If you're in the market a way to keep your hard drive(s) cool, then Mikhailtech has a review just for you. Head on over and check out their Cyber Cooler HDD Cooler Roundup. They compare three HDD coolers from Cyber Cooler. here's a snip:
"The lowest temperature rise above ambient temperature was achieved by the HC-350 HDD cooler in an inverted drive orientation. I have always installed HDD with the opposite orientation figuring this would reduce the accumulation of dust settling onto the drive controller board both to keep things neater and avoid a layer of fuzzy insulation; however, with active cooling dust settling is no longer an issue here."