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Author: Subject: Small fridge (1.5-3 cu ft) compressor/cooling system - anyone know about these?
RogueRose
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[*] posted on 1-6-2018 at 22:48
Small fridge (1.5-3 cu ft) compressor/cooling system - anyone know about these?


I've been trying to find out how these mini fridges work. I'm looking for basically the smallest fridges that use a compressor and work either with 110/220 or 12v (ideally 12v). I've looked for the parts lists for some of these models but most of the parts sites just list the unit as they are probably less expensive to just replace.

What I'm looking for his a very small high PSI compressor and I am guessing that these fridge compressors are capable of a fairly high PSI similar to their larger "cousins" that are used in standard fridges or AC units. I'd like to get a minimum of 200 PSI but ideally something like 400 PSI would be ideal for the application. Flow does not need to be much as it is just used to fill a resevoir that is rarely depleted, so if it took 10-15 mins to fill the small resevoir, that wouldn't be an issue.

I have a few 12v tire inflators, some better quality than others, and one is rated at max 200psi but I have a little bit of difficulty believing this as it is basically the same as my 125 psi unit but is built a little better, so I guess it may be possible.

Now I was wondering if I could replace the motor on the 200psi unit with a motor from a power drill, an old 12 or 20v dewalt which has a motor much more powerful & better quality than the small compressor - the problem is getting the correct gear for the drill motor drive shaft and possibly mounting the motor on the compressor. The motor is about 2.5x the physical size of the compressor motor but the way it mounts it shouldn't be a problem the way it connects to the compressor drive shaft.

IDK if adding a stronger motor would increase the PSI or if it would just increase the flow rate at the higher PSI where the smaller motor would be under more strain. I would think that the compressor cylinder/seals and valves would be the limiting factor in increasing the max PSI output.

I know that a car's AC system uses a compressor and I'm wondering if it would be possible to add an additional compressor (with adequate PSI rating) to a car which could be used for air. I know some cars have air (bag/piston) suspensions but IDK how they really work. This method seems maybe more difficult and expensive than what I outlined above, but IDK a lot about adding something to the engine pulley system.



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Ubya
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[*] posted on 2-6-2018 at 01:36
too many questions at once


1)
Quote:

I've been trying to find out how these mini fridges work. I'm looking for basically the smallest fridges that use a compressor and work either with 110/220 or 12v (ideally 12v). I've looked for the parts lists for some of these models but most of the parts sites just list the unit as they are probably less expensive to just replace.

you can just search on ebay or aliexpress, there are many 120/220v compressors and also mini 12v DC compressors.

Quote:

What I'm looking for his a very small high PSI compressor and I am guessing that these fridge compressors are capable of a fairly high PSI similar to their larger "cousins" that are used in standard fridges or AC units


if they use the same refrigerant they use the same pressure, just a different (smaller) flow. pressures can reach 500 psi so they are good for your project, but remember that some compressors use polyester oil (POE oil), moisture will turn it acidic and destroy the compressor, so make sure the compressor you chose use mineral oil or any other kind of oil non moisture sensitive.

2)

Quote:

Now I was wondering if I could replace the motor on the 200psi unit with a motor from a power drill, an old 12 or 20v dewalt which has a motor much more powerful & better quality than the small compressor - the problem is getting the correct gear for the drill motor drive shaft and possibly mounting the motor on the compressor.
Quote:
The motor is about 2.5x the physical size of the compressor motor but the way it mounts it shouldn't be a problem the way it connects to the compressor drive shaft.


so is it a problem or not the way they connect?
anyway, if your motor stalls at the maximum pressure, changing the motor with the power drill will help, but if the maximum pressure is related to the max working pressure of the check valves a bigger motor won't help

3)

Quote:

I know that a car's AC system uses a compressor and I'm wondering if it would be possible to add an additional compressor (with adequate PSI rating) to a car which could be used for air. I know some cars have air (bag/piston) suspensions but IDK how they really work. This method seems maybe more difficult and expensive than what I outlined above, but IDK a lot about adding something to the engine pulley system.


you wanted a small compressor, well a car ac system compressor is pretty bulky, and it hasn't a motor, so you would also need a bulky motor





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XeonTheMGPony
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[*] posted on 7-6-2018 at 15:51


What exactly to you want to know in direct terms, < Refer tech

12v recips can get to very high pressures but need to be started unloaded, and pressure removed on restart.

[Edited on 8-6-2018 by XeonTheMGPony]
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Herr Haber
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[*] posted on 8-6-2018 at 03:18


Maybe check the hotels near you if they have a broken mini-fridge ? Or since it's summer, many AC technicians will be servicing air conditioners. My bet is that it should be easy to find parts / whole units at this time of the year.
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