Ground Heat Source Pumps

geothermal energyHow Do They Work?

Ground source heat pump systems do not heat a home by burning fuel. They collect heat from the Earth via a pipe or pipes buried in the ground. These pipes are called loops and contain a mixture of water and antifreeze. The fluid is circulated through these loops by an electric pump into a compressor and heat exchanger.  The heat from the fluid is transferred to a refrigerant with a low boiling point. This in turn causes the refrigerant to change to a gas, which is then compressed increasing its temperature. The hot gases flow around a heat exchanger and transfer heat to the heating system. As these gases cool they return to a liquid state and the whole process is repeated.

Is it suitable for my home?

There are several key elements to consider before deciding if a ground source heat pump system is suitable. Firstly do you have a suitable garden and, does it have access for the machinery needed to bore the holes? Because ground source heat pumps produce lower heat temperatures than traditional boilers, it is essential that your home is well insulated for the system to be cost effective. Under floor heating systems use lower water temperatures, and therefore work best with this system although radiators can also be used. If replacing a coal or electric heating system, you will save on your heating bills. For homes heated by gas, ground source heat pumps are not considered as a cost effective alternative.

The benefits

Ground source heat pump systems require little maintenance and are often referred to as fit and forget. They can reduce the amount of fuel your home needs and in turn reduce your carbon footprint. If you currently use heating oil there will be no more deliveries needed. As well as providing space heating some systems can produce your domestic hot water needs.

Costs and savings

The installation costs for a ground heat pump system range approximately between £9,000 and £17,000. The size of your home and how well it is insulated will determine the running costs. Heat pumps are powered by electricity, therefore they can be combined with a solar photovoltaic panel  array. This effectively could produce a zero carbon emission system, and a low running cost for maintenance only.


Ground source heat pumps have less components than conventional systems. They are durable requiring little maintenance. The loop buried in the garden is usually made of a high density plastic and is often guaranteed to last 25 to 50 years.

Source: wattwatt

Ground heat source pumps are relatively unknown compared to other renewable energy sources such as solar energy and wind power.  Geothermal energy for heating water is a possible alternative to solar water heating but the expense of geothermal heat pumps may be a limiting factor (see Geothermal Energy which also contains some information by a South African company that specializes in these systems).  In South Africa, not many homes have underfloor heating but cooling systems are in demand, especially in the Mpumalanga and Limpopo Lowveld.  The temperature differential of these systems can also be used to create a cooling effect.

Water and energy are linked so Water Rhapsody has incorporated Yes Solar Mpumalanga so that we can offer solar energy solutions in addition to our World Wildlife Award-winning water conservation systems.  Yes Solar is  an official distributor of German-made Solsquare solar water geysers that are SABS- and Eskom-approved and are installed by qualified solar installers.

Contact us for a free quote on a solar geyser, rain water tank,  rainwater harvesting system, grey water recycling system or water tank (we are Atlas Plastics and JoJo water tank dealers in Mpumalanga and Limpopo – best water tank prices in the Lowveld!).

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