What is a ground source heat pump system?
A ground source system is where a heat pump inside the property and heat is extracted, generally from the ground. It can also be generated from lakes, ponds and rivers but the vast majority is from the ground.
How is the heat generated?
The heat is generated mostly from the ground and there are two ways of doing that. One is from a bore hole, which is a hole that is drilled by a machine that generally goes down 80-100 metres. The machine that is used bores down and a factory made pipe with a u-bend in it is then put down. This is a true geo-thermal heating system and a fluid that is a mixture of glyco and water is sent down, picks up the heat down from the earth, brings it back up, multiplied up by the ground source heat pump itself and can then go into the buffer cylinder.
What if I have under floor heating..do I need a buffer cylinder?
Properties with under floor heating generally don’t need a buffer cylinder as it is going straight through your under floor heating and heating your hot water cylinder.
What other approaches are there for ground source heat pumps?
The other approach to ground source systems, which need a little more land, is where you put loops in the ground in trenches that are just below about a metre in depth. Generally you are looking at 450-600 metres worth of loops which are divided into 3 or 4 loops. All of the loops are joined into a manifold inside a chamber, with a pair of pipes coming from that manifold to your ground source heat pump.
Wouldn’t that make it look untidy?
Once the ground source heat pump system has been installed, all that will be seen is the cover of the chamber. All of the ground within your garden or field will all be restored after installation as well.
What about the actual heat pump?
The actual heat pump itself is generally smaller than a normal fridge. The pump is about the same width of a fridge but may be a little bit deeper. However, it will only come up to about chest height.
How efficient is a ground source heat pump?
The COP, Coefficient Of Performance, of a ground source heat pump will be up into the 8 and a half’s, compared to the 3 1/2 to 4 1/2 of an air source heat pump. This makes a ground source heat pump up to about 850% efficient.
How much will it take to install?
A ground source system will cost a great deal more to install than an air source unit. This is because a great deal more work is involved in the installation.
Are heat pumps supported by the RHI?
Both the air source heat pumps and ground source heat pumps are supported by the RHI, Renewable Heating Incentive. The payments will vary between the air source and ground source heat pumps due to the cost of installation. For the domestic scheme, you will be looking at a 7 year period of payments and within 3 or 4 years, you will have the cost of installation payed for.