edmontondown 发表于 2013-1-2 23:56 4 |0 z0 _3 x2 z" h8 c) ]+ {yes, may have something fell down on the other end of the hood vent
# A' z* y; a4 [, T; q3 i% j& cAt 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.