[Gooserider]

Capt Foo is on the right track - a normal civilian grade hard drive is NOT sealed (there are some special sealed military / aerospace drives, but those aren't something most of us will ever encounter) It will have a small vent somewhere on the drive housing - most drives the vent is under the drive board and not visible, but some IBM drives have it on the lid, with a big arrow pointing at it saying "DON'T BLOCK THIS HOLE" The vent leads to a HEPA type air filter and is mostly for air pressure equalisation, it doesn't actually get much circulation, however air will go in and out with pressure changes and / or as the air in the drive expands and contracts due to temp changes.

The air is a VITAL part of the drive mechanism, the drive would fail catastropically with out it. The spinning platters move the air around in the drive, this creates an airfoil lift effect on the hard drive head and lifts it off the disk surface. The lift allows the head to maintain just the right distance above the drive surface for it to read and write properly.

So no MC, putting your drive in a vaccum box would not work - it would get rid of the turbulence and heat all right, but only because it destroyed the drive!

Gooserider