Why Does Compressed Air Get Cold When Released

Travelling along this pressure gradient the gas expands and does work and this removes energy from the gas.

Why does compressed air get cold when released.

A gas initially at high pressure cools significantly when that pressure is released. The reason the can gets cold after being used is due to a process known as adiabatic cooling a property of thermodynamics. Eventually your hand gets cold. The process involved is the expansion of the gas.

Then the gas is released through a nozzle the gas expands again and cools. If the container is stored the temperature equalizes to the ambient temperature. The video will explain what really happens inside the compressed air cans. The cold temperature profile sneaks back towards the can because the air is such a lousy conductor of heat so the heat is all coming from the can.

When air or other gas is compressed work is done and the gas heats up. Cans of compressed air get cold while they re discharging because of a thermodynamic principle known as the adiabatic effect. 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. This is the principle operation of air conditioners refrigerators and other heat pumps.

The secret behind this freezing property of the cans is the do not shake warning that is mentioned on the can.