I do have some heat issues but I manage OK. The basement is partially underground so the ambient temps never get much above 80 even in the hottest days of summer. I run 18/6 with the lights out period from 12-6 when the heat is highest. I also have negative pressure in my tent and pull a lot of air through to keep the heat down. But it still gets up in the mid 80s sometimes though the plants can handle that. I'm just growing for personal use so I don't need 100% perfect conditions.
For your closet you may want to try and get a fan mounted up high to get some of the hot, humid air back out of the space. As long as you're pulling it in from the bottom and exhausting it from the top, you'll be fine as long as your ambient temps aren't too high. That's where a tent is very useful. I can run the exhaust ducting out and away from my intake ducts to be sure I'm getting fresh air circulating.
I actually just posted about improving the closet in the new growers forum where Im hoping to get some solid responses. I know a lot of people would kill for the kinda space Ive got in this closet and just am NOT utilizing.
The ambient temp, so far on this grow, has never gone above 80- generally stays right at 78 though which is great. But last go round, it got unseasonably warm for about 2 days, and we just couldnt keep it cool in there without a/c. I think temps skyrocketed all the way to like...93 for about 3 days, and my plants HATED me. I honestly, thought they were going to die..they were so heat stressed and sad -
