Despite the efforts to improve the energy efficiency of buildings, the actual energy consumption decreased much less than expected in recent years. Therefore, energy sufficiency is gaining attention as a complementary approach to energy efficiency. It aims to reduce the actual energy consumption of buildings by providing thermal comfort to residents in a sufficient way. This demands for alternative heating practices, such as the application of personal heating systems. Although a review of past studies shows that, in office buildings, thermal comfort can be provided with less energy by using personal heating systems, the application in a residential context is much less explored. Our hypothesis is that an innovative, energy-sufficient personal heating practice also has potential to reduce the overall energy consumption in dwellings. Therefore, this paper presents the results of a one-week case study on personal heating as an energy-sufficient heating practice in three dwellings. During the case study, the ambient temperature was reduced to 18 °C, and residents were allowed to use active and passive personal heating systems to make themselves as comfortable as possible. They were also asked to evaluate their thermal sensation and thermal comfort. The results show that, despite a lower indoor temperature, residents are able to achieve thermal comfort by using personal heating at the locations where they effectively reside. Additionally, a significant energy saving potential was found. The case study proved our hypothesis, leading to the conclusion that an innovative, sufficient personal heating practice in dwellings can be a supplementary step to reduce the energy consumption to meet the global challenges.

Dwellings in Belgium are comparatively larger than dwellings in other European countries. Moreover, their size is not always in line with the actual occupancy rate. Nowadays, most of these dwellings are heated by a single-zone, mostly convection-based heating system which heats all rooms simultaneously and completely. However, analysis of the effective spatial use shows that residents only use specific spots within a room at different times of the day, thus current heating systems do not correspond to the actual use of space. Nowadays, manufacturers focus mainly on increasing the efficiency of heating systems, while increasing the sufficiency of heating, i.e. using heat only at places where people are staying, can save a large amount of energy. In recent years, personalized acclimatizing systems in office buildings are well researched, especially for comfort improvement. However, less research is focussing on the opportunities of personalized heating as an energy saving option in residential buildings. Therefore, an experiment was performed on passive and active personalized heating systems, tested with 16 subjects, in a simulated living room at an ambient temperature of 18°C. The results of this experiment show that by making use of passive as well as active elements, people can feel comfortable at an indoor temperature lower than the commonly prescribed temperature of 21°C.