According to Environmental Conditions and Disk Reliability in Free-cooled Datacenters:
Based on our experience and observations, we conclude that high relative humidity degrades reliability significantly, having a much more substantial impact than temperature or temperature variation.
A ZDNet article examines the paper:
- Relative humidity is the major reliability factor - more so than temperature - even when the data center is operating within industry standards.
- [...]
- High temperatures are not harmless, but are much less significant than other factors.
Are these results correct?