Assessment of Outside Air Supply for Split AC System Part B: Experiment

Indoor air quality is one of the most important aspects that determine the well-being of building occupants. Problems of indoor air quality arise in commercial buildings when there is insufficient amount of the outdoor air supply to be used to dispose of the polluted air in a room. Rooms with split air-conditioner - as it is typically installed in Indonesia - do not have mechanical ventilation system, so that the outside air exchange occurs only through the process of infiltration. The proponents of this sub-standard cooling system design claim that the infiltration rate is sufficient to achieve the ventilation requirement as required by the building regulation. However, there is no proof to substantiate that claim. This study aims to quantify the amount of outside air introduced into the room through the process of infiltration. This study uses the tracer-gas decay method with the carbon dioxide (CO2) as the tracer gas. The infiltration rate in eight different rooms in a university was measured. This study found that the infiltration process cannot provide sufficient outside air supply as required by the building regulation.