PC cleaning: why is vacuuming a static electricity risk to internal components but not using compressed air?

Both involve using moving air to remove dust and other debris- so why the stigma around using a vacuum cleaner nozzle?

In both cases you are just moving air (negative vs positive pressure), so the static risk should be the same, no?

Also, compressed air causes a massive temperature drop and can cause a small amount of condensation on components during cleaning.

Why is compressed air, therefore, considered better than vacuuming? Has anyone actually damaged any electronic equipment with vacuuming before?

(I've been doing it for years with nothing but fantastic results.)

Solution 1:

A vacuum isn't directional. Thus you have to have the end very close to what you're cleaning--if you have a static charge on it you might end up too close and a spark would jump.

Compressed air is directional, though. You'll be holding it much farther from what you're cleaning--there's no chance of a spark jumping to the target (although you could still zap something off to the side that you got too close to.)

Obviously you must beware of condensation when dealing with compressed air. If that were the slightest risk (as I live in the desert it rarely is) I would discharge some air in a harmless direction first.

Solution 2:

In a vacuum cleaner, dust particles are drawn into the plastic tube and it is these particles that cause the build up of static elecrticity.

In the case of a compressed-air source, only clean air should be moving against the nozzle.

There is also a temptation to hold the nozzle close to the part being cleaned. A typical domestic vacuum cleaner is a relatively clumsy device. There may therefore be more likelihood of the charged nozzle contacting vulnerable devices.