IAQ OF A RESIDENTIAL BUILDING IN SINGAPORE: NV VERSUS AIR-CONDITIONED BEDROOM IN A HDB FLAT

Abstract

The coronavirus disease (COVID-19) has thrown the world into disarray when it first emerged in 2019. To combat the spread of the virus, governments worldwide have implemented social distancing measures and instructed businesses to ensure that all employees who are able to work from home do so. The sudden increased amount of time spent indoors has shone a light on the importance of Indoor Air Quality (IAQ), now that people are spending their work and play hours in the same environment. The same has happened in Singapore. Being a country that has both a hot and humid climate, most of Singapore’s residential buildings have some sort of air-conditioning system to cool the space for indoor thermal comfort. The rest rely on a mix of natural ventilation and mechanical ventilation such as fans to cool down the interior of the building. The aim of this study is thus to compare the IAQ in a naturally ventilated and air-conditioned bedroom in Singapore. In this study, objective measurements were carried out in the same bedroom at different timings under different conditions. The objective assessment includes the measurement of 7 IAQ parameters, namely, temperature, relative humidity (RH), air velocity, carbon dioxide (CO2), carbon monoxide (CO), Total Volatile Organic Compounds (TVOCs) and Particulate Matter (PM). The results should serve to help Singaporeans working at home understand the pros and cons of working in an air-conditioned environment compared to using mechanical ventilation to complement natural ventilation. The analysis shows that the IAQ levels under natural ventilation and air-conditioned conditions are generally similar, with thermal comfort parameters favouring air-conditioning with a lower temperature and relative humidity. However, the higher level of accumulated carbon dioxide in air-conditioned environments can be harmful to occupant health in the long run, and is one of the major downsides to working with air-conditioning. In conclusion, both environments have their own merits when it comes to the different IAQ parameters. However, an air-conditioned environment can provide a more thermally comfortable environment than a naturally ventilated one, as long as the IAQ parameters, with focus on carbon dioxide levels, are kept within the SS554:2016 recommended limit.