Passive and active personalized heating systems at a lower indoor ambient temperature

Abstract

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. 1. Introduction In Flanders, residential buildings represent 17% of the total energy consumption [1] and 50% to 75% of the energy consumption is used for space heating [2]. Thus, reducing energy use for heating can have a significant impact on the total energy consumption. Nowadays, energy savings are mainly driven by high insulation standards, airtightness requirements, energy-efficient appliances and energy-efficient all-air heating systems. However, these measures cause high material consumption and cannot always be executed correctly in older buildings. Furthermore, dwellings are typically heated by single-zone central heating systems, controlled by a central thermostat [3], whereas analysis of effective spatial use shows that residents do not use all rooms completely nor at the same time [4, 5]. Adapting the heating system to the effective spatial use by only heating places where residents actually reside, could lead to more sufficient heating. Additionally, it could be a relatively simple and temporary low-cost energy saving alternative for the traditional cost-and material-intensive renovation. Studies [6-8] already showed that human subjects can be comfortable at temperatures below current standards by making use of personalized heating. However, these studies are mostly focusing on office environments where