Which individual technologies are feasible to decarbonise heating in dense urban neighbourhoods?

Decarbonising the heating need of narrow terraced houses in dense urban neighbourhoods is challenging, whether it is done by using individual or collective low-carbon heating solutions. Our new study explores the potential and restrictions of individual heating systems based on heat pumps (air-to-air, air-to-water and PVT-coupled) for different insulation levels of the existing dwellings, by assessing the comfort and energy performance, financial cost, technical integration and acoustic performance.

The study was realised via a joint effort of UGent researchers from the Building Physics research group (Hannelore Scheipers, Yanaika Decorte, Eline Himpe and Arnold Janssens) and the Sustainable Thermo-Fluid Energy Systems research group (Alixe Degelin, Robin Tassenoy and Michel De Paepe), in collaboration with the City of Ghent (Dienst Milieu en Klimaat) and co-funded by the Horizon EU Mission project NEUTRALPATH.

CLick on the image below to consult the executive summary and full report (in Dutch)

Or read highlights from the study here:

• The investigated heat pump scenarios (air-to-air, air-to-water and PVT-coupled) clearly outperform the reference low-carbon scenario with direct electric heating in terms of energy performance, and lead to the lowest life cycle cost. However, since not all households can afford the higher initial investment in the heat pump system, financial support mechanisms may be needed.

• For air-source heat pumps, the placement of the outdoor unit is challenging in the studied neighbourhood (parcel width of only 4m with little or no private outdoor space). The exploration of the acoustic performance shows that especially noise pollution (for the owners and neighbours) may become a critical risk for a successful transition to individual systems in the neighbourhood. Therefore, an in-depth study of the acoustic impact of the outdoor unit of air-source heat pumps and their cumulative effect in the neighbourhood is strongly recommended.

• Before conversion to a heat pump solution, a minimal insulation recommendation is to insulate the roofs and windows of the dwelling to today's energy performance standards. However, additional insulation, especially of the outer walls, is recommended, as it further improves the energy performance, life cycle cost performance and robustness against volatile energy prices while reducing the risk of noise pollution.

• The study illustrates the importance of good sizing, and the benefits of 'undersizing' the heat pump, in terms of energy performance, costs, practical integration potential and acoustic performance. Illustration in real-life case studies, as well as training and sensitisation of heat pump installers, is recommended.