Influence of Comfort Expectations on Building Energy Need

Abstract

Increase thermal comfort is considered as one of the main benefits of a deep renovation right after energy saving. However, an increase in thermal comfort could be seen as a behavioural change caused by the energy efficiency improvement that reduces expected energy saving: the so-called rebound effect.This paper shows how building energy need is correlated to comfort category, defined in EN 15251. The study is conducted via dynamic simulations performed by TRNSYS 17 software using 3D multi-zone models. Models are tailored on occupant behaviour and driven by thermal comfort constraints. Calculations of energy need for space heating and space cooling is done both before and after a deep renovation. The effect of building and user characteristics is evaluated too. Users are differentiated by number of persons and occupancy schedule.The relation between thermal comfort, set-point temperature and energy need is investigated, focusing attention on changes that occur after the building has been thermally insulated. Computational results are critically discussed and compared with an empirical study on building renovation that includes a survey on thermal comfort perception and user behaviour. Finally, rebound effect is discussed and its magnitude is evaluated.