Water source heat pumps

Water source heat pumps extract heat directly from the source water, possibly a lake or river, and as a result are very efficient.  They require a suitable clean water supply, which could be from a bore hole. 

The problem is, if the water supply has any contamination at all it can muck up the operation of the heat pump.  Also if the water is being ‘lifted’, i.e. pumped from a source below the level of the heat pump, then the cost of running the lifting pump has to be taken into account when looking at the overall running cost, because the COP of a water to water heat pump is very impressive. 

Generally, water source heat pumps work best if there is a large supply, such as a lake, above the level of the heat pump.  This would allow the water to be fed by gravity into the circuit through a suitable filtration system.  However, if large amounts of water are required for a big heat pump installation, then it may be necessary to obtain an extraction licence from the environment agency.  Usually, water to water heat pumps are only a suitable solution in a very small number of very specific situations.