Outdoor thermal comfort study in a sub-tropical climate: a longitudinal study based in Hong Kong

• Published in: International journal of biometeorology Vol. 56; no. 1; pp. 43 - 56
• Main Authors: Cheng, Vicky, Ng, Edward, Chan, Cecilia, Givoni, Baruch
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer-Verlag 01.01.2012; Springer Nature B.V
• Subjects: Absolute humidity; Adult; Air temperature; Animal Physiology; Biological and Medical Physics; Biophysics; China; Cities; Climate; Climate change; Climatic conditions; climatic factors; Earth and Environmental Science; Environment; Environmental conditions; Environmental Health; Female; Hong Kong; Humans; Humidity; Longitudinal Studies; Male; Meteorology; Middle Aged; Original Paper; Outdoors; Plant Physiology; Predicted Mean Vote index; Radiant flux density; Relative humidity; Sensation; Solar radiation; Subtropical climates; subtropics; summer; Sunlight; Surveys; Temperature; Thermal comfort; Thermosensing; Tropical Climate; Tropical climates; Wind; Wind effects; Wind speed; Young Adult; Hong Kong China; China; Hong Kong; China, People's Rep., Hong Kong; Outdoor comfort; Wind; Thermal comfort; Longitudinal; Hong Kong
• ISSN: 0020-7128; 1432-1254; 1432-1254
• DOI: 10.1007/s00484-010-0396-z

This paper presents the findings of an outdoor thermal comfort study conducted in Hong Kong using longitudinal experiments—an alternative approach to conventional transverse surveys. In a longitudinal experiment, the thermal sensations of a relatively small number of subjects over different environmental conditions are followed and evaluated. This allows an exploration of the effects of changing climatic conditions on thermal sensation, and thus can provide information that is not possible to acquire through the conventional transverse survey. The paper addresses the effects of changing wind and solar radiation conditions on thermal sensation. It examines the use of predicted mean vote (PMV) in the outdoor context and illustrates the use of an alternative thermal index—physiological equivalent temperature (PET). The paper supports the conventional assumption that thermal neutrality corresponds to thermal comfort. Finally, predictive formulas for estimating outdoor thermal sensation are presented as functions of air temperature, wind speed, solar radiation intensity and absolute humidity. According to the formulas, for a person in light clothing sitting under shade on a typical summer day in Hong Kong where the air temperature is about 28°C and relative humidity about 80%, a wind speed of about 1.6 m/s is needed to achieve neutral thermal sensation.