edmontondown 发表于 2013-1-2 23:56 ! l4 g, f4 X8 z8 @3 ?5 F- ryes, may have something fell down on the other end of the hood vent
" b3 @0 k. b, L0 @9 }; Q6 kAt 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.