Compressed air and vortex cooling tubes use are used for spot heating or cooling applications. Filtered, pressurized gas is injected into a chamber whose shape accelerates the gas to a high rate of rotation (over 1,000,000 rpm). The gas is then divided into two streams, one hot and one cold. Compressed air and vortex cooling tubes are less efficient than air conditioners and are often used for inexpensive spot cooling when compressed air is available. They generate cold air without refrigerants such as Freon, a registered trademark of DuPont. Air conditioning requires maintenance and can be expensive and difficult to install. Fans can provide inadequate cooling and may draw in dirty moist air, which can be another cause of failure. With no moving parts to wear out, compressed air and vortex cooling tubes can be used to cool electrical cabinets and control panels. Compressed air and vortex cooling tubes can also be used with machining and soldering operations, for cooling plastic injection molds, for dry inking on labels and bottles, and for dehumidifying gas operations. Compressed air and vortex cooling tubes can produce temperatures ranging from -50° to +260° F, flow rates from 1 to 150 SCFM, and refrigeration up to 10,000 Btu/hr. Commercial models designed for industrial applications can produce a temperature drop of about 80° F (45° C). Some compressed air and vortex cooling tubes provide a control valve with which users can adjust temperature, flow, and refrigeration. To achieve colder or warmer air temperatures, some air flow is typically lost. At 100 PSIG inlet pressure, compressed air and vortex cooling tubes with 100 PSIB of inlet pressure use from 2 to 100 SCFM of compressed air, depending on the size of the cooler. Inlet pressure can range from a minimum of 20 PSIG to a maximum of 250 PSIG. The compressed air in a vortex cooling tube must be filtered to 25 microns or less. Vortex cooling is rated in Btu/hr assuming 100 PSIG inlet pressure at 68° F. Compressed air and vortex cooling tubes can comply with ratings developed by the National Electrical Manufacturers Association (NEMA). Examples include NEMA 4 and NEMA 4x. Vortex coolers that are used to cool electrical cabinets may be listed by Underwriters Laboratories (UL) and bear the UL Mark.