# Unusual project idea that nobody seems to do



## spaceman_spiff (Oct 21, 2014)

How come nobody has a made a miniature refrigerant closed loop system? Imagine the possibilities! A very effective and tiny battery powered drink cooler that blows the socks off of thermoelectric coolers and has all kinds of awesome mechanical and electrical components. 

If you dont completely understand how your typical compressor based refrigerant system works, like in your fridge or your car AC, think of it like this:

You know those cans of compressed air? Well alot of them are actually Freon. If you point them upside down you can spray liquid freon out which has some very low boiling point, something like -50F.

And it basically instantaneously freezes whatever you spray it on.

Thats exactly how closed loop refrigerant systems work. Well basically anyway. The key difference is that they are contained so the Freon doesnt just blow away in the wind and disappear.  You need a little heat exchanger to dump the heat to the outside world and you need something to act as a metering device, like an orifice. 

A simple one could be an evaporator with a piston attached and a certain amount of freon inside. The freon boils, cooling the evaporator. At some point, all the heat the freon is going to absorb has been absorbed, and you can determine that via pressure and temperature. At that point, you use the piston to increase the pressure in the evaporator and force the heat to be pumped out backwards through the evaporator into the outside world. Repeat. 

Or you could literally make a miniature replica of a closed loop modern AC system..including all the bells and whistles like a miniature compressor (copy an automotive one with reed valves and pistons), an orifice for metering, and mini evaporators and compressors. 

Seems like the possibilities are endless. Plus you can end up with a useful device, and there are some interesting mechanical engineering aspects to figure out.


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## Rbeckett (Oct 21, 2014)

Great idea, one of the fellow did one a long time ago But he has moved on to greener pastures and took all of his pics and threads with him.  

Bob


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## bosephus (Oct 21, 2014)

Ahh .. ice .. without it we are savages . 

You should read the mesquito coast


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## gredpe3 (Oct 22, 2014)

spaceman_spiff said:


> How come nobody has a made a miniature refrigerant closed loop system? Imagine the possibilities! A very effective and tiny battery powered drink cooler that blows the socks off of thermoelectric coolers and has all kinds of awesome mechanical and electrical components.
> 
> If you dont completely understand how your typical compressor based refrigerant system works, like in your fridge or your car AC, think of it like this:
> 
> ...



Sounds as if you have it all planned out,when will you start on it and will it be a WIP thread?


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## countryguy (Oct 22, 2014)

... I think Hobbes jumped on the keyboard while Calvin, Ummm S.Spiff was grabbing a brew.  (yuck yuck).   My FAV cartoon!       Love the handle btw.    Welcome to the HM.  I really love it here.  I see small fridge setups like you describe often on the Govt. Liq. site if you are looking for parts and small systems.   Just FYI.       Keep the bubble side up and the flame to the rear Spiff.     GC out.


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## chuckorlando (Oct 22, 2014)

I admittedly dont know nothing about this. But you got my interest with A/C ahahaha Any way you could scrounge up some pics of the things your talking about and how they would used? Or a link I could check out for my self?


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## spaceman_spiff (Oct 22, 2014)

gredpe3 said:


> Sounds as if you have it all planned out,when will you start on it and will it be a WIP thread?



I wish..but at this point anything I do in the machine shop as to have some kind of strong commercial component or at least be directly related to increasing machining capabilities..I cant justify working on a purely hobby related project like this..


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## spaceman_spiff (Oct 22, 2014)

chuckorlando said:


> I admittedly dont know nothing about this. But you got my interest with A/C ahahaha Any way you could scrounge up some pics of the things your talking about and how they would used? Or a link I could check out for my self?



thats the thing there arent any miniature ones I know about..and by mini I mean like an entire closed loop system that fits in a lunchbox

fridges, HVAC, car AC..they are all the same, just different sized parts..

there are also other refrigeration methods that dont use a compressor, such as the Ammonia based ones which use heat to make the cycle work...

lots of fun to be had here..plus if you somehow make the whole thing out of a transparent material you could watch the action

and you could have an electronic gizmo indicate efficiencies and temperatures

its a shmorgasborg of goodies!!


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