Simran Chaggar, Consulting Engineer at FairHeat, has developed research focused on connecting existing buildings to district heating networks. In this research, Simran explores the challenges and opportunities of adapting older buildings to operate efficiently with low-temperature heat networks, a key component of the UK’s decarbonisation strategy.
Through in-depth analysis and in-field temperature lowering testing, this research provides valuable insights into the practical steps needed to ensure that existing heating systems can maintain performance under new, lower temperature conditions. The findings offer critical guidance on building upgrades, system efficiency, and cost-effective approaches to connecting to modern heat networks.
Simran was invited to present her research at the the Smart Energy Systems Conference 2024 in Aalborg. Her research was highly recognised in the conference and awarded best presentation.
Abstract
The UK government has identified that one of the most cost-effective routes to decarbonising heat are low-temperature heat networks. The introduction of Heat Network Zoning areas in 2025 will make it mandatory for most existing buildings within those areas to connect to new low-temperature heat networks.
One of the greatest challenges is that most buildings were designed with operating temperatures greater than 82°C and small temperature differentials in the region of 10°C, whereas the district heat network (DHN) operators will likely have strict requirements when it comes to flow and return temperatures to maximise the heat network efficiency. This will incentivise both flow and return temperature lowering to increase heat pump efficiency and reduce heat losses and pump electricity consumption. This will lead to lower heating tariffs for consumers making the technology more attractive and economically viable.
FairHeat have carried out a temperature lowering test in a large commercial building over the peak heating period in the winter. The aim of the test was to reduce operating temperatures by 10°C – 15°C to identify if a low temperature heat network or heat pump solution could be a viable heat source without costly fabric and services upgrade work.
The building is heated via radiators operating at c.70°C. Boiler flow temperatures was reduced from c.75°C – 80°C to 65°C with the weather compensated space heating circuit set to a maximum of 60°C to simulate operating at flow temperatures similar to low temperature heat networks.
Live data was remotely monitored over three months of the test to identify if ambient temperatures within heated spaces were achieving the required set points.
In February 2023, the external temperature dropped below 0°C, however the occupied areas comfortably maintained 19°C – 20°C during occupied hours. The system operated well at a space heating temperature of 60°C throughout February and March.
This exercise demonstrated that reducing temperatures in existing buildings may be possible without fabric or services improvements, which would greatly reduce the cost of decarbonisation and enable the speed-up of low-carbon heating deployment.
