Dust can be a major problem for computers. Its accumulation in vents, heat-sinks and fans can block cooling air (making equipment less reliable), and its accumulation in power transformers may cause explosions and electrical fires.
One computer's PSU exploded after dust accumulated in the power transformer. In this case, the computer had been switched off over a weekend, and when started up on Monday morning, the PSU exploded with a small cloud of black, acrid smoke. It is possible the dust had accumulated some moisture over the weekend, and had become sufficiently conductive to short-circuit the power circuits. In consequence, every electrical component attached to that PSU was destroyed—the motherboard, processor, memory, hard drive, optical drives etc., all were irreparably damaged by an electrical spike resulting from the preventable failure of the PSU.
Remediation
We recommend vacuum cleaning thoroughly inside your computer case every three to twelve months, depending on how dusty the ambient environment is. Use a small brush and vacuum cleaner to ensure that all accessible grilles, vents, heat-sinks and fans are free from dust. This will help your computer run cooler, quieter and more reliably.
When you do this you should take some precautions: don’t brush components that are sensitive to static electricity such as surfaces and pins of semiconductor microchips, and before opening your computer case, shut down your computer and switch off the power at the socket and at the PSU, leaving cables plugged in to help earth the device and drain away static electrical charges.
DISCLAIMER: We are not responsible for any damage you might do to your electronic equipment. The procedures we recommend (which have never caused us any problems) should only be performed by people who understand the risks and know how to control them.
Prevention
Purchase a non-ionising 3M Filtrete air filter, to reduce ambient dust levels. This will also reduce the presence of airborne allergens and support the health & effectiveness of any residents or workers present.
Risks, noise and air conditioning requirements can be minimised by selecting environmentally friendly low-power components that will help minimise air flow through electrical equipment, thereby reducing the rate of dust deposition. Consider using low-speed PWM fans and placing dust filters on the air grilles of your computer.