多半是管道不够大。比如参数是400CFM的抽油烟机意味着每分钟排出400立方英尺的空气。你还会看到一个参数,比如1.2sones。# W) R7 t' `* l
sone是排风的噪音评级,和分贝不同,更侧重主观感受,是线性的。0.9是比较静,如同洗手间顶的排风扇,工作中的冰箱。0.3是超静音,一般吸尘器则有50sones。6 b6 d; Y: S' C
I bought the same model and update to 7" tube(?). I think the noise problem is normal just because you have higher expectation since we paid more. I usually use level 3-4 and that is enough.