2007-03-29 10:39:32 · 6 answers · asked by dark_angel_360 2 in Cars & Transportation ➔ Maintenance & Repairs
As the can empties, the pressure inside the can reduces and causes the can to feel cold to the touch. When the can is not being used, pressure stabilizes and the can temperature is just about the same as ambient.
2007-03-29 10:45:47 · answer #1 · answered by Arthur O 5 · 0⤊ 0⤋
The above answers are not correct. A vacuum is not created when you empty the can. If that was the case, the outside air pressure would force air into the can!
The air pressure doesn't stabilize after you stop using it either. When you stop pressing the button, the can's air is separated from the outside air. It is the temperature that stabilzes over time.
The reason the can chills after using it is because the can is initially pressurized before use. Pressing the button opens the contents to the outside air, which is a much lower pressure and the air rushes from the can in an attempt to equalize the pressure. The overall internal energy in the can plumits as the pressure rapidly drops, which also caused the temperature to drop with it. It is the same process in which an air conditioner works. A refrigerant is compressed, raising enthalpy(and temp), then is cooled to the outside air temp via a heat exchanger. Then the pressure is dropped quickly, lowering enthalpy and with it temperature. The chilled refrigerant is then pumped through another heat exchanger in contact with your house's air, absorbing your house's air's energy and thus cooling it. The refrigerent is then compressed and the process is started all over again.
2007-03-29 18:00:31 · answer #2 · answered by kdog 4 · 2⤊ 0⤋
kdog sure uses a lot of words. Too bad they don't mean anything. The can gets cold because the liquid inside turns to gas when you use it. It's the same reason water evaporating is cold. Air conditioners do the exact same thing. They just turn the gas back into liquid and run it through again instead of dumping it into the air. CO2 fire extinguishers get frost on the nozzles for the same reason.
2007-03-29 19:55:56 · answer #3 · answered by Nomadd 7 · 1⤊ 0⤋
Yes, it is. When you spray a little air out of it, there is a slight vacuum built up inside the can that creates that effect.
2007-03-29 17:46:59 · answer #4 · answered by vgordon_90 5 · 0⤊ 1⤋
nope that is nornal but if you turn it up side down and spray it the liquid that comes out can cause frost bite
2007-03-29 17:45:56 · answer #5 · answered by a74impala2000 2 · 0⤊ 0⤋
Temperature/Pressure relationship is the answer.
2007-03-29 19:15:50 · answer #6 · answered by This is Fun 2 · 0⤊ 0⤋