Why Is Compressed Air So Cold

It creates a tornado or vortex of compressed air that separates the fluid into two air streams.

Why is compressed air so cold.

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. Eventually your hand gets cold. A fluid such as water or air that rotates around an axis like a tornado is called a vortex.

Anyone who has ever made use of the compressed air can knows that it can get icy cold. Cans of compressed air get cold while they re discharging because of a thermodynamic principle known as the adiabatic effect. This is perhaps why compressed air cylinders feel cold even before use. Compressed air cylinders are required to be kept out of direct sunlight to avoid gas expansion by direct heating and perhaps also due to phase change although no one seems to mention this explicitly.

One hot and one cold. 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. Minutephysics knows the actual reason why compressed air cans become so cold and will explain it. However that is not true.

The reason the can gets cold after being used is due to a process known as adiabatic cooling a property of thermodynamics. A vortex tube turns factory compressed air into two airstreams one very cold and one hot using no moving parts.