There are two types of heat pump one use the ground and the other uses air.
The temperature about 1metre below the ground’s surface is a steady 5-7 *c all year round. Collectors in a lake fair even better.
Ground loops are buried into the ground and a solution is pumped through these to a ground source heat pump which uses this energy to provide heating temperatures of about 45- 50*c. This is done through a process of refrigeration. This temperature is perfect for under floor heating which is a much better product for space heating so is the ideal partner to renewable energy.
Heat pumps are linked to the outside temperature (weather compensated) so once set up require little adjustment. As the temperature goes down the heat pump works a bit harder to maintain a steady room temperature and vice versa as the temperature goes up.
A heat pump requires about 2.5 x the property footprint for the collectors and where this is not available a bore hole can be used. A bore hole has to go down about 100 metres and will cost about £3500.
Each heat pump contains an electric element which may be used automatically to help boost the temperature if & when necessary.
The Benefits
A ground source heat pump system is highly efficient and gives a performance of about 1:4 where £1 gives 4 units of energy. A fossil fuel boiler gives £1: 0.9 units as a comparison.
The heat pump requires little maintenance and lasts for about 23 years so again is favourable to gas or oil boilers.
Air source heat pumps stand outside the property and use air to generate their heat energy for your space heating. These pumps work in the same way as the ground ones but because they use air have a more varied temperature range and so are slightly less efficient.
The CoP for and an air source system is 1:3. Which is still much more economical than fossil fuel.
The Benefits
Air source heat pumps are cheaper to purchase and install.
They do not need the space for the collectors and so require no digging.
The life time expectancy is around 18-20 years and again require little maintenance.
As already stated these systems blend perfectly with under floor heating which we would strongly recommend to all of our clients because it is such a good way to space heat.
If one considers the long term, these forms of space heating are much better and much more economical than their fossil fuel competitors.
For example:
The annual cost of heating your home with oil would be around £1200 on today’s prices (50p/litre) so for 20 years about £24,000
The annual cost of heating your home with a heat pump will be about £1200 paid to you by the government!! So you will receive £24,000 back over the same time!!
Costs
The cost of installing a heat pump varies with each situation but roughly you can expect to pay £5000 for an Air source system and towards £8000 for a Ground source system.