Quote Originally Posted by lampost
^Thanks. Yeah, I haven't seen too many setups so I'm still curious as to how the fans are mounted. I was assuming you mounted it to the edge of the reflector or the edge of the tent, but that's a good point. I'll probably rig something to hang it from the inside somehow.

Also, I'm wondering how it would affect the air flow if I were to use a 6" fan and blow it through a 6"x4" reducer to exhaust. What will that restriction in the air path do to the total overall air flow? I'm thinking it would cause higher pressure between the fan and the reducer and slightly reduce the total air flow? Would this be negligible?
I've been told to always have the fan blow through the light instead of sucking the air through, because the hot air from the light is not good for the fan's bearing(s) and lubricant. I've seen two different types of flexible ducting, the kind that is like aluminized paper with a "slinky" type of framework, and some more rigid aluminum that provides its own structure, and accordions out to lengthen and turn (but be careful, it doesn't accordion back in). The latter is more expensive, but seems like it would provide less airflow resistance. Be careful about the aluminized paper kind. I used it in building my room, only to discover that some of the aluminum flaked off or cracked and was letting light in, like a starry night. If temps become an issue, you may have to draw all your cooling flow from outside the tent to avoid already-heated intake air. My reflectors are not at all airtight, so I lose way more airflow going through the lights than the reduction in diameter would cause. I run two 8in 700ish cfm fans through 3 lights each (w/ 6 inch flanges) and both flows exit through 1 8 inch exit.
senorx12562 Reviewed by senorx12562 on . Ventilation setup - Any problems with this? All air over light... I'm setting up a first grow and the last remaining hurdle is ensuring adequate ventilation. Here's the set up: 4' x 4' x 6'-6" Grow Tent w/ a 600W HPS. Not a cooltube, but Easycool (I think, basically same concept with larger reflector). It's got a 6-inch "port" for ducting on both ends. So, my grow room has a volume of 104 CF. The grow tent I'm getting has 4-inch vents, and it seems the largest fan I can find in a 4-inch inline is like 172 CFM. This is the expensive Vortex. So, Rating: 5