Dark Room vents (Passive intake)

I have been searching for info on use? Whats everybody know about them it looks like they could safe me a bit of room. Whats the passive cfm on them though? Anybody got pictures of them in use?

I don't think they really compare to an inline centrifugal fan (e.g. Fantech). Maybe they make a good choice to circulate air in the grow space, but I don't know how well they would cool a light if that's what you need.

There is no comparison to a fan. It is a Passive intake.

Passive intake works well if you have an inline fan exhausting out of the tent creating negative pressure. I run a DR80 and the passive intakes just looks like smaller ducting socks

Right but do you use dark room vents or know anybody that does.

http://www.builderdepot.com/seo/midgetlouver/11367_Midget_Louver_Darkroom_Vent_Black_-_4-inch.ihtml