The vortex tube is a compact cooling and cooling source, with models ranging in length from 6 to 13 inches (150 to 330 mm) and cooling capacity from 100 to 6000 BTU/ hour (29 to 1,757 watts). The performance of the vortex tube can be easily adjusted by changing the intake pressure, the ratio of cold air to exhaust, or by changing the generator of the vortex tube itself. Vortex tubes are commonly used for cooling, but can also be used for heating applications where hot air is simply directed to the application.