Nudging and usage of thermal comfort-related systems

The effect of nudging on the usage of an energy-consuming device associated with human indoor thermal comfort is investigated together with the corresponding effect on occupant subjective thermal comfort. Thirty-six subjects participated in an experiment conducted in an environmental room controlled to maintain a stable warm condition (operative temperature: 29.5°C; corresponding PMV: 1.44). Each subject had full control over a small, individual desk fan, and feedback messaging (the ‘nudge’) was delivered via laptop computers. Real-time usage status of desk fans was monitored, and subjects completed questionnaires before and after their test session, in addition to within-session subjective thermal evaluations. For the sample tested, feedback messaging was observed to nudge occupants to reduce usage of the device (desk fan) in the warm environment and to tolerate accompanying thermal discomfort, though preference to be cooler increased for some. Whilst this finding may eventually lead to future application for supporting changes to HVAC system operation and setpoints that align with adaptive comfort ranges, it is essential that further, more comprehensive, research is undertaken to re-confirm this finding and to explore other thermal situations in which it might apply. Moreover, implications for human health and well-being should be investigated prior to implementation in practice.