I'm going to have an led setup, they don't put of much heat, but I'll have a little clone box with a mother plant with t5s 2 bulbs 4ft 54w ea. It's a 6Lx6wx8.5h closet, there's about a 1-2 inch gap under the door , with the miscellaneous gaps around it. How much cfm should I use and inline or an air duct fan. My strain is alcupolco gold, with a sog setup.
its true that plants do breath, and in nature its very rare there is no wind, so keep a fan in there to let your plant breath, now to the heat, if you cant maintain 70f/25c cause its too hot then yes you need to extract that heat, sorry but its trail and error here, too hot your plant will shut down same as if it was too cold, just leave your inlet passive