AIR QUALITY IN THE NUS INTERNAL SHUTTLE BUS

Abstract

In NUS, the internal shuttle service is the main mode of transport that brings 50,000 commuters to the various destinations in or around the campus. Poor in-bus indoor air quality (IAQ) is likely to impact the health of not only the bus drivers, who are exposed to the poor IAQ for a long period of time, but also the large number of commuters who utilize the internal shuttle service. The objective of this study is to measure the IAQ and thermal comfort parameters on randomly selected NUS shuttlebuses and to compare the results based on the periods (Peak and Off-peak) and bus types (New and Old). Two hypotheses are established. H1 states that the IAQ on the shuttlebuses is worse in peak periods than in off-peak periods while H2 states that the IAQ in the New bus will be better than the Old bus. Objective and subjective assessments are carried out to investigate the IAQ in the buses. The objective assessment includes the physical measurement of selected chemical and thermal comfort parameters recommended in SS554:2009, while the subjective assessment includes interviews with bus drivers and a survey conducted on commuters. The results showed that the off-peak periods performed better than the peak period, in terms of both thermal comfort and IAQ, proving that that H1 is valid. On the other hand, H2 is proven to be invalid as the results illustrated that both the IAQ and thermal comfort is better in the Old bus.