B055 Office IEQ benchmarks

IEQ benchmarks for air-conditioned offices of Hong Kong

Brief:

Indoor environment is designed for the good of occupants’ health and comfort. The indoor environmental quality (IEQ) in offices would be related to four environmental parameters; they are thermal comfort, indoor air quality, aural and visual comfort respectively. In this study, an office IEQ was benchmarked from an occupant’s prospect of acceptance relating to 4 basic indoor environmental factors: namely the thermal comfort, the indoor air quality, the noise level and the illumination level, with a star rating system. In particular, an IEQ index indicating occupants’ overall IEQ acceptance expressed by a multivariate logistic regression model towards the four IEQ factors was used as the benchmarking parameters. The existing office conditions reported in some survey studies in Hong Kong at certain ranges of operative temperature, carbon dioxide exposure concentration, equivalent noise level and illumination level were used as a reference to evaluate the IEQ profiles of the air-conditioned offices of Hong Kong with Monte-Carlo simulations. The results showed that, for a 5-star benchmarking system of office IEQ, the IEQ benchmark system would assigns 5 stars to the top 10% samples of the IEQ acceptance larger than 0.96, 4 stars to the next 22.5% samples of an IEQ index between 0.94 and 0.96, 3 stars to the next 35% samples of an IEQ index between 0.87 and 0.94, 2 stars to the next 22.5% samples of an index value between 0.66 and 0.87 and 1 star to the bottom 10% sample of an index value below 0.66 respectively. The proposed benchmark would serve as a quantitative assessment criterion for IEQ in an air-conditioned office environment in Hong Kong and would be a useful reference, with selected model parameters, for similar environment where an occupant’s evaluation is expected.

Further Information:

Hui PS, Wong LT, Mui KW, 2007. IEQ benchmarks for air-conditioned offices of Hong Kong, Joint Symposium 2007 on Building Services Engineering for a World Class City, 13 November, Kowloon Shangri-la Hotel, Hong Kong, pp. 13-19.