Variations in residential space heating profiles at room level: the influence of building and system characteristics

Theoretically estimated energy savings associated with better energy performance levels are rarely achieved in residential buildings. Part of this is explained by the higher indoor temperatures found at higher performance levels. Literature associates this temperature take-back with physical and behavioral causes: better insulated envelopes result in higher average indoor temperatures and inhabitants increase their comfort expectations and choose more demanding heating profiles in more efficient buildings. However, literature gives little to no proof for different heating profiles being linked to different energy performance levels. To study possible changes in heating profiles and their causes, a statistical study was conducted on survey data and energy performance assessment data on more than 575 houses and their inhabitants: old, non-insulated houses, houses with standard performance levels and high-performance houses. The study reveals significantly longer heating times in centrally heated houses compared to houses with de-centralized heating systems, but only in the bathrooms. The number of heating hours in the living proved to be more strongly associated with the presence of a low temperature heating system or heat pump than with the presence of people. The number of heating hours was not associated with the calculated net space heating and only to a small extent with other technical and socio-demographic data. These findings indicate that more demanding heating profiles do occur in higher performance houses, but mainly as a result of the type of heating system (its control and response time) and less as a result of behavioral rebound induced by the lower cost per demand ratio