Grey preference analysis of indoor environmental factors using sub-indexes based on Weber/Fechner's law and predicted mean vote

Abstract

The purpose of this study was to determine the influences of environmental parameters on common health symptoms in office buildings. A grey preference analysis based on a new indoor environment quality (IEQ) index and a controlled field survey of 91 office occupants were conducted in an office building in Guangzhou, China. The new IEQ index based on Weber/Fechner’s law and predicted mean vote (PMV) was developed and validated by our survey. In the survey, the six environmental parameters (air temperature, illumination intensity, noise level, carbon dioxide, formaldehyde and PM₁₀) were measured. The subjects’ satisfaction levels and the nine health symptoms (eye dryness, lethargy, dry throat, headache, nausea, skin dryness, blocked nose, influenza-like symptom and chest tightness) were determined using questionnaires. The results show that the proposed IEQ index can preferentially predict the subjective sensations of occupants. PM₁₀ was identified as the most significant environmental parameter, followed by formaldehyde, air temperature, carbon dioxide, noise level and illumination intensity. Eye dryness and lethargy were the most significant symptoms, followed by dry throat, headache, nausea, skin dryness and chest tightness. Blocked nose and influenza-like symptom were hardly reported by subjects. The findings of this study could provide a practical guidance for IEQ management to reduce unhealthy diseases for occupants.