Retrofit GSHP, boreholes and UFH in Rural Norfolk

The customer was looking to install a ground source heat pump.  They live in a large, detached house in rural Norfolk and were completing a substantial extension to the existing property. They were looking to replace the existing heating system of an LPG boiler and radiators, for underfloor heating and a renewable heating system.

The main objective for changing the heating system was to have a future proofed renewable heating system for their home with the highest level of energy efficiency as possible.

The customer had done extensive research on air and ground source heat pumps and whilst an air source heat pump would have been a cheaper solution, the priority was to maximise efficiency with a ground source heat pump. This was the reason they chose to invest in boreholes for the ground source heat pump rather than ground loops, to maximise the efficiency.    The plant room was based at the rear of the garage, which housed the heat pump, buffer & hot water cylinder.

Recommended Solution

We recommended a 15kW Stiebel GSHP as this met the heat requirement capacity, without having to install 3 phase electricity as the 15kW Stiebel GSHP can run on single phase electricity.

The ground source heat pump was installed with 3 x 125 metre boreholes which were calculated for the ground source heat pump.  Underfloor heating was fitted to the ground and first floor of the property.

Carbon Reduction…the numbers

The customers main objective was to reduce carbon output from their home. A ground source heat pump was the solution which produced the least amount of carbon.

The estimated annual CO2 emissions for his existing LPG boiler system was 8,342.22 kg CO2/kWh per year.

The estimated annual CO2 emissions for the newly installed GSHP is 1062.16 kg CO2/kWh per year.

Therefore by installing the GSHP system there is a saving of 7280 kg CO2/kWh per year.

As the property was in an off gas grid area, if they had considered an oil boiler, this would have produced an estimated annual CO2 emissions of 10,315.27 kg CO2/kWh per year.

The estimated annual CO2 emissions for the newly installed GSHP is 1062.16 kg CO2/kWh per year.

Therefore by installing the GSHP system there is a saving of 9253.11 kg CO2/kWh per year compared to an oil boiler and 7280.06kg CO2/kWh compared to an LPG boiler.

The customer also has plans to add Solar PV to the system, to reduce the cost of electricity in the future and enhance his renewable system.

The opportunity to change a heating system from fossil fuels only comes round every 15 years or so, if a customer chooses to replace LPG or oil with another LPG or oil system, the opportunity for carbon reduction is lost again for another 15 years.

This installation over a 15 year period alone will save 109,200.90 kg CO2/kWh because a ground source heat pump was chosen over fossil fuels.

Find out more about ground source heat pumps and how they work.

"Without exception, the R A Brown staff were helpful when I had questions and the installers took pride in their work.  It was almost a shame to lag all of the copper piping connecting the pump and heat exchanger to the water tank and underfloor system as the pipework was so neat.  That gave me confidence that they cared about what they did" 

Mr Y, Norfolk