Combined effects of visual-acoustic-thermal comfort in campus open spaces: A pilot study in China's cold region

To investigate the combined effects of thermal, acoustic and visual comfort in open spaces, this study selected five typical spaces on a university campus with five common sounds (broadcasting music, running water & birdsong, wind (a gentle breeze) & insects, crowds, and machines) in a cold region of China. 418 volunteers were asked to complete a subjective sensory questionnaire in a randomly combined audio-visual environment while meteorological measures were taken on-site. Four primary outcomes emerged. First, broadcasting music improved individual subjective thermal comfort votes (TCV). Under the moderate heat stress (0.5 = thermal sensation vote [TSV] < 2.5), a comfortable acoustic environment helped reduce individuals' subjective TSV and increase TCV. Second, the subjective acoustic comfort vote (ACV) of broadcasting music, wind & insect sound and machine noise decreased with the increase of Universal Thermal Climate Index (UTCI); respondents perceived crowds, machines and wind & insects louder when TCV = 2 and -2. Third, under no thermal stress (-0.5 <= TSV < 0.5)/moderate heat stress (0.5 <= TSV < 2.5), TSV increased with increasing illumination intensity (LUX). Under the strong heat stress (2.5 <= TSV <= 3), there was no significant difference in TCV among subjective visual comfort vote (VCV) levels. Finally, when the LUX class was neutral/slightly bright, respondents felt darker in thermo-neutrality. Additionally, VCV and TCV were positively correlated under each LUX class.

Automated summary

This study investigates the combined effects of thermal, acoustic, and visual comfort in open spaces. The results show that broadcasting music improves individual subjective thermal comfort, and a comfortable acoustic environment helps reduce thermal sensation and increase comfort. Perception of crowds, machines, and wind & insects becomes louder under certain thermal conditions. Increasing illumination intensity also increases thermal sensation, but visual comfort has no significant effect on thermal comfort under strong heat stress.