There are no moving parts. You connect the inlet near my thumb to an ambient (room) temperature air supply. Really, really hot air comes out the end near my forefinger. Really, really cold air comes out the other end near the base of my palm. That little orange label says "CAUTION: Hot and cold surfaces" and it's not kidding. If the air supply is 8 cubic feet per minute at 100 psi, the hot end is over 100F hotter than the input air temperature and the cold end is over 100F colder than the input air temperature and can provide over 500 BTUs of cooling.
That's a pretty neat trick for something with no moving parts. Another neat trick is that until recently folks were still debating the physics behind how it works:
...for a long time the empirical studies made the vortex tube effect appear enigmatic and its explanation – a matter of debate.In fact, the science wasn't totally settled until 2012:
This equation was published in 2012; it explains the fundamental operating principle of vortex tubes. The search for this explanation began in 1933 when the vortex tube was discovered and continued for more than 80 years.So I don't feel bad that I'd never heard of it and had no idea how it worked. And I'll admit when I read the explanation that I still only have a vague notion of how it works.
Why did I discover it now? We have robotic machines that work in agricultural environments. Those machines have computers. We use computers and systems that can withstand up to about 105 (Fahrenheit). 99.8% of the time, the ambient temperature is below that. Unfortunately, 0.2% of the time, it gets hotter than that but the crops still need to be tended to and the machines fail and even die if they're run at a temperature hotter than 105. Yet for 0.2% of the time, it's expensive, bulky, and makes the system less robust due to complexity to add cooling via air conditioning to every single computer cabinet.
On the other hand, putting a vortex tube in each system isn't expensive, bulky, or complex. On those days when it's really hot, the grower can just attach an air supply from a compressor to the vortex tube and voila!, they can run our systems even when it's ridiculously hot. Most growers have compressors available, but even if they don't, it's straightforward to rent one on short notice. Problem solved!