Minutephysics knows the actual reason why compressed air cans become so cold and will explain it.
Why does compressed air get cold when released.
Eventually your hand gets cold.
The reason the can gets cold after being used is due to a process known as adiabatic cooling a property of thermodynamics.
The process involved is the expansion of the gas.
If the container is stored the temperature equalizes to the ambient temperature.
The video will explain what really happens inside the compressed air cans.
When air or other gas is compressed work is done and the gas heats up.
When you pressurize a gas by compressing it into a container you re putting all those molecules into a smaller volume of space and you re adding potential energy by the compression.
Travelling along this pressure gradient the gas expands and does work and this removes energy from the gas.
Metal however feels cold to touch even when at environment temperature due to the high thermal conductivity.
Then the gas is released through a nozzle the gas expands again and cools.
Cans of compressed air get cold while they re discharging because of a thermodynamic principle known as the adiabatic effect.
This is the principle operation of air conditioners refrigerators and other heat pumps.
A gas initially at high pressure cools significantly when that pressure is released.