Boreholes for Heat Pumps
Different options are available for the installation of the pipework or Ground Loop which collects the stored solar heat used by heat pumps. These include Slinky and Straight Ground Loops where the pipes are laid in trenches beneath the ground, or alternatively when space is at a premium, there is the added option of using boreholes.
Boreholes for Heat Pumps - Specification and location
Boreholes for heat pumps will have been designed and specified to provide sufficient energy collection from the ground to allow the ground source heat pump to operate efficiently. Ice Energy ensures that the borehole is always installed according to the manufacturers design and we only work with drilling companies who are affiliated to the British Drilling Association providing you with complete confidence that the drilling process is being conducted by true professionals.
The depth of the borehole will be dependent on several variables including the heat load of the property and the geology of the local ground both of which will have been established by Ice Energy during the project specification and site survey. The location of boreholes for heat pumps is always site specific and will also have been determined during our in-depth planning process.
Boreholes for Heat Pumps - Drilling
Ice Energy operates several rigs of varying sizes and can accommodate the drilling of boreholes for heat pumps from the smallest gardens right up to the biggest building sites. We use a conventional rotary system, where the rig rotates drilling rods into the ground, cutting their way in as they go. This method is relatively clean, although there will be some spoil and a little water discharged, though this will be tidied up by our on-site teams. Using this method we can expect to drill between 50 and 60 metres of hole per day.
How many holes, how deep and how big?
The specification of the boreholes for heat pumps is calculated using software that takes into consideration the size of the heat pump, the geology of the ground and the heat losses of the house or building. Boreholes will usually be between 60 and 120 metres deep and may consist of any array of anything between 1 and 12 boreholes depending on the project size. A standard borehole is approximately 120 - 150mm in diameter.
What goes in the borehole?
Once the drilling of boreholes for heat Pumps is completed to depth, the borehole loop is inserted into the hole. This loop consists of a pair of plastic pipes that are joined together at the bottom by a 'U' bend. This bend is joined by a method called electro-fusion welding and is manufactured and tested in the factory. Once the loop has been lowered into the hole it must be filled with water and pressure tested.
Backfilling the boreholes
As soon as the borehole loop has passed the pressure test, the hole is backfilled. It is important that the backfill material is the correct type and that it fills the hole completely so our experienced pump in a natural clay compound which is mixed with water into the bottom of the hole and this then solidifies over a long period of time. When finished, all that remains will be the tails of the pipe protruding approximately 500mm from the ground. The drillers will attach end taps to these pipes to protect them. This then leaves the boreholes for heat pumps ready for connection to the manifold by others.
Ice Energy provides a fully project managed service to meet all your project requirements ensuring the work is professionally undertaken and completed to our exacting standards.