Effects of light and ambient temperature on visual and thermal appraisals

More than one third of a buildings’ energy consumption is designated for heating and cooling. Therefore, allowing more variations in the indoor temperature provides an energy saving potential. Additionally, these variations are expected to have beneficial health effects on the building occupants. To compensate for potential discomfort amongst them due to these temperature variations, LED lighting may be used as light could influence thermal responses via cortical and sub-cortical brain regions. Two laboratory studies were performed to examine how different light conditions can influence both visual and thermal appraisals. Temperature was manipulated between these studies: the first was in a thermoneutral environment (21 °C) whereas the latter was performed in a mild cold environment (17 °C). In contrast, light was manipulated within the studies. Participants came to the laboratory on multiple days, during which they were exposed to different light conditions in terms of both correlated colour temperature and intensity. Participants evaluated their visual and thermal experiences repeatedly throughout the session. We can conclude that visual and thermal comfort are closely related. These findings could be applied in office environments to save energy by controlling the temperature less strictly and compensating potential thermal discomfort with visually comfortable light settings.
Keywords: Cross-modal effects, thermal appraisals, visual appraisals, temperature, light