Experimental investigation about thermal effect of colour on thermal sensation and comfort

According to hue-heat hypothesis, colours may have effect on temperature perception. Results of existing research are ambiguous regarding the association between colour and thermal perception. And the colours tested were quite limited. This study aims to find the possible influence of colour on thermal sensation and comfort. Experiments have been carried out to explore this effect. Sixteen Chinese subjects participated in the experiments, which contained three temperature levels and seven coloured wall conditions. Subjects' thermal sensation vote (TSV), thermal comfort vote (TCV) and colour satisfactory vote (CSV) were collected and heart rate (HR) was tested. The results show that coloured walls do have impact on thermal sensation and comfort in different air temperature conditions. Subjects' TSV was increased at warm colours and decreased at cool colours compared to neutral colours. And TCV was also affected by colours. Subjects felt that cool colours were more comfortable in warm environment, and warm colours were more comfortable in cold environment. The results of CSV showed that cool colours became more satisfactory in warm environment, while warm colours were more popular in cool environment. The variation of HR was related to temperature and colours. HR increased as temperature increased. And HR in warm colours was a little higher than that in neutral and cool colours. The changes of subjective voting and physiological parameters were consistent in supporting the thermal effect of colours. Considering this effect of colours, integrating warm or cool colours in indoor spaces can optimize thermal perception against occupants' actual thermal condition, which has positive significance for energy saving in building environment.