So you've basically given me the motivation to get my room finished by the end of this weekend!! I've built the walls and will put them in-place either today or tomorrow.. Then, I just need to build a door and run the rest of my ventilation.. I painted the walls white yesterday, and have done as much cleaning as I can.. I fully agree w/ the "open air" design because I think that alone w/ help w/ environmental controls such as temperature.. I think w/ that much air volume vs. a tent, it'll be easier to keep the temps regulated.. I'm going to be using 3 carbon filters w/ associated fans (4" and 6"), having the fan for the lights on the timer, but the others on speed controllers so that it can retain heat in the winter and vent it off in the summer.. The only thing I'm not going to be concerned with is the RH once the Summer rolls around..
Not sure where you're at or how popular Craigslist is near you, but I find a TON of cheap or free building materials on there.. I've seen people giving away 80lbs bags of concrete or Portland cement, studs, hardware, sheet metal, etc... If you don't check there, it may not be a bad idea to look from time to time to see if there's anything you can get for the low on there!!
