of up to 80%. The reason for this is that a ground source heat pump uses the ground, surface soil or nearby lake or spring as its main energy source, and all these kinds of energy are free of charge.
Although the heat pump doesn't pay for itself in the first month, you will notice the financial benefits the first month after installation because your heating bills will be so much lower.
A heat pump works on the same principal as a fridge, by using a refigerant gas which reaches boiling point at very low temperatures even winter ground temperatures will cause the refrigerant to boil, the hot gas is pumped through a heat exchanger where the energy is transfered to the heating system in the building.
Ireland's moderate climate is ideally suited to deliver excellent performance from this technology.
Heat pumps work particularly well with underfloor heating because they deliver the ideal temperature for the efficient operation of an underfloor heating system, giving savings of up to 70% when compared with oil or gas systems in a similar installation.Types of Ground Heat Pumps
Surface Collector During the summer, solar heat is stored in the soil. This is either directly absorbed as insulation or as heat from rain and the air from the near-surface layer of the soil. Using this energy for heating is a cost effective method. The highest yield can be obtained from soil with high water content. The heat is extracted from the soil by means of buried plastic tubing. An environmentally-friendly, non-freezing emulsion of water and glycol circulates in the tubing. The soil above the surface collector may not be sealed off under any circumstances, i.e. by buildings, asphalt or concrete. Installation depth is approx. 20 cm below the local frost line.
Ground Probe or Bore hole In the lower subsoil of the so-called "near-surface geothermal layer" lies a heat source that can be utilized all year long, which has an almost constant temperature. It can be used for every possible building type, large or small, public or private. Depending on the region it is also referred to as, "vertical absorption, ground spit or ground lance". It requires little space and the ground probe can be drilled on the smallest of plots. Therefore it is ideal for refurbishment or adaptation from a heating system fuelled by fossil fuels to the use of geothermal energy. As with a surface collector a refrigerant, mixture of water-glycol circulates in a closed circuit (similar to the cooling system of a car). In order to achieve good heat transfer the depth and amount of bore holes in which the u-shaped plastic tubing is installed and pressed, are calculated to match the size of the heat pump.
If ground water is available, e.g. a lake , stream or spring, and easily accessible, it can be utilized as a heat source due to the fact that it has a temperature of between 7 and 12 °C all-year round.