EVALUATION OF INDOOR AIR QUALITY IN A TUITION CENTRE USING SPLIT AIR-CONDITIONING SYSTEM

Abstract

In Singapore, Split Air-conditioning system has been widely used in residential premises due to its aesthetics, flexibility, acoustic properties and energy conservation. Due to its advantages, some small commercial spaces also chose to utilize such system. However, split air-conditioning system does not provide for any forms of fresh air supply from outdoor. Without a designed provision of ventilation using fresh air, there might be a potential buildup of indoor contaminants. Therefore, there might be Indoor Air Quality problems. Over the years, there has been a growing demand for Tuition Centres (TC) as parents in Singapore felt that it is no longer sufficient for their children to attend normal curriculum lessons in school. Children are the ones who are more susceptible to airborne diseases such as the recent Middle East respiratory syndrome coronavirus (MERS-CoV), Severe Acute Respiratory Syndrome (SARS), Hand, Foot and Mouth Disease (HFMD) and H1N1. It is commonly known that airborne diseases spread easier in air conditioned buildings as compared to natural ventilated buildings. Therefore, this dissertation focuses on the evaluation of the Indoor Air Quality of a Tuition Centre using the split air-conditioning system in a windowless layout. Objective measurements and subjective assessments are employed in this dissertation. The findings from this dissertation showed that the Tuition Centre did not receive a clean bill of health from the Indoor Air Quality test. The parameters that failed the test are Carbon Dioxide, Formaldehyde, Bacteria and ventilation. The highest recorded concentration levels for Carbon Dioxide, Formaldehyde and Bacteria count are 2369ppm, 0.101ppm and 1690CFU/m³ respectively. As for the ventilation, the highest computed Air Change Rate (ACH), l/s per m² floor area and l/s per person are 0.28, 0.19 and 0.25 respectively. As some of the parameters exceeded way beyond the acceptable limits, Split Air-conditioning system is not recommended to be used in TC.