MARK REYNOLDS MENG
Consulting Engineer, FairHeat
mark.reynolds@fairheat.com

JAMES GALIMORE MENG, CENG, MCIBSE
Principle Engineer, FairHeat
james.gallimore@fairheat.com

JAKE ADAMSON MEng(Hons), MCIBSE
Consulting Engineer, FairHeat
jake.adamson@fairheat.com

Abstract

Retrofitting heat networks will play a major role in improving building performance and facilitating a net zero environment by 2050. A 94-dwelling social housing development based in the UK, had an operational heat network which was experiencing significant issues with overheating, resident discomfort, and poor network efficiency. The heat network consisted of 40 risers supplying heating and hot water to dwellings via radiators and hot water cylinders.

An Automatic Meter Reading (AMR) system was installed in the Energy Centre to analyse network performance and identify improvement opportunities. The data revealed the network was operating with a 74/66 °C temperature profile, and that the heat loss from exposed pipework in dwellings was providing a constant heat loss into each dwelling of 0.55 kW. The total network losses were in excess of 1000 W/dwelling, or 7,000 kWh/dwelling/annum.

An approach was taken to retrofit the entire heat network whilst minimising resident disruption. This future-proofed the heat network for allowance of a heat pump installation or low temperature district heating connection.

Quality assurance was undertaken during the design, install and commissioning of the heat network to facilitate the project’s success and hit key milestones. At present, the operating temperatures have been reduced to a 55/37 °C flow and return temperature, enabling an immediate gas consumption reduction of 44% however this is expected to increase further. Network losses have also been reduced to <80 W/dwelling.

This data driven approach to retrofitting has simultaneously improved resident comfort, reduced heat costs and enabled a straightforward connection to heat pumps or district heating.