B039 Office IAQ screening

Screening for workplace indoor air quality

Brief:

In Hong Kong, the Environmental Protection Department (HKEPD) launched an Indoor Air Quality (IAQ) certification scheme to grade ‘Excellent’ or ‘Good’ IAQ in workplaces by measuring the levels of twelve common indoor environmental parameters. However, assessment of all of these parameters in a large space is costly in terms of measurement time and effort. And in some cases, difficulties in handling the equipment and measurement data were reported. Assuming the twelve parameters are independent, this study investigates the feasibility of a simple screening test that can identify unacceptable office IAQ by the measurement of a few ‘dominant’ contributors only. In particular, recent assessment results of the twelve parameters according to the scheme from 422 offices were reviewed and used to identify the dominant contributors of unsatisfactory IAQ for workplaces in Hong Kong. Comparatively, measurements results of the screening test showed that 96% (94% to 98% for 95% confidence interval) of the ‘unacceptable’ offices (414 sample) could be identified from the measurements of TVOC, RSP and HCHO against the ‘Excellent’ IAQ level, while 93% (90% to 97% for 95% confidence interval) of them (201 samples) could be identified from the measurements of TVOC, ABC, RH, HCHO and O₃ against the ‘Good’ level. Applications of the screening test to some other air-conditioned offices in Hong Kong were also demonstrated. The results showed that the failure probability of the proposed screening test in identifying unacceptable office IAQ was below 3%.

Further information:

Hui PS, Wong LT, Mui KW, 2006. Screening for workplace indoor air quality, Joint Symposium 2006 – Efficient Built Environment for Tomorrow, 14 November, Kowloon Shangri-la Hotel, Hong Kong, pp. 95-101.