Indoor and Built Environment

 

Advanced Search

Journal Navigation

Journal Home

Subscriptions

Archive

Contact Us

Table of Contents

Click here to register and gain free access

Sign In to gain access to subscriptions and/or personal tools.
This Article
Right arrow Full Text (PDF)
Right arrow References
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in ISI Web of Science
Right arrow Alert me to new issues of the journal
Right arrow Add to Saved Citations
Right arrow Download to citation manager
Right arrowRequest Permissions
Right arrow Request Reprints
Right arrow Add to My Marked Citations
Citing Articles
Right arrow Citing Articles via ISI Web of Science (1)
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Hui, P.S.
Right arrow Articles by Law, K.Y.
Right arrow Search for Related Content
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us   Add to Digg   Add to Reddit   Add to Technorati  
What's this?
Indoor and Built Environment, Vol. 16, No. 2, 130-138 (2007)
DOI: 10.1177/1420326X06076259

Survey of Unsatisfactory Levels of Airborne Bacteria in Air-conditioned Offices

P.S. Hui

Department of Building Services Engineering, The Hong Kong Polytechnic University, Hong Kong, People's Republic of China

L.T. Wong

Department of Building Services Engineering, The Hong Kong Polytechnic University, Hong Kong, People's Republic of China

K.W. Mui

Department of Building Services Engineering, The Hong Kong Polytechnic University, Hong Kong, People's Republic of China

K.Y. Law

Acron Environmental Technology Limited, Sheung Wan, Hong Kong, People's Republic of China

Those involved in property management are under pressure to alleviate the risk of disease spread through buildings, especially via the Heating, ventilating and air-conditioning (HVAC) system. To aid this, the level of indoor bacteria can be used as a referent to identify the performance of the HVAC system. Epistemic assessment of an AC office requires prior knowledge of the probable failure rate of offices in a region, which may be obtained by extensive measurements. This study proposes a statistical model to obtain a rapid estimation of the office probable failure rate over a region, that is, that fraction of offices with an average bacteria level above certain action levels. The model was based on transformation of small sample data to a geometric distribution using two analytical unbiased estimators: the weighted average and corrected sample variance of bacteria levels. These estimators could improve the accuracy of the estimates due to uncertainties of small sample sizes. Model parameters were determined from a dataset of levels in 290 Hong Kong offices (average 703 cfu m— 3 and 95% range 204—2418 cfu m— 3), using Monte Carlo simulations. The model was validated with another district survey of 109 offices in nine major Hong Kong commercial districts (average indoor bacteria level 297 cfu m—3 and 95% range was 69—1266 cfu m—3). The observed office failure rate of each district was compared with the corresponding model estimate and consistent results were found.

Key Words: Indoor air quality • Indoor environment • Bacteria measurement • Office • Subtropical climates • Statistical model


Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us   Add to Digg Digg   Add to Reddit Reddit   Add to Technorati Technorati    What's this?