[SOLVED] Is it important to unplug everything before using compressed air?

[spyguy]

I read once that you shouldn't use canned air while anything is plugged in. Why is this dangerous? Does it matter? Should I hold down the power button after to make sure theres no juice left in the components?

 

[Gam3r01]

It likely wouldnt matter much, but its a good practice if you plan on opening up and digging around in your case.
More important would be holding fans in place so the compressed air does not spin them.

 

[Paperdoc]

The cautionary notes you have seen are because some people have found that using compressed air can cause a fan to turn MUCH too rapidly (either forward or backward). Even with no electrical power applied this might damage the fan bearings. But with power applied also, it might damage electrical components of the fan when its speed is forced very high.

 

[jsmithepa]

10 different people will give you 10 different answers.

Me, if you are just taking care of a particular spot, don't bother to unplug anything, except for power of course needless to say ha-ha. If u are doing a full cleaning, comeon, u can't do a good job without at least unplugging the expansion boards.

More importantly, give the can a slight stir, shake it in a few gentle circular motion, and keep the can upright to avoid propellant from forming an aerosol (will come out as a mist, bad).

 

[iMatty]

Just don't use the can until the end the air will turn into some small drops of water and that can cause to short ur mobo or something so be careful else when you are cleaning a fan or a gpu hold the fans with your fingers so they don't spin to much to the point they break.

 

[Phillip Corcoran]

Short bursts with the can is best policy too, less risk of moisture coming out compared to long bursts.

As far as unplugging, all I unplug is the PSU mains cable ---- then short bursts with canned air --- I've never had any problems doing it that way.

 

[spyguy]

I always spray the can once or twice before I use it because it always sprays out mist after its been sitting. I always thought shaking it would make it worse but if I shake/stir it and theres no visible moisture/mist then its good to go?

 

[DavidM012]

It's not mist it's rapid condensation of moisture in the air because when you release the pressure from the aerosol the air cools rapidly like a refridgerator the compressor creates pressure of the liquid coolant and then when the refridgerant is released under pressure it expands rapidly and turns into a gas that creates the cooling effect.

Normally in a fridge that all happens in the closed loop of the condenser tubes in the ice box when you spray compressed air from a can into the air if it suddenly and sharply cools it below ambient temperature, water precipitates out of the air. Think of it as a portable a rain cloud. That puts your components at risk of shorting out, even a single drip of liquid could in the wrong place take out the entire system, in any case it would be very inconvenient to have to replace components because of that!

if you hold the can upside down it happens more often probably because the compressed air ejects more rapidly from the container. so if you go in at an odd angle you would shower condensation on the components (as well as spinning the fans up too fast) all of which is simply a bad idea where there is electricity. You could say that, yeah but the condensate is pure water so shouldn't be conductive but then there are a lot of particulates and interesting molecules in the ambient air as well that contaminates it instantly. So it would be conductive. It all happens very fast too.

The expanding compressed air also rapidly cools any surfaces it contacts particularly the metal of your pc chassis for example, you can make it form a streak of ice crystals all which will rapidly melt creating a puddle of water.

 

[CountMike]

It's a safe practice to turn off PSU or disconnect from power whenever you work inside the case. Even when not running there's some power to MB and other components and certainly in the PSU itself. It takes only a second, why risk it ?