Study on Suppression of Dew Condensation for lnsulation made of Cellulose Fiber

两个相同大小的实验房屋（楼层：7 m^2）填充纤维素纤维作为绝缘材料。一个房子（A房子）在墙的外侧有通风空间，另一个房子（B房子）没有通风空间。从7点到22点，室温和相对湿度被调节为22 ℃和80%。分别在2周和4周的时间内，每隔1小时对每栋房屋的40个点进行温度、相对湿度的测量。实验结果表明：1）两户住宅之间的温度没有明显差异; 2）A户住宅的保温层两侧存在绝对湿度梯度。绝热层表面的湿度高于内部。相反，在B房屋中没有观察到湿度梯度。3）B房屋的外墙外保温层的含水量比A房屋的高（约1.2倍）。在实验室中估算了纤维素纤维的蒸汽渗透率。保持绝缘层两侧的绝对湿度恒定，测量了绝缘过程中的水汽输送量，纤维素纤维的水汽输送量取决于两侧湿度的差异，而玻璃纤维的水汽输送量则不相同。纤维素纤维的蒸汽渗透率估计为1.9，与木质纤维板的蒸汽渗透率接近。纤维素纤维对水分的吸附也被检测到。

Two same sized experimental houses (floor : 7 m^2) were charged with cellulose fiber as insulation. One house (A house) has venting space on the outer side of the wall and the other (B house) has not.The room temperature and relative humidity were regulated at 22ﾟC and 80% from 7 to 22 o'clock. The regulations were kept for 2 and 4 weeks and the temperature, relative humidity in the insulation were measured in every hour at 40 points of each house. The following results were obtained :1) Differences in temperature between two houses were not detected.2) The absolute humidity gradient between both sides of the insulation were observed in A house. The humidity at the onter side of insulation was higher than that of inner side. On the contrary, no humidity gradient was observed in B house. This fact indicates that moisture transfer through the insulation.3) The moisuture content of the insulation above the cieling in B house was higher (nearly 1.2 times) than that of A house. Venting space in the wall affects to keep the moisture content in the insulation low.The vapor permeance of cellulose fiber was estimated in laboratory. Absolute humidity of both sides of the in sulation were kept constant and the amount of water vapor transfer during the insulation was measured.Though the amount of water vapor transfer through cellulose fiber depends on difference of humidity of both sides, that of glass fiber did not show same tendency. The vapor permeance of cellulose fiber estimated 1.9 and is nearly same value of the woodenn fiber board. The adsorption of moisture by cellulose fiber was also detected.