Vortex Tube

Vortex Tube, compressed air in middle nipple, cold air out short end, hot out long end.
Co-worker showed us one he made from 1/2" pipe in early 1980's. Obtained some drawings about the same time but never attempted to make one. Saw commercial units a few years later cooling mill cutters in plastic instrument panels. In 2016 This Old Tony made a youtube video about them. Saw that video again recently & realized I now had a 3d Printer.

I sized this for 3/8" brass "hobby" tubing & an aquarium air valve on inlet.
Hot tube was 9-5/8" long, Cold tube was 2-3/8". That's about right & totals at the 12" stock length. Fool with these lengths & washer sizes as you wish. You'll also need a fiddly little screw & double nuts to hold the valve disk in place.

Made a larger version originally but this uses a lot less air & the compressor shuts off sometimes.