Disk drive temperature coolers may be waste of money.
These charts from the google study of 100,000 consumer-class ATA disk drive study show that you are probably throwing money away on disk drive coolers, as disks fail more often at LOWER temperatures. At the very least, have the drive cooling vendors supply data that proves that cooler disk drives last longer.
From the google analysis of 100,000 disk drives, Failure trends in a large disk drive population study
… In this study we report on the failure characteristics of consumer-grade disk drives … One of our key findings has been the lack of a consistent pattern of higher failure rates for higher temperature drives or for those drives at higher utilization levels. Such correlations have been repeatedly highlighted by previous studies, but we are unable to confirm them by observing our population. Although our data do not allow us to conclude that there is no such correlation, it provides strong evidence to suggest that other effects may be more prominent in affecting disk drive reliability in the context of a professionally managed data center deployment.
(Well, to be fair, hard disk drive coolers have their place … but only if your disks start to run around 45 degrees C, according to the Google report).