A study on environmental factors on disk reliability in free-cooled datacenters by Rutgers University, GoDaddy and Microsoft has found that hard drives are more likely to fail because of high levels of humidity [PDF] [rackcdn.com] than high temperature. The paper notes that humidity related malfunctions of the driver controller / adapter are the dominant cause of drive failure. Software availability techniques can however mask this problem and enable free-cooled operation that saves costs.
Put a tube from the filter hole to somewhere hot and dry?
Free cooling - The use of low external air temperature for cooling to save power.