Influence Of Window Opening Characteristics On Residence Formaldehyde Concentration Distribution

The emission and diffusion of interior pollutants can be effectively promoted by strengthening natural ventilation.Windows serve as the main component of buildngs to provide natural ventilation,its opening characteristics affected the ventilation frequency,air distribution and pollutants concentration of the residence,which is related to the health of indoor personnel.The typical new decoration residence in Hengyang city was summarized the common window-opening styles of modern residential in this thesis.Based on diffusion theory and transfer characteristics of formaldehyde,combined with field testing and simplified model verification.It compared the window-opening styles and opening angles of interior formaldehyde emission though analyzed formaldehyde rules of release,diffusion and emission by CFD numerical simulation.The main conclusions are as follows:Testing materials which commonly used in residential decoration,and the formaldehyde release was stable after about 600 min.The increase of interior formaldehyde concentration in closed residence showed a law of attenuation,and the average stable formaldehyde concentration was 7.75E-7kg/m~3.Formaldehyde concentration in bedrooms was significantly higher with small spaces and large amounts of decoration materials,however,it was lower in livingroom which were large spaces,less decoration materials,and no obstructions.Natural ventilation was a efficient method to eliminate the high concentration of formaldehyde in residential buildings.Window-opening styles affected the time of formaldehyde concentration reaching standard and stable directly.The order of formaldehyde emission rate from fast to slow:in-swinging casement window>French sliding window>bottom hinged in-swinging window>top hinged in-swinging window>half-sliding window.Through the natural ventilation process,the formaldehyde concentrations were almost equal at last no matter what kind of window-opening styles be used.In the process of natural ventilation,there were large ventilation volume,high ventilation frequency and uniform interior airflow when installed in-swinging casement window.Meanwhile,the formaldehyde concentration in rooms prone to retention was significantly lower than that of other window-opening styles.Emission rate of interior formaldehyde correlated with the window-sash opening angle positively.As opening angle reached 60°,the promoting effection on interior formaldehyde emission of increasing the opening angle was weakened.Considering both of building energy saving and interior air quality,it was advisable to open the window sashes to 60°.