In an attempt to keep operating temperatures and fan noise down how can I clean out servers and desktops that have accumulated dust in their cases, heat sinks, and other crannies? Is there any way that I can slow the accumulation of dust in PCs on the shop floor? Bonus points for ways that keep server downtime to a minimum.
This really depends on the specific casings involved in each, er, case. Generally I find that a vacuum cleaner is my best friend when cleaning out equipment. If there are speed settings then set them down relatively low.
You can also buy special computer attachments for some vacuum cleaners, for getting into smaller spaces etc.
For tougher things it is sometimes handy to have access to an air compressor - we used to have one of these floating around at work for cleaning purposes.
If you follow the suggestions given here, be wary of the ability of a fast-moving air stream to generate a large static charge (and for said charge to play nasty with electronics). As Wayne Koorts said,
If there are speed settings then set them down relatively low.
but grounding your vacuum or compressed-air nozzle, or your wrist that holds same, will probably be even more useful.