I just figure if you have a major humidity issue like that, you need a damn good solution and a dehumidifier is sort of a guaranteed solution- whether it puts off to much heat or not can be an issue of its own but id rather my plants be a little warm than soaking wet.
True , but we don't know he has a humidity issue, just it climbs rapidly because he's recirculating his air.
Which is 100% going to happen when recirculating the same air in a small space.
Neither of us know his true natural climate so its guess work as to if he would need a dehu if he were venting out.
But certainly recirculating the air isn't the way forward, even if he uses a dehu hes going to have to add co2 because its going to diminish without fresh air coming in.
I did the same thing when I moved into my new house two winters ago, trying to avoid venting my heat because it was cold and I had 100% rh in a few days. Venting into the room had it back down to 55% (big room though, not a closet) and venting up the chimney had it to 45%