i been so busy DreadedHermie so sorry took so long to reply it has to be Very Stealth the window is on the back side of the house facing the backyard and about 30-35 feet from the fence, on all sides are neighbors yard i'am also running a 8in inline fan and it's kinda loud but bout to buy a fan speed controller i was think about using a 8in sunbeam double fan which is 2ftw and 1fth for the window box or many be a 4in inline can fan
this is why took so long to reply