edmontondown 发表于 2013-1-2 23:56 7 U4 s6 a8 `3 U' c( S2 d! k( B1 Y
yes, may have something fell down on the other end of the hood vent
# f$ c; g% _( E& p0 o" j% g# m2 ZAt 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.