Yep not all do but many cans of compressed air aren t.
Why does compressed air get cold upside down.
As for why it gets cold.
A pocket of gas sits at the top of the can preventing liquid from spraying out when the can is right side up.
I found out in this video.
They are cans of propellent that are liquid under pressure but gas at stp you can google it boys if the liquid in the can is in two layers with the propellent at the top inverting it would cause the propellent to be expelled instead of the usually desired substance.
Gas duster also known as canned air or compressed air is a product used for cleaning or dusting electronic equipment and other sensitive devices that cannot be cleaned using water.
I was wondering exactly how cold it was.
This type of product is most often packaged as a can that when a trigger is pressed blasts a stream of compressed gas through a nozzle at the top.
Because these gases are compressed to liquid form when you turn the can upside down and press the nozzle liquid will come out before it turns to gas.
The duster can is made so it will just take air out because the intake is at the top like trying to suck on a slurpee with the straw at the top of the cup.
When compressed into the can this mixture takes fluid form.
The liquid which is sprayed while the can is upside down absorbs more heat as it changes from a liquid to a gas when sprayed.
The liquid chemical in the canned air absorbs heat from anything it comes in contact with once it s out of the can.
Similarly turn the can upside down and you re shooting out the liquid propellant instead.
Why does canned air get cold.
Hold your air can upside down and spray between the bottle and the sponges.
Since some of the gases are heavier than air when turned upside down the can will spray out the liquid mixture before it has had time to mix with the lighter gases.
It s pretty fun to do.
This same reason causes compressed air to feel cold as it expands and draws heat from its surroundings.
Turn that cup upside down and you get all that cold slurpee goodness.