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Key Info

More efficient than closed loop systems
Space heating, DHW and drinking water
Utilise the water for other uses
Borehole water supplying your heating requirements as well as your water

Heat Pumps - Open loop

FWT are specialists in the supply and installation of open loop ground source heat pumps, we have an extensive portfolio and many years experience. We install systems throughout England, the Southwest and South Wales . We undertake all the work needed to get the system up and running from the initial design to installation and commissioning ensuring you get the right system for your home or property.

FWT install Kensa heat pumps and operate under the MCS umbrella scheme to ensure you are able to claim the RHI. Kensa are the UK’s leading manufacturer and supplier of heat pumps choosing the most appropriate heat pump to meet the heating demands of your property from Kensa’s extensive range.

Open source heat pumps utilise water abstracted from a borehole or water course. The water is passed through the heat pump, which extracts some of the heat and converts it to a form that can be used in domestic hot water and heating systems. The water is then either returned to another borehole or water course or used as a private water supply. As water is a more efficient transmitter of heat than soil, open loop systems are often more efficient than closed loop systems.

Typically open loop systems are used with a borehole-based system, but springs, streams and rivers can also be used. In the case of a borehole system, the borehole pump provides a constant supply of ground water to the heat pump. The temperature of the groundwater stays fairly constant, so the heat pump can be used throughout the year.

The depth of the borehole and the quantity of water required from it depends on the size of your home and the heat load you require. Large properties will need a larger quantity of water to support the bigger heat pump, as a rough rule of thumb 2 litres/minute of water are required for every kW of heat required. Before any open source heat pump system is designed or installed a copy of detailed heat loss calculations or SAP (Standard Assessment Procedure) report will be required to establish the heat load on the property.

The benefits of open loop ground source heat pumps

  • Can provide a water supply as well as space and domestic hot water heating
  • Could lower your fuel bills, especially if you replace oil or conventional electric heating
  • Generally more efficient than closed loop systems
  • Could provide you with an income through the government’s Renewable Heat Incentive (RHI)
  • Could lower your home’s carbon emissions, depending on which fuel you are replacing
  • Does not require fuel deliveries
  • Can heat your home and provide hot water



Further information is available

Background information on open loop GSHP

Heat pump sizing open loop

Is an open loop ground source heat pump suitable for me

Main component parts of an open loop heat pump system

Open loop heat pump costs savings and earnings

Open loop heat pump efficiencies maintenance and impact

Practical things to consider before installing an open source heat pump

Step by step guide to installing an open source heat pump system

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