Jim Lux <[EMAIL PROTECTED]> wrote: > >>quiet down a rack because to first order sound insulation == heat > >>insulation. \ > > Actually, no.. good acoustic isolation is not good thermal > isolation. Sure, things like fiberglass batts provide thermal > insulation and also (slightly) attenuate high frequencies.
I guess I should have used => or some other "implies". Sound insulators tend to be good heat insulators, heat insulators are generally not good sound insulators. I spent way too long trying to quiet down a rack when it had to live in a classroom. Mass loaded vinyl on all 4 sides worked fairly well to stop the noise coming out that way, but then it just turned into a big speaker enclosure and directed nearly as much sound out the fan holes, where it bounced off the ceiling and floor. And the rack exhaust fans (2 very high capacity 120mm fans on the top) were not able to keep it cool when it was fully sound insulated. The rated capacity of those two fans was more than the sum of all the little ones in the nodes, but the air flow was too restricted, I think mostly by the narrow space between the node's front panels and the front insulator panel. Thankfully it finally moved to a machine room and the noise problem went away. Anyway, it is a much easier to sound insulate a room than it is a single noisy rack. David Mathog [EMAIL PROTECTED] Manager, Sequence Analysis Facility, Biology Division, Caltech _______________________________________________ Beowulf mailing list, Beowulf@beowulf.org To change your subscription (digest mode or unsubscribe) visit http://www.beowulf.org/mailman/listinfo/beowulf
