The Vortex Tube/$ is a device based on real-world physics/$. It splits the air/$ flowing into it into hot and cold/$ parts, heating up one side of the tube, and cooling down the opposite side. Be aware that the hot and cold sides do have a thermal connection, so it's more efficient to vent the cold side when you want to utilize the heat, and vice versa if you want to use the cold. This can be done with a Heat Sink/$.
Вихревая трубаpneumaticcraft:vortex_tubeWhen you place down or rotate a Vortex Tube/$, the hot end will face toward you. Note that each end has a narrow red or blue band indicating which is which.
Pressurized air is required to make the Vortex Tube/$ work. Higher pressure leads to greater temperature differentials, but air will also be used at a greater rate.
Crafting a Vortex Tube