Be careful blowing out fans with compressed air

[FlyingPenguin]

I got into this discussion on Red-Eye forums and discovered a lot of people don't know about this, so I thought I'd post it here.

When you blow the dust off your fans you need to make sure you NEVER let a fan (any fan) free-spin when you blow it out. Instead put your finger on the fan to keep it from spinning, or jam it with a PLASTIC straw if you can't put your finger on the fan (like the PSU fan).

Fans are not designed to spin much faster than 2000 RPM, and some of the newer low-noise fans even less. When you hit them with compressed air they can easily hit 10K or 30K RPM. That satisfying "WHEEEEEEE!" sound is the sound of friction and the sound of the bearings frying. Doesn't take much to destroy bearings being forced 10 to 20 times beyond their design speeds.

"Now you know, and knowing is half the battle."

[nitro237]

Wow, never realized that. Thanks mile

[NubyCanuby_OFC]

I guess I'll have to use the straw method. It's hard to hold the fan when you've got a leaf blower in the other hand. Rofl

[nexus_7]

But its so much fun making them make that noise.

[MegaVectra]

Been doing it for years. Never had a problem.

[ZYFER]

Yeah, nice mention to everyone. Already knew this, kind of simple physics really. Obviously, you know there are going to be issues when you try having a fan spin faster than it was designed to do so. (Whether you meant to do it or not)

It is not likely you are going to just turn it on and blam they won't work anymore. You just end up shortening the lifespan of the fan. Unless you are a compressed air can freak, who needs to blow their fans everyday, you are not likely to notice this readily.

It is kind of like cigarette smokers. Sure, the ones who smoke less are not going to notice the affects so soon, but that person going through 4 packs a day will surely do.

Don't make this think you should deter cleaning your fans though, you certainly need to do so. If you let the dust collect, your fan has to work harder to spin, which shortens its life span just the same.

[TheSovereign]

u forgot to mention that since they are perm magnet motors they generate electricity and may fry something

[ZYFER]

On a completely unrelated topic, I wonder if static electricity is enough to start someone's heart...

[FlyingPenguin]

We had a kid we hired at the TV production company I used to work for, who was doing equipment cleaning and basic maintenance and I THOUGHT someone had taught him how to do this right.

We started having a spate of fan failures so one day I watch while he dusts out a rather expensive piece of video gear and he's using the compressor in the shop to blow it out and just going out of his way to make those fans spin as fast as possible, and not just for a few seconds either... needless to say we had a LONG talk.

Any yes, as Sov mentioned, a fan is basically a generator when you spin it. I have seen voltage generated by a spinning fan damage the fan control electronics (that was one of the issues we had when this kid in the shop was doing his thing). Get that fan up to 30K RPM and you can generate some substantial voltage.

[normalicy]

Yeah, I learned this a while ago. Never thought about the voltage thing though, that's a good point.

[darcy]

I got into this discussion on Red-Eye forums and discovered a lot of people don't know about this, so I thought I'd post it here.

When you blow the dust off your fans you need to make sure you NEVER let a fan (any fan) free-spin when you blow it out. Instead put your finger on the fan to keep it from spinning, or jam it with a PLASTIC straw if you can't put your finger on the fan (like the PSU fan).

my tosh easily got overheated. that was 1 of the first things i learned.
i do the same w/my notepad cooler fans, too.

[MegaVectra]

*I have been doing it for years, but only in short bursts.