Solved Using compressed air.

[Frank1]

I bought a can of compressed air to clean the keyboard of my laptop. When I used it, the air came out very cold. I'm sure that is not unusual since that's the way air conditioners work. However it made the keyboard very frosty and when it thawed out the keyboard was a little damp. It makes me wonder if the dampness is harming the keyboard.

 

[AddRAM]

Should have been just normal dry air. Where was it stored.

 

[Frank1]

Should have been just normal dry air. Where was it stored.

It's a new can that I just bought. But after reading your post it made me realize that I may have made a mistake. Before I used it the first time I read the instructions which said to " Hold can upright and pull trigger to clear valve of any of any liquid." I did that when I first used it. Then after reading your post I wondered if it was possible that when I cleared it the first time that I didn't hold it long enough to clear all the liquid. So, just now, I cleared it again but did it for a longer period of time and tried it on my laptop keyboard. It did a good job and there was no problem of frosting. Thank you for your answer.

 

[ICIT2LOL]

Mate you let it out far too quickly the drop in pressure actually makes any compressed gas drop in temperature that is like has been said how a refrigerator or air con works.

Also the long blast will make the "concentrate" condense the water vapour in the surrounding air onto the cooled surface (of your keyboard) just like when you breath on a frosty window in the winter or even cleaning your specs

You just need short sharp bursts, and as precaution never blow your skin with this stuff just like CO2 extinguishers they can lower the temperature to a point where you will get frostbite

 

[Frank1]

Mate you let it out far too quickly the drop in pressure actually makes any compressed gas drop in temperature that is like has been said how a refrigerator or air con works.

Also the long blast will make the "concentrate" condense the water vapour in the surrounding air onto the cooled surface (of your keyboard) just like when you breath on a frosty window in the winter or even cleaning your specs

You just need short sharp bursts, and as precaution never blow your skin with this stuff just like CO2 extinguishers they can lower the temperature to a point where you will get frostbite

That's another mistake I made. I was making the loooooooong blasts. I'll try the short ones. Well---that's only two mistakes I've made with it so far and I've had it for a full 6 hours.

 

[ICIT2LOL]

Mate you let it out far too quickly the drop in pressure actually makes any compressed gas drop in temperature that is like has been said how a refrigerator or air con works.

Also the long blast will make the "concentrate" condense the water vapour in the surrounding air onto the cooled surface (of your keyboard) just like when you breath on a frosty window in the winter or even cleaning your specs

You just need short sharp bursts, and as precaution never blow your skin with this stuff just like CO2 extinguishers they can lower the temperature to a point where you will get frostbite

That's another mistake I made. I was making the loooooooong blasts. I'll try the short ones. Well---that's only two mistakes I've made with it so far and I've had it for a full 6 hours.

LOL!! Mate I found out the hard way to if it is of any consolation!

Wonder if it would work making iced coffee LOL!!

On a serious note it is very cold and what I said about frostbite is real danger with this stuff and CO2 - that looks fun but after my fire training I found out again the hard way that you can get really hurt with those extinguishers at the metal end where the trigger gear is attached to the cylinder and I don't think they make it clear enough for owners of them that that danger exists. That is not taking into account the odd idiot who plays with the things.

 

[bobkn]

The canned "air" that I have isn't compressed gas at all. It's some sort of volatile material that is liquid at room temperature at high pressure. When you release the pressure, it boils off, making lots of gas. The manufacturers do that because it'd take a rather high pressure to store much compressed air in a small volume. A thin, cheap pressure vessel wouldn't serve. Given the warnings on the can about inhalant abuse, it's not air or air like.

It's probably a good idea to avoid spraying the liquid on your electronics, although similar stuff is used for diagnosing intermittently bad electronics.

If you sprayed the liquid over your skin long enough, you could probably get a case of frostbite.

 

[gregrocker]

So this is why the can always freezes in my hand and then stops working until I sit it down for awhile?

Need to be using even shorter bursts than 5-10 second ones?

 

[Nigsy]

It's basic physics guys.

When the gas is compressed to liquid form in the container, thats a lot of pent up energy.

When you release it, it expands back into gas and it uses that energy and energy (stored as heat)in the air around it to return to a gaseous state - As you are taking heat energy away from it and the air around you get condensation and then freezing. As you all rightly say - This is the way condensing units work in fridges and air con.

 

[ICIT2LOL]

Yes and I think a fair bit of the released gas would be the propellant again a condensed gas that drops dramatically in temperature when the pressure is dropped.

An analogy would be like the astronaut in space having a puncture to his spacesuit the fluid within the body would boil off in an instant.
Another example is that when you lower the pressure in a space say in a sealed vessel that water within that vessel will boil at a lower temperature in relation to the decrease in pressure.
The classic example is at sea level that water boils at 100C whereas at the top of say My Everest the temp might be one third of 100C as the pressure is one third of the pressure at sea level - thats a guess but the lower the pressure the lower the boiling point of gaseous materials.

See - Pressure and Boiling Points of Water oops and this http://www.engineeringtoolbox.com/boiling-points-water-altitude-d_1344.html

 

[marsmimar]

One more caution - always hold the can in an upright position. Tilting it or turning it upside down can release the liquid. Found that out the hrd way.

 

[ICIT2LOL]

One more caution - always hold the can in an upright position. Tilting it or turning it upside down can release the liquid. Found that out the hrd way.

Absolutely right M it is because there is no tube inside to the bottom of the containment vessel as in those spray bottles the lowered pressure at the top is where the air turns from a liquid to a gas - so inverting the vessel actually fills the "top" of the vessel with the liquid.

I know I keep on about it but this is a timely warning that the same happens with CO2 fire extinguishers they are NOT things to be playing with or handilng without due care when used.

 

[AddRAM]

I use my 180 psi gas compressor to clean keyboards, sometimes they end up in the neighbors yard.