Indoor Formaldehyde Concentration Increase and Decay Pattern in a Real Residential Unit

摘要

Formaldehyde is commonly observed in indoor air, and it is proved that it has significant effect on human health. Natural ventilation is an effective way for pollutant removal. One of the most directly usage way is to open and close the window, but the indoor pollutant concentration decreases with window open. The decayed pattern under different window opening angles has not been studied well. In this article, the formaldehyde concentration increase pattern when external windows and doors were closed and the decay patterns under different window opening angles were studied. The increasing tendency is fast at the beginning 2 h and then slower for the following 2 h. The concentration decay pattern under different window open angles was different, and the larger the window open angle, the faster is the decay of the indoor concentration. Indoor formaldehyde concentration can be removed in several minutes if we open the window at 90°. The timescale of formaldehyde concentration increase pattern is much longer than the decay pattern which takes hours. It implies that to control indoor formaldehyde concentration, we should open the window more frequently other than keeping it open and close for a long time.