edmontondown 发表于 2013-1-2 23:56 . R! p$ x7 {3 y5 H: c, {yes, may have something fell down on the other end of the hood vent
0 b2 B& B) I: p# _ T7 c- uAt 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.