53% reduction in network heat losses

Saving more than 1,700 kWh per annum across the site

 Residents’ heat consumption reduced by 20-30%, saving £140 per household per year

''FairHeat's strength is its extensive knowledge and experience in the sector, the team was able to gather valuable performance data from our network and put in place practical measures to improve its performance. Over recent years an increasing number of social housing providers have become heat suppliers, taking responsibility for heating their tenants' homes through heat networks. This presents a significant challenge for providers. They are not only responsible for the metering and billing on site, but the upkeep and maintenance, while also having to ensure efficiency. FairHeat’s specialist knowledge can only make it less daunting for social landlords to build and manage networks, saving them significant amounts of money."

Patrick Flynn

Gas Contracts Manager at Network Homes


Network Homes is a charitable housing association providing over 20,000 affordable homes for more than 38,000 people across London and Hertfordshire. They have been leading the transformation of the Stockwell Park Estate near Brixton since 2005. Network Homes have invested more than £100 million so far on refurbishment, new-build and community enhancement and a further £75 million is earmarked for completion of the programme in 2018.

Network Homes began working with FairHeat in 2015 as part of a pilot project funded by the Department of Energy and Climate Change (DECC). FairHeat worked with the provider on a heat network in Stockwell Park, serving 91 of the homes on the estate. The project offered Network Homes the chance to evaluate the energy efficiency of its heat network and look at ways to improve it.


“Ideally, it is better for us to engage with heat networks at the design or acceptance stage, so we can spot and rectify issues early,” said Gareth Jones.

The challenges at Stockwell Park were significant. Data collected by the monitoring system installed on the network uncovered network losses of 3,35DkWh per dwelling per year (Roughly equivalent to the total annual useful heat requirement), while Fairheat also diagnosed issues with the network’s Heat Interface Units (HIUs).

HIUs act as the interface between the heat network and the heating and hot water systems of the individual apartments. In this case, the components had not been commissioned properly and were performing poorly, with resulting high return temperatures.

As well as issues with key components, the data and site investigations also found missing insulation on pipework into dwellings. Without insulation, these pipes were acting like radiators, constantly losing heat to the hallways and communal spaces.

FairHeat Solution

For heat networks that have been operational for some time, FairHeat works to deliver continuous network improvements. In this project FairHeat carried out a full performance monitoring service.

FairHeat’s Managing Director Gareth Jones explains the process:

“Initially the Stockwell Park heat network was retrofitted with monitoring systems in each property and the plant room. These were used to measure gas use in the plant room, the power consumed by pumps, the flow and return temperatures throughout the network, and the heat being consumed by each household. This information was then used to visualise heat network performance, allowing us to diagnose the cause and location of any inefficiencies and recommend improvement measures.”


“I was very pleased with the accuracy of the results generated. The initial data indicated that all the HIUs tested were underperforming, and were under insulated or locked the correct valves, and there was a lack of insulation across the network,” said Patrick Flynn.

The analytics and diagnostics delivered by systems on the network provided the information required for Fairheat to implement improvements to the Stockwell Park network. These changes resulted in:

53% reduction in network heat losses

47% reduction in terminal run temperatures vs. ambient for dwellings with interventions

60% reduction in terminal run losses for dwellings with interventions, saving more than 1,700 kWh per annum across the site

Together these have resulted in significant savings for residents. Over the course of the project, residents’ heat consumption reduced by 20-30%, saving £140 per household per year. Patrick Flynn concludes: “FairHeat’s specialist knowledge can only make it less daunting for social landlords to build and manage networks, saving them significant amounts of money.”


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