Hay Rob.
I'm in the same boat as you on this, its the whole connecting stuff i just cant figure out myself.
So far i have only put the box together its 4Wx4Dx6H and thats all i have done to date. I will be using a 600w MH/HPS Switchable ballast with an Air-Cooled reflector. All i know is that i have to put my passive intakes on the bottom left and put my exhaust fan top right. What size these need to be + a carbon filter, i just dont know. One day in the near future i might figure it out. But i dont see that happening for a while. If there's anyone that would like to help 2 new growers out, it would be great.
He he, can i join the "noobies that aint got s f'ing clue about ventilation" gang?
Greenstuff, i think youve got the basics there. Whats refered to as "passive intake" i think is basically a hole with a vent cover, the lower the better. Then at the top you will have an extraction fan...fitted to this inside the cab is carbon filter, so all that stinky air is sucked through the carbon filter before passing through the fan on its way out, clean and not reeking of weed.
Awesome carbon filter DIY tutorial here...
https://www.rollitup.org/do-yourself/101248-best-diy-ez-walmart-carbon.html
Yknow i think of all areas of setting up a grow room, when it comes to ventilation, there really isnt a right way and a wrong way...the objectives are simple: you have a very warm and smelly space, so a) you need a way for fresh air to get in, b) a way to push the hot stinky air out and c) a way to clean the air before it goes out, and any which way you achieve this is up to you...
i mean thats just what ive learned from here in the last few weeks...
cheers