INVESTIGATING THE EFFECT OF VENTILATION RATE ON CO₂ CONCENTRATION DISTRIBUTION IN OFFICES

ABSTRACT This paper enquires on the linkages between the rates of ventilation and indoor carbon dioxide (CO₂) concentration in different environments that are offices. The objective was to determine the effect of differences with ventilation performance, air change frequency, occupancy rate and size of room on indoor environmental quality. Measurements in the field were taken in ten office rooms on one university campus, and also values of CO₂ were determined, as well as the data on ventilation frequencies, the volume of the room, and the number of occupants. The findings showed that there was a definite negative correlation among the rate of ventilation and indoor CO₂ level. The higher the ventilation rates and the amount of air changes per hour (ACH), the lower the CO₂ levels corresponded to the evident improvement of the air quality and compliance with the international standards and requirements such as ASHRAE 62.1 regarding the work of office buildings, WHO, and U.S. EPA guidelines. In contrast, lowly ventilated rooms particularly those with high occupancy density indicated high CO₂ concentrations that are most of the times above the recommended concentration. It is concluded by the study that it is very necessary to maintain a proper and healthy ventilation of good quality in an indoor atmosphere particularly in the case of shared offices and such mansions. Solutions include use of demand-controlled ventilation, frequent HVAC servicing, monitoring of real-time occupancy, efficient air quality and comfort within buildings.