Think as how long and how much it takes for a cold glass of water to have water drops outside the glass. That is condensation of said humidity. This is what worries me. The head from the S9 and the cold from the garage.
You're doin it wrong mate! you don't have a cold miner in hot conditions (like a cold glass of water on a warm day). You have a hot miner in cold conditions, more like a hot cup of coffee on a cold day. Ever seen condensation on a coffee cup in the winter???
As long as they are on and producing heat condensation will not be an issue.