Exploring insulation levels to enable low-temperature heating in selected buildings in two European climate zones

Abstract

This study assesses the readiness of selected building types for low-temperature heating. This is accomplished by comprehensively analyzing buildings from two perspectives: first, by determining the level of insulation required for buildings to connect to 4th Generation District Heating, and second, by identifying techno-economically viable solutions to achieve these insulation levels. The authors used OpenStudio to thoroughly examine buildings’ thermal response when the heating supply temperature is reduced from 80 to 45 °C without changing radiators. Under these conditions, the aim was to determine whether the living areas inside the buildings could be maintained at 20 °C throughout the year. Starting from a baseline with no additional insulation and old windows, the study increases the intensity of the renovation packages to assess the minimum requirements needed to maintain the desired 20 °C in the heated areas. An economic feasibility study of the solutions proposed was also conducted. A sensitivity analysis was also performed, adding insight into the impact of energy prices on renovation measures. Eight buildings, encompassing a mix of actual structures and representative archetypes derived from the TABULA project, were examined across two different European climate zones. This study found that unrenovated buildings are particularly unready for low-temperature heating and will struggle to maintain 20 °C, especially during winter. Hence, this study delivers recommendations regarding insulation and heat demand reduction measures necessary to maintain appropriate comfort. The conclusions emphasize the necessity of renovating the building stock based on geographical location to guarantee appropriate indoor comfort when reducing the supply temperature for high-temperature radiators.