Why Do Compressed Air Cans/Gas Dusters Get REALLY Cold?

This video is about compressed air cans (aka gas dusters) and why they get cold when you spray them. They cool off because the refrigerant inside (1,1-difluoroethane) is under pressure and boils off when the pressure lowers, and energy lost to the latent heat of vaporization cools the can a lot. Difluoroethane normally boils at -25°C (-13°F), but under ~6 atm (6 bar, 600 kpa) it is a liquid at room temperature. The gas also cools off slightly due to the Joule-Thompson effect of fluid expansion through a throttled valve. Difluoroethane is heavier than air and water soluble, so it is recommended to use it in a ventilated environment to clean your keyboard, etc. Also, 1,1-difluoroethane is a potent greenhouse gas. It is also known as Freon 152a, Ethylidene difluoride, Ethylidene fluoride, HFC-152a, R-152a, and DFE.

[Minute Physics]