edmontondown 发表于 2013-1-2 23:56 8 B8 B. N% Y4 k3 b- ~
yes, may have something fell down on the other end of the hood vent
2 `0 [$ e/ ?- V7 s& L- N+ I* m6 P) B' eAt the other end(outside) of the vent duct, there is usually a metal cover for the opening, it can swing up and down and if it is a windy day, it will be blown swinging, thus making a kind of banging noise.