What about going to liquid immersion cooling? I live in a hot/humid climate so I completely understand the dilemma!
I heard about these guys on a SovereignBTC podcast:
www.grcooling.comProbably too much trouble. Just focus on moving lots of air, that's the cheapest way. There's a reason why you never see mega-farms doing this, they all have massive intake and exhaust fans and just stack the miners on shelves. If you can exchange the entire airspace of the room in a few minutes it never has a chance to get too hot....