A THERMAL COMFORT STUDY IN SCHOOL OF DESIGN AND ENVIRONMENT (NUS)

Abstract

School of Design and Environment is currently experiencing high utility expenditure. On average, $61,000 is spent monthly on utility expenditure. Investigations were conducted to find out the cause of the high utility expenditure and also on the level of thermal performance of air conditioned areas of lecture theatres, seminar rooms, department offices and the Information Resource Centre (IRC). These investigations were conducted with means of instrumentation and survey questionnaires.

It was analysed that high utility consumption was caused by improper scheduling of air conditioning system. It was found out that air conditioning is provided during periods where occupancy rate is zero. For instance, during semester term, air conditioning is constantly been provided for lecture theatres and seminar rooms after 6.00pm when the level of teaching activities is very low.

Observations had been made on the thermal comfort performance in these locations. It was noted that the level of thermal sensation defined by the occupants in lecture theatres and IRC is considerably too cold. Out of three of the lecture theatres experimented, two of which fall below the targeted standard as specified. Moreover, the air movement in all locations was found to be very low, some of which are providing a reading of 0.01 to 0.02 m/s. Observations had also been made on the relationship between thermal comfort and subjects with different metabolic rates. Due to the type of activity performed, it was noted that there is no difference between those subjects with different metabolism. The amount of metabolic heat produced by subjects is low. Thus, the level of thermal comfort did not vary much.

Recommendations had been made to this research. An expert walk-through was necessary to check whether there are the other areas that are facing similar problems of cold temperature and low air movement. Rescheduling of the air conditioning system is another consideration as this could help reduce the wastage of energy. Shifting of smaller lecture groups to a seminar room or executive room is also recommended. Finally, readjustment of temperature and air movement is suggested to help increase the level of thermal comfort within the air conditioned area and also to reduce utility expenditure.