I saw a small data center (4 racks) get from 18C to 55C in one hour when the chillers failed. And that was the air temperature, not the server temperature. In t

I saw a small data center (4 racks) get from 18C to 55C in one hour when the chillers failed. And that was the air temperature, not the server temperature. In theory you can just open the doors, but then you cannot control the humidity.