With a ground source heat pump you can use the heat that is present in the ground to heat your home. It is an extremely efficient way of heating if you sttep over the necessary investments. In this article you can read how a ground souce heat pump works, what systems there are and what you can expect regarding the investment.
Ground Source Heat Pump
How does a ground source heat pump work?
The ground contains heat. This heat comes from both the sun and of the magma that is deep in the Earth. This heat is called geothermal heat. When we lay a pipeline network in the soil, this geothermal heat can be used to heat the water in the pipeline network. The temperature of this is not yet high enough to heat the house, hence that you need a pump that together with a compressor, evaporator and condenser, further increases the temperature. Using a heat exchanger the heat is subsequently used for the central heating system in the house. The heat pump used for this process needs a (small) amount of electricity. Two types of ground source heat pumps
A geothermal system uses a loop of pipes that extractss the heat from the ground. Depending on the available space around the house, the pipes are laid horizontally or drilled in the ground vertically. Each system has its own advantages and disadvantages with accompanying costs.
In this method, the tubes are positioned horizontally at least one and a half meters deep in the ground. Starting from this depth the ground is frost free and warm enough. The surface that is needed, is about two times the living space. On average, a piece of land of about 200 to 400 square meters is needed. When the pipework layout is too small, there is a risk that the liquid in the tubes is going to freeze. To counter this, more anti-freeze liquid is needed with the disadvantage that this makes the liquid thicker and harder to circulate. The pump will therefore use more energy making the efficinecy drop. A pipework layout which is too small will in other words mean that is is likely that the investment will not be earned back. Advantages of a horizontal pipe layout: A horizontal network provides a fairly consistent yield and a high return.
Disadvantages of a horizontal pipeline network:
Ground source heat pump with vertical probe
A vertical placement is chosen when there is too little ground surface to do this horizontally. There is drilling done in the deep of the ground in this system which, depending on the soil composition and the desired power of the system, range from 25 to 150 meters deep. Starting from 50 metres deep is the temperature that is constant. Obviously in the Scottish land and in many other areas in the UK this is impossible because of the rocky underground. If succesfull, seasonal changes will hardly influence the temperature making the yield of the ground source heat pump Glasgow constant throughout the year. In the drill holes plastic hoses are layed that are connected to the evaporator of the ground source heat pump.
Advantages of a ground source heat pump with a vertical probe
– The seasons have no effect on the return, so a constant high efficiency. – There is little land needed. Disadvantages of a ground source heat pump with vertical probe
– Depth drillings are pretty pricey. – It is difficult to calculate the required drilling depth in advance. Efficiency of a ground source heat pump: soil composition
The efficiency of this geothermal system depends largely on the amount of heat that can be taken up from the soil. This doesn’t only apply not to the depth but also to the type of soil. TThe efficiency of a ground source heat pump in a clay soil is no less than twice as good than is the case with dry sandy soil. In addition to a suitable soil composition, it is absolutely necessary that the property well insulated. That applies, of course, for all systems, but if you are planning to do an investment in a grouns source heat pump, you may want to look a underfloor heating systems as these are the most efficient in the long term. Ground source heat pump price
For a heat pump with a horizontal pipeline network you should consider costs starting from £10000. With a vertical network you nee to add at least £4000 to that for the actual drilling. This in addittion to the pump installation of £7000 to £15000.