Development and application of an indoor air quality audit to an air-conditioned building in Singapore

Good indoor air quality (IAQ) enhances occupant health, comfort and workplace productivity. This issue has become more critical in a country like Singapore that has no other natural resources except manpower. In addition, Singapore is located in the tropical region with a hot and humid climate and a large number of the buildings are served by air-conditioning and mechanical ventilation (ACMV) systems to maintain a thermally comfortable indoor environment. The provision of a thermally comfortable indoor environment for the occupants is only one aspect in achieving better indoor air quality. Chemical pollutants, dust particles and microbials are other factors that have impact on the quality of indoor air. Pollutant emissions from people, building materials, air handling units, etc. in the form of both living and dead material take place continuously in any type of buildings, i.e., residential, commercial, industrial, institutional, etc. An IAQ audit methodology developed is adopted to establish the IAQ profile of the building. In this paper, a case-study is used to demonstrate the application of the IAQ audit and evaluate its comprehensiveness and usefulness to the building owners or facility managers. This audit was conducted in the administration offices of a hospital building. The audit consists of examination of the air exchange rate, ventilation effectiveness and age of air. Thermal comfort parameters, microbial counts, dust particles and the concentrations of carbon dioxide (CO2), carbon monoxide (CO), formaldehyde (HCHO) and total volatile organic compounds (TVOC) were also monitored. In addition, a questionnaire was completed by the staff in order to provide a subjective assessment of indoor air quality.