..... i tried an inline fan that said up to 188 cfm, garbage
damm! I run a 400 hps in a hood w/ 2 pc fans,1 @ the start of duct pushing air & 1 @ the end sucking air out -straight shot,4 in duct, no bends or filter. & the hood is warm but not hot to the touch. the air is drawn from another room in the basement so its cool going in.I have a 635 cfm fan running through an enclosed Magnum-XXXL hood with a 1000w HPS and it still gets pretty hot in there so I added a portable A/C unit. I'd recommend something above 400 cfm for sure