Nothing wrong with evaporative cooling!
I wouldn’t have thought these guys would have an issue with legionella, their company background is in the design and build of operating theatres:
http://www.bladeroom.com/company-background.php
Open body surgery is about the only area I can think of that requires even stricter control and filtration of air than a data centre.
From what I know of evaporative coolers, they all use a high level of bacteria disinfecting & filtration (you will struggle to buy one that isn’t).
I don’t think they even use that much water as they are re-circulated and disinfected constantly, only flushing every so often.
Biting the hand that feeds IT
