Hi
What people are doing to overcome this problem?
Air con won't be feasible as it consumes electricity.
What about Evoperative cooling?
Proper ventilation. We use exhaust fans to expel the hot air that is coming out from the miners and at the same time suck in colder fresh air from outside. Exhaust fans are cheaper to operate than air-conditioning system.
I will not recommend evaporative cooling because it will humidify the air which is not good for electronic devices. This is good if you are in a very very dry climate area. But if you are in a humid area, this will be bad to your miners. SO i will not risk it.
There are many ventilation threads here already that you can read through the discussions to get some ideas.