The effect of real-time context-aware feedback on occupants’ heating behaviour and thermal adaptation

Abstract

Studies have shown that building energy demand in identical dwellings could vary by a factor of three. Differences in occupant behaviour–i.e. purchase, operation and maintenance–have been implicated as a strong source of these differences. The literature suggests that feedback on energy use to building occupants–particularly real-time feedback–can be used to prompt lower operation-related energy behaviours. This is particularly true for thermal demand which, in cold countries, accounts for four times as much energy use as non-thermal demand. However, there is little evidence to support this claim. Further, there are concerns that the actions that allow occupants to lower heating energy use could negatively impact their comfort by lowering indoor temperatures or air quality below acceptable thresholds. We report results from a winter field study that used in-depth energy, environmental and motion sensing to generate real-time context-aware feedback through a smartphone application. Subjective data and clothing levels were concurrently collected through questionnaires. Our results suggest that real-time feedback could lower radiator and room temperatures without significantly affecting occupant thermal comfort. The results also show that real time feedback could contribute to an increase in occupant perceived environmental control (a key variable in the theory of adaptive thermal comfort) while prompting lower heating energy behaviours.