Overhauling a sheltered residential housing development’s heating system

At the Fletchers Close sheltered residential housing development in Bromley, south-east Greater London, UK, Ground Heat overhauled the heating system to help residents remain warm and avoid expensive bills. Before our engineers installed 56 individual 3 kW ground source heat pumps, residents used gas boilers that were about 84% efficient, meaning that for every £1 spent on gas, 16p was lost through wastage. Moreover, electric hot water immersion heaters combined with cold water storage tanks put the residents at increased risk of contracting legionnaires’ disease.

Now, all apartments have individual ground source heat pumps that enable residents to control their heating and hot water, thereby reducing fuel bills and eliminating meters. Moreover, the ground temperature remains constant, so the heat pumps can be used continually throughout the year. Boreholes drilled in the area of the Fletchers Close green extract enough heat to feed the radiators. Owing to an innovative new design, the residents pay only for the energy that they use; therefore, they will have money left over from their yearly fuel allowance. The typical annual running cost for a 3 kW ground source heat pump is £180 (less than £3.50 per week) for a 60 m2 apartment. Fletchers Close apartments are smaller, which means further savings. Ground Heat is also guaranteeing residents a coefficient of performance of greater than six all year round, thanks to the custom design of the borefield.

Minimising disruption and enriching lives

Throughout the project, our work teams minimised disruption to daily life at Fletchers Close. We spoke with residents when engineers needed access to their apartments. Because of concerns about residents’ susceptibility, work was done between 09:00 and 16:00 and noise levels were kept low. Landlords and residents receive data on costs via electric pulse meters fitted to each heat pump. Training and support for the use of the new system take place as part of our aftercare programme offered to existing and future residents on an individual basis. Looking to the future, the 3 kW unit has a lifespan of 20–25 years; the main component, the compressor, should last 10 years.

Through the Technical Innovation Fund and as part of National Energy Action’s Warm Homes Campaign, the project was given £250,000 to deliver solutions not conventionally part of the current fuel poverty and retrofit energy efficiency programmes. The project also helped the local authority with meeting targets and reducing carbon emissions. Estimates show a 37% reduction in CO2 emissions compared with gas heating.