To give you an idea of how big a unit you would need for heat disipitation.

See the pictures here :-

http://www.pwmaintenance.co.uk/air-blast-cooler-service/


Scroll down the page and take a look at the photos.
This is a pair of 400kw air blast coolers we installed a while back.
Each one will dump 400kw of heat from a water cooler compressor.
They are sized to give a 15 Deg temp differential.

Big cooling needs big coolers.