edmontondown 发表于 2013-1-2 23:56 ( Y; y0 V% v2 Y
yes, may have something fell down on the other end of the hood vent
& b! w; k: H0 N: i e6 \3 N" C( l
At 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.