Assessment of Indoor Environmental Quality (IEQ) in Air-Conditioned Lecture Halls of the Institutional Buildings: A Case Study for Sri Lanka

On average, a higher educational student spends 3-8 years inside an institutional building during their studies, where they tend to stay with large groups of students in confined environments for longer durations. Improper design standards and occupant control in lecture halls can result in poor Indoor Environmental Quality (IEQ), which can lead to health issues such as Sick Building Syndrome (SBS). Generally, the IEQ of institutional buildings are being overlooked in many instances with respect to commercial or residential buildings, where occupants are mostly in control of their activities and indoor environments. Therefore, to assess the variations of IEQ in lecture halls, the present study has analyzed indoor air quality, thermal comfort and acoustic comfort by considering parameters indoor CO2 level, relative humidity, and sound pressure respectively during a continuous 2-hour lecture. The study was conducted by considering University of Sri Jayewardenepura, Sri Lanka as a case study. Student responses on prevalence of SBS symptoms were collected through a questionnaire survey and an ordinal logistic regression was performed to assess whether there are co-relations between the IEQ and reported symptoms. The results of the study showed that some of the lecture halls exceeded the ASHRAE standard values indoor CO2 levels towards the end of the lecture and some lecture halls had poor acoustic comfort due to the noise of air conditioning machinery. Results from the ordinal logistic regression showed that there is a statistically significant association on prevalence of SBS symptoms such as headache, difficulties in concentration, dry throat, cough and tiredness for the lecture halls with high occupant densities. The results of this study highlight the importance of maintaining optimum design guidelines, proper occupant control and selecting the appropriate capacity of air conditioners for the lecture halls to maintain a good IEQ.