Feedback messaging, thermal comfort and usage of office-based personal comfort systems

Psychological processes are involved in human thermal comfort evaluation, and play a role in people's judgement of their thermal environment. Could these processes be beneficially managed in some way? This paper reports what is believed to be the first investigation of whether messaging, in the form of energy feedback and social normative information, can affect human subjective thermal comfort-related evaluations. Work was conducted in a controlled environmental room, the context being that of a multi-occupant office with messaging being delivered to individuals via a computer screen on each desk. Investigations were conducted for a range of warm office conditions (24.5 °C, 27 °C, 29.5 °C, as might be encountered in summertime). Experimental sessions of two hours’ duration were undertaken for: no messaging; messaging appearing at the second hour; messaging present at first hour then removed at second hour. A total of 62 subjects (23 female and 39 male) took part, with all (except one) of the thermal conditions that involved messaging being experienced by 9 participants. The appearance of energy feedback and social normative messaging was found to have a statistically-significant effect on reported thermal sensations, reported thermal comfort and reported intended desk fan usage, these being observed at the higher end of the temperature range, but had no effect on other subjective evaluations. Presence, then removal, of messaging showed no significant effects, as did an effective ‘control group’ comparison. Whilst effects were observed on certain subjective thermal evaluations at the higher temperatures, these were at the 95% confidence level, and it is recommended that a larger scale study be undertaken to confirm, or otherwise, these observations. The study offers a method that can be followed for future investigations under controlled conditions, and serves to design further, larger-scale, experiments, to investigate actual usage of personal comfort systems and the role of messaging in this context. Implications of any ‘intervention-type’ influences (of which ‘messaging’ could be an example) on subjective evaluations, if confirmed, may open a new way to help manage human thermal comfort and energy use in offices or similar environments, but this will require further careful consideration, particularly from the perspective of human health and well-being, prior to any deployment in practice.