probably something to do with getting all that moisture on their hashblades 
You and your butt buddy must be related because a AC units help pull the moisture out of the air not add to it. Again neither have even seen it setup to determine what the outcome will be on affecting the efficiency of the miners connected to it. He sure isn't a NASA engineer because he should know that cooler electronics perform better.
If the miner speed can be increased by cooling it and the gain is more then the cost to operate the compressor which is very low cost, then profits can be increased. Simple as that. I guess it depends on how many pennies you want to get out of your miners before they are no longer profitable.
I never said that cooler wasn't beneficial. I said your plan wasn't cost effective. you're increasing your electric use by 20% to get it. when you can get satisfactory cooling by just using ventilation instead, which is what all the big time miner operations do. some ducting to bring outside air to your miners (you mentioned there was snow, so you obviously live in a cold climate) and some fans are all that is needed. and will be cheaper and less complicated.