Stanley Blower Fan

anyone have any experience with these? How effective are they at exhausting air out of a room?

i use one in a 200 cu. ft. room and the blower works great. i have it connected to a cooltube 400w HPS i am usin 6" ducting connected to the fan. using a reducer to connect a 4" duct to the cooltube. reducer has holes so it will till vent the ceiling. 6" exhaust to outside. and an 8" passive intake.