micky wrote:
Can you damage a case fan by vacuuming the air vents from the outside?

(I have a Dell Optiplex 775 with the original fan. )

It seems more than safe to me, but I happened to read the manual for a
Noctua fan and it says not to use a vacuum cleaner or it may apply
"excessive force to the fan". I find that hard to believe. I've pushed
on the vanes of other 3, 4, and 5" fans and they don't bend at all with
the kind of force vacuum cleaners exert. In fact I think they would be
hard to break. Are Noctua fans more fragile than others?

Your local computer store must love you.

"Well, I just got this new fan from you on Tuesday.
I was minding my own business, vacuuming the rug or
something, and the blades just flew off the fan!!!
I want my money back."

*******

To be semi-serious for a moment, even cleaning a fan
with a rag with solvent (isopropyl) on it,
*can ruin the bearing*. I've done it.

Some bearings on fans, have an internal spring to return
the blade to home position. If you tug on the hub hard
enough, you can dislodge the spring.

You need to treat the thing like Royalty, if
you're going to clean it. That means a little bit
of solvent (to act as a dust magnet). Hold the
fan blade from the back, so none of your pressure
is transferred to the hub. And so on.

To do a good job, in some cases you might want
to remove the four mounting devices (screws or
clips), and work on it outside the computer.

Dells tend to be a little special, because they have
a high-power (100CFM) fan as a blower on the CPU
heatsink. And it doubles as a case ventilation fan.
So Dell tries to do everything with the one fan.
When the thermistor says the case is too hot, that
five-wire fan can really speed up. And then it sounds
like a vacuum cleaner.

For one of those, you wouldn't think of being lazy and
taking shortcuts. If you needed to clean it, you'd disassemble
the shroud and take it outside the PC and work on it. While
there are so-called "exact replacements" for fans like
that (with the five pin connector), only one or two companies
source them, so you could easily no longer have a source for
them. Whereas a lot of other computer designs, any old
replacement case fan would do.

Your Optiplex might not be that bad, but before you become
"abusive" with the fan, check on the Internet and see if
a replacement fan for the 755 is even available.

Paul