The Effect of ventilation on sick building syndrome

Abstract

It is well known that adverse health conditions could develop due to outdoor air pollutants, such as, CO2, CO, SO2, NO2, PM (particulate matter), VOC (Volatile Organic Compounds), when people are outdoors, while travelling or working. Since most of the people spend 80-90% of their time indoors, at home or place of work, the presence of these air pollutants could adversely their health while indoors, as well. Hence, minimizing the presence of air pollutants, by taking appropriate measures, such as, ventilation and air conditioning are important to ensure that a healthy atmosphere prevails indoors. In a work place, where a large number of people work within a confined space, CO2 produced due to human respiration gets accumulated in the air, unless there is good ventilation. Long exposure to higher CO2 concentrations can cause human discomfort and ill health. The CO2 concentration, if measured, can be a direct indication of the efficiency of the ventilation system of the building. This paper presents a detailed study on how building planning aspects can affect the indoor environment of a building. The main factor considered was the CO 2 concentration in relation to the ventilation design of the building. In the study, CO2 concentration was measured and related to the ventilation design of the space in both free running and air conditioned buildings. The main findings of the study are as follows. a) Planning aspects of building were found to be very important in minimizing the bad effects of air pollutants. b) Provision of openings, based on external wind directions and orientation of the building were important, to dilute and remove high internal air pollutant concentrations by natural air currents. c) Provision of openings in excess of what is provided in the building regulations was found to improve the ventilation system in a free running building. d) The efficient operation of the natural ventilation system was as important as the ventilation design.