Better Planet was instructed to design, supply and commission a ground source heat pump, underfloor heating and solar PV for this luxury property in Hertfordshire. As no gas from the grid was available and planning required the use of a low carbon heating system, a heat pump was the natural choice. With plenty of land available for horizontal ground loops, ground source was a more attractive alternative than air source. Despite a higher initial outlay, ground source typically beats air source financially in the long run, especially taking into account the higher tariffs from the Renewable Heat Incentive Scheme. Furthermore, ground source is slightly more efficient than air source, resulting in lower operating costs.

Underfloor heating in screed throughout. Like all projects, Better Planet designed they system to operate at consistent low temperatures, taking in to account room by room heat losses and floor coverings.

Solar PV is a great way to generate your own electricity and it is a good complement to a heat pump as the system can generate some of the electricity required to run the heating system. In this case an immersion heater controller was added to the system, diverting electricity to the immersion heater in the hot water cylinder as a means to use more electricity on site.

Project summary:

Ground Source Heat Pump

  • A Nibe F1145-12kW ground source heat pump
  • A 300 litre heat pump cylinder
  • A 200 litre buffer tank
  • Two horizontal collector loops, 300 meters each
  • Nibe Uplink allowing remote monitoring through internet
  • Estimated RHI payments: £21,903 over 7 years

Underfloor Heating

  • 16 mm underfloor pipes from LK in screed throughout
  • Manifolds from Larsson Underfloor
  • Controls from Heatmiser

Solar PV

  • 16 panels from Amerisolar with a total output of 4kWp
  • Inverter from Solis
  • Flat roof mounting system from AluGrid
  • An immersion heater controller from Apollo Gem
  • Estimated Feed in Tariffs and savings over 20 years: £16,495

Comments from the client ;

“We are still very cosy here and are still using the economy setting on the ground source heat pump.”

“I think our last quarterly electric bill was £190 and the solar panel payback was around £130. It is very exciting to be so efficient!”