Ground Source Heat Pumps
Ground source heat pump power graph.
Why Ground Source Heat Pumps?
Ground Source Heat Pumps (GSHP) are more efficient than an Air Source Heat pump. The ground, from which they take their energy is a more stable source of energy than the air.
The performance from a GSHP depends on the type of ground collectors used to extract the energy. There are four types of ground collector commonly used in the UK.
The average temperature of the water in the ground collector differs for each type.
Horizontal Loop – Pipes are laid about 1 metre below the surface in trenches. Average water temperature 0oC – 6oC
Vertical Loop – Pipes are placed in bore holes at a depth of up to 200 metres. Average water temperature 10oC
Pond Loop – Pipes are coiled up and placed in water (pond, lake or river). Average water temperature 7oC
Open Loop – Fresh water is sucked in and discharged back in to a water course. Average water temperature 8oC
How they work
A GSHP uses the variable energy found in the ground or water, at a depth of around one to two metres. Inside the pipework is an anti-freeze solution.
This fluid, having increased in temperature, passes into a heat exchanger called the evaporator.
Typical average UK winter ground temperatures tend to be around 4°C or 5°C (horizontal loop). The heat pump boosts this low energy via its refrigeration circuit to a usable level for the provision of heating and hot water for the home.
The now slightly warmed refrigerant gas is compressed to a liquid which dramatically increases the temperature of the refrigerant.
The hot refrigerant liquid is then passed through another heat exchanger which is then used to warm the system water (Underfloor Heating or Radiators).
This second heat exchanger is called the condenser.
In order to start the cycle again, the refrigerant liquid must be converted back to a gas and this is done by the expansion valve.
How varying water temperatures affect the performance
The output from a GSHP is not fixed and it will vary depending on certain conditions. The certified output of a GSHP is measured for a ground inlet temperature of 0°C and a heated water temperature of 35°C.
However, if the inlet temperature falls or the heating water temperature rises then the output of the GSHP will fall.
All Radiant Heating Solutions partners heat pumps can be ordered in Heat and Cool models if required.
The cooling process simply reverses the refrigerant gas circuit. This is ideal when summertime cooling is required. Note - the cooling aspect is not supported by the RHI scheme.
We also have special models that capture the waste heat in cooling mode to heat the hot water tank.
Why our Ground Source Heat Pumps?
We have the technical know-how plus with over 25 years experience. We have built up a wealth of knowledge on energy efficient heating systems.
We know how to correctly size a heat pump in order to give the right amount of heat for ANY building, throughout the year.
We know how to make a heat pump work with ANY type of heating system.
We know how to link a heat pump in with other heating plant heat sources for complete system integration schemes.
Right for our climate
Radiant Heating Solutions partners heat pumps are perfectly suited for the UK climate.
All of these heat pumps we choose use the very latest refrigeration technologies.
Our single phase units have output ranges from 4kW to 22kW with single direct scroll or inverter driven compressors.
Our 3 phase units range from 8kW to 130kW. All of them can do heating and hot water and some can also be specified to do cooling if required.
What you get at a glance
All our heat pumps use direct scroll or inverter driven compressors with R410a refrigerant gas, 316 grade stainless steel heat exchangers and micro-processor controls.
The output from the heat pumps will always be sufficient for full load heating and hot water. Many are also fitted as standard with water circulation pumps.
Our partners heat pumps are easy to install by competent heating engineers.
We can also offer our own installation team to ensure full MCS compliance. Contact us
It is very important to size the heat pump correctly for the job it is going to do. In our comprehensive range there will be the correct sized unit for your project.
The outputs from our partners machines are based on a ground temperature of 0°C and a heated water flow of 35°C.
This is the European standard measurement for heat pumps and will normally be displayed as B0/W35.
When comparing different heat pumps it is important to make sure that the stated output always relates to this standard.
The performance of a heat pump is referred to as the co-efficiency of performance (COP). This in simple terms is the relationship to the amount of energy used to the amount generated.
If the heat pump uses 1kW of electricity and produces 3kW of heating water the COP would be 3.
The performance of a ground source heat pump may vary according to the outside temperature and the heating water temperature.
Ground Source Heat Pumps integration
Ground Source Heat Pumps can be linked to just about any other type of heat generation equipment. This makes them well suited for adding on to an existing heating system that uses a normal boiler.
For new or upgraded systems, the possibilities are endless. However, this type of integration requires careful planning.
For full details you can visit our System integration page
Types of integration
There are two types of integration, hybrid and system integration.
With hybrid integration the ground source heat pump is linked into an existing central heating system. This will require a small additional buffer tank that links into the main flow/return pipes of the boiler.
Both boiler and heat pump can run the heating and hot water either together or separately.
With the hybrid system the ground source heat pump works with the boiler. This can be used where the building has a high heat loss and during cold weather the heat pump cannot cope.
Sometimes this is because the heat emitters (radiators) need a much higher temperature. In this case the heat pump would stop and the boiler would start. For a more diverse setup you need the full system integration.
Note- For the RHI scheme heat metering will be required.
With a full system integration design, you can have the ground source heat pump to carry out any function to suit your requirements. You could just have it doing the underfloor heating where it will be most efficient or linked to any other part of the system.
The ground source heat pump can link in with solar thermal and/or solar PV, oil or gas boilers and wood stoves.
It can provide heating (and cooling via fan coils) for the whole building.
Putting together an integrated system can be quite complex and if you are unsure about how to do this, we can design the system for you. Contact us
Note - For the RHI scheme heat metering will be required.
You will get full plumbing and electrical drawings together with a quote for the equipment and installation.