How many inline fans do i need in my 2'7x4'11x6'7 tent IS it just one or do you need one to bring the air in and bring the air out. And what cfm should i be looking at?
Your tent is around 105 cu ft (rounded to the nearest foot - 3x5x7). You can just have 1 inline fan to exhaust, and if you can....1 inline fan to pull in fresh air from outside. You will want each fan to have a cfm rating of AT LEAST your area, in this case.... ~105 cu ft.
No, you would want to step up the exhaust fan to probably pull more air than a 100cfm one can. I am using a 600w (air cooled hood) in my grow in the sig, and have a 400cfm fan (6" inline) pulling air through a carbon scrubber in a small closet around 180 cu.ft and it keeps my temps down to 76F in the room with the ballast at 100% output. You can get away with a smaller fan pulling air in from outside your tent however. I would suggest getting as large of a fan as you can afford to be hooked to a carbon filter to control odor, and also to pull out the heat from that tent. 600w lights put out a decent amount of heat. If my inline fan is off, my room gets to over 100F pretty quickly....so ventilation and heat exhaust is imperative.