edmontondown 发表于 2013-1-2 23:56 2 n6 U( F2 N) r: @yes, may have something fell down on the other end of the hood vent
6 Y& r) ^! X0 C0 n! n: M' f" S$ oAt 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.