Thanks for the link NiHaoMike. That looks very interesting.
There was one guy here JoshV06 who had over 150 mining units in Houston, Texas which is as hot and humid as it gets.
It looks like he went out of business though.
The location I'm considering wouldn't be as bad as Houston.
If you're talking about cost of cooling you must be talking about air conditioning. Humidity matters with AC.
With fresh air cooling humidity doesn't matter. Your biggest challenge with fresh air cooling is air circulation.
An ambient tempterature of 32C is ok if you can exhaust the heat well. A couple of box fans is a lot cheaper
than AC.
I haven't done the math but the cost of air conditioning will probably kill any profit potential.
There was another recent thread discussing the effects of humidity.