Building renovation level requirements for a 5th Generation District Heating and Cooling Network

In Europe, the heating and cooling demand accounts for more than 60% of the final energy use in the residential sector. District Heating and Cooling (DHC) networks, in particular the 5th Generation (5GDHC), represent a valuable solution for the reduction of primary energy use and both global and local emissions, thanks to their low supply temperature (neutral temperatures allow easy energy exchange and are boosted by local heat pumps) and increased share of residual and renewable energy sources (R2ES).

This study investigates the influence of building renovation levels on the 5GDHC network’s performance. Renovation strategies for existing buildings aim for energy efficiency and thermal comfort, and need to account for the low-temperature of 5GDHC networks. Four different renovation level scenarios with different building envelope UA-values and mechanical ventilation types in a virtual 5GDHC network are analysed and compared, using physics-based (white-box) Optimal Control (OC) as system integrator.

This analysis shows that well-renovated buildings achieve low energy use and good thermal comfort, particularly during the cold season. Conversely, a future-proof thermal system controlled by a future-proof system integrator can benefit from mixed renovation levels within a district in the summer period.