Ground Source Heat Pump

In the autumn of 2005 we installed a ground source heat pump to provide all the under floor heating and hot water for River Barn and Lois' cottage. Again this is an expensive piece of kit! We were lucky and were awarded a grant towards the large capital outlay.

A heat pump, for those who don't know, works like a back to front fridge. Instead of extracting heat from within a fridge to cool down the interior, a heatpump extracts the heat from either the outside air or the ground and transfers it to, in our case, lots of hot water. The hot water is stored in a very large insulated cylinder. Underground, water is pumped around the 800 meters of pipes that we laid over 1.2m deep in the field. As the water passes back through the heat pump, it is cooled and the heat is extracted. The water contains anti freeze to stop it from literally freezing. The icy cold water is then pumped the 800m through the ground again where it slowly warms back up to the ground temperature. The electricity used to extract the heat produces 3 to 4 kW of heat for every 1 kW of electricity used.

The heat pump is less efficient at heating water to high temperatures. This is why a heat pump is so effective used in combination with underfloor heating. Hot water used for UFH runs at a lower temperature than water used for traditional radiators. Underfloor heating is also great because the heat is under your feet and the stone floor conducts the heat well into the rooms. It is a very much pleasanter heat to live with than radiant heat produced conventional radiators.

If you are thinking of reducing your carbon emissions by installing a ground source heat pump with under floor heating, do ask for more information. Whilst staying here, guests are very welcome to look at the heat pump and heat store at Treworgey.