Single and Multiple Zone Methods to Calculate Air Change Rate in Apartments

Indoor air quality is significantly associated with ventilation. In China, natural ventilation system is the norm in residential buildings. In China this means only leakage and opening of windows, doors. The present study developed a practical and feasible method to measure air change rate in residential buildings. The air change rates in residential buildings were calculated by using CO2 produced by occupants as tracer gas. Portable CO2 monitors were located in representative rooms and measured CO2 concentration for 24 hours continuously. Single zone model and multiple zone model were developed to calculate air change rates. 266 dwellings were measured. The air change rates in 40% dwellings were calculated as single zone since the CO2 concentration differences in representative rooms were less than 10%.