Ground Source Heat Pumps Scotland – Discover Natural Warmth
We’ve installed many ground source heat pumps in Scotland (GSHPs) which operate in a similar way to air source heat pumps, but take their heat from the ground. They tend to be installed in one of two ways.
- One method, which requires large amounts of space, is to install a “slinky”, or network of horizontal piping, under the surface layer of soil outside the building.
- Where space is at a premium, GSHPs can be installed in vertically bored holes. In both cases the piping contains a liquid which, after being warmed by the earth, enters the heat exchanger and transfers heat from the ground to a second medium, usually water, which is then used to heat the building.
How do the pumps get heat from the ground?
Ground source heat pumps use the soil or groundwater as the heat source.
- In the evaporator (heat exchanger) the energy transfers from the cold medium to the refrigerant.
- The refrigerant will then evaporate.
- The refrigerant is transported in the circuit by the compressor to increase the pressure and temperature of the refrigerant.
- In the condenser (heat exchanger) the refrigerant cools and condenses.
- The energy is then transferred from the refrigerant to the heating system of the house, hot water system or air system
- The expansion valve regulates the mass flow of the refrigerant to maintain the pressure difference between the high pressure and the low pressure side.
Surface Collectors
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 earth collector may not be sealed off under any circumstances, i.e. by buildings, asphalt or concrete. Earth collectors do not require a permit. Installation depth is approx. 20 cm below the local frost line.
Ground Collectors
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 mixture of water-glycol circulates in a closed circuit (similar to the cooling system of a car). Depending on the necessary size of the heat pump unit a specialized company ascertains the depth and amount of bore holes in which the u-shaped plastic tubing is installed and pressed, in order to achieve good heat transfer.
Contact us for the no obligation quote for supply and installation of the ground source heat pump or any of our renewable energy services in Scotland.
