Abstract
Indoor negative pressure by simultaneous use of exhaust fans causes such problems as increase of power needed for opening entrance door. In order to evaluate air-flow rate deterioration of ventilating openings in continuous ventilation, field measurement was conducted in apartment buildings for three months. The result showed that air-flow rate of ventilation filters decreased 3-8% during the period. Also, their dust removal performance remained throughout the period, and its air-flow rate was estimated to decrease around 5-15% in half year.
