Sage Journals: Discover world-class research

Abstract

The real-time indoor and outdoor radon-222 profiles on the fourth floor of a university library were measured through five consecutive days, with the Heating, Ventilating and Air Conditioning (HVAC) system operating on part load. The premises were served by a main air-handling unit (AHU-1) and a subordinate unit (AHU-2) of the HVAC system, but AHU-2 was shut down for maintenance. It required full operation of AHU-1 for 1.7h to reduce the radon concentration from the overnight peak down to the recommended action level (200Bq·m^-3). Clear characteristics of indoor radon profiles were observed, with the diurnal variations of indoor radon concentrations strongly coupled to the operation schedule of AHU-1. The specific radon production (value-Φ) of the site could be quantified from the characteristic profiles. This can be used to investigate the radon emission rate of a site, as well as to simulate the indoor radon concentrations at different ventilation rates. The value-Φ was 21.0Bqh^-1·m^-3, with a standard deviation of 0.6Bqh^-1·m^-3. Furthermore, it was found that a morning purge, by the fresh air intake fan operating for 2h before library opening hours, could not effectively remove the overnight accumulation of the pollutant.

Keywords

Specific radon production rate Heating,ventilation and air-conditioning system Ventilation Building material

Get full access to this article

View all access options for this article.

References

Pang SW , Pun WM : Territory-wide indoor radon survey 1992/93: The Hong Kong Environmental Protection Department April 1994; Report No. EP/TP/3/94.

Indoor Air Quality Management Group : Guidance Notes (GN) for the Management of Indoor Air Quality in Offices and Public Places. The Government of the Hong Kong Special Administrative Region , 2003.

Indoor Air Quality Management Group : A Guide on Indoor Air Quality Certification Scheme for Offices and Public Places (GIAQCS-OPP). The Government of the Hong Kong Special Administrative Region , 2003.

Pang SW : Interim Indoor Air Quality Guidelines for Hong Kong: The Hong Kong Environmental Protection Department 1994; Report No. EP/TP/94.

Chao YH , Tung CW , Burnett J : Influence of ventilation on indoor radon level : Build Environ 1997;32(6): 527-534 .

Chao YH , Tung CW , Chan WT , Burnett J : Determination of radon emanation and back diffusion characteristics of building materials in small chamber tests : Build Environ 1997;32(4): 355-362 .

Hafez AF , Hussein AS , Rasheed NM : A study of radon and thoron release from Egyptian building materials using polymeric nuclear track detectors : Applied Radia and Isotopes 2001;54(2): 291-298 .

Yu KN , Cheung T , Young ECM , Mui WN , Tang KK : The effects of covering materials on indoor radon concentrations in offices in Hong Kong : J Environ Radiat 2000;47: 183-188 .

Tung CW , Burnett J : Radon measurement protocol for residences with different ventilation rates : Indoor Built Environ 2004;13: 133-138 .

10.

Tung CW , Niu JL , Burnett J , Hung K : Determination of domestic air cleaner ozone emission and decay parameter by environmental chamber tests : Indoor Built Environ 2005;14: 29-37 .

Using the Real-time Radon-222 Profile to Quantify the Specific Radon Production Rate in an Air-conditioned Building

Abstract

Keywords

Get full access to this article

References