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View Full Version : DIY Refrigerant Recovery Machine!



XeonStrikeForce
01-01-07, 12:37 AM
Well I was bored out of my skull and for some reason house cleaning wasn't going to cut it, So I figured I'd finish a project that I had procrastinated away for dam well 5 years! (Ya I'm a pro at putting things off :D )

So a brief over view: The main reason I decided to build one was to re-use old R-12 from fridges as there are plenty about, but my conscious killed that Idea I just can't murder our environment like that by allowing the gas to be put into another system, I'll let the HVAC guys take it to be destroyed (Thats what we do in BC any old R-12 is incinerated and destroyed) how ever during a recent move the guys killed my chiller, and I been getting more R-22 charged systems. With my chiller damaged and scoring some Ac's I figured about time to make a system to both recover it and mediocrey recondition it by removing oil and other such things from it.

The design concept: By using an old green propane tank as the intake separater it leaves plenty of space for it to suck in liquid, and any who do home brewing knows the idea of distillation it works the same for refrigerant! We boil the refrigerant off leaving the waste oil inside the tank to be disposed of. Using an oil sep on the compressors discharge we can prevent the compressor oil from getting back into the refrigerant being recovered, and by using a cap the refrigerant being recovered will all so cool the compressor!

So after recovering the refrigerant, I set it up so it sucks in liquid, distills it, then puts it back in the tank in a continuous cycle, Oh with a F/D in-between the tank and machine of course on the suction side.

Now for the picies!

XeonStrikeForce
01-01-07, 12:38 AM
More pics

So thats it for now till I start fixing my chiller.

I have vaced it out to 28.5" Hg and it sat at that for over night with out budging and it held 85PSI through the day so I think it is safe to say it is a tight system. It will be charged with POE oil and I'll be using a CO-082 F/D.

I recomend puting a strainer inbetween the outlet of the tank and intake of the suction port of the compressor to protect against any particals that may have found their way into the tank during fabrication, I didn't have one on hand, so said sod it, and built it any way.

XeonStrikeForce
01-01-07, 12:41 AM
For any here making their own, the key thing they must do is list out what, where, how., IE: the type of refrigerants they expect to come accross, where in the system will they be breaking into the lines, or the terrain it will have to survive, and how do they wish to accomplish this.

My portable one is going to be powered by two 7Ah Gell cells wired in perallel feeding a 300 Watt inverter running a 240Watt compressor for a portable recovery machine, this unit can take AC if availible or run of a vehicle battery if availible, and will have a discharge oil sep only to gurentee no oil is leaving the compressor (Well as much as one can) and I may put a oil level indicater inside the compressor!

See how it answeres the three importand W's? then Oil compatibility, find the oil that will be compatible with the greatest number of refrigerants on your target list, don; Repeat the oil compatibility list and make a second one for other ones.

XeonStrikeForce
01-01-07, 12:43 AM
Low temp compressors are the best as they have a habbit of being able to suck down nicely and tend to work at a higher pressur differance.

Second is small power usage is nice, easier on power bill and environment, so I look for mini-deep freeser compressors as usualy they range from 2~4 Amp.

I prefer to have the oil seps there to keep oil from going in or out of the compresser as wzrl said it is not needed despit how irrelivant it was to the design being showen, but for some one making one from scratch, He is indeed correct the intake oil sep is optional if you wont be using it to recycle, IE it will only be a recovery machine with out a large intake oil sep (There is a way around that taking vapour from the first tank holding the old recovered refrigerant and transfering it to a new tank, it achives the same job but you need another whole new tank! the unit I built I just drain the old oil ).

Condencer, any small condencer will do the job, fan of your choice, I pulled a nice litle unit that is forced air off a mide range R-134a fridge (It is going in V2.0 of my recovery unit only I will replace the fan to a 12V type), so keep an eye out for fridges they some times are handly, easpecialy the oil coolers off some of them.

on the discharge side try to keep the tubing as tiny as possibly so it doesn't hold a high volume of refrigerant (I origionaly planned on using all 1/8 for the discharge side, next one it will be this) This should help avoid mixing internaly when you need to recover a dif,, refrigerant.

For your waste oil you can use a ball valve or packless valve, just make sure they can with stand the max expected pressure on the low side, I used schraders on the high side though ball valves would have been much better.

Plumbing: What ever works best yet reduces any stress points and isolates any vibration. The coils you see on my system serve no other perpose other then to reduce vibration from the compressor.

Oil: POE is the best choise for us as it is compatible with all most every refrigerant a SS-Chiller builder/Moder will come accross barring a select fiew, for the ones it is not simply build a second to handle the ones with an oil that will be compatible.

Special Notes:
1- For a unit made to recover small systems an oil cooler isn't required but wont hurt the thing far as long working life is concerned, you just don't want the oil too cool! Passive and small will be more then enough.

2- For systems where it will never draw from a receiver or doesn't need to be a self contained recycling unit as well, an intake oil sep is compleatly optional, If it will be a recycling unit as well you need a tank which can draw liquid & Vapour (& at this point you need a oil cooling method)

3- Lower power is good all round for every thing concerned! A small 2Amp low temp, will do the job, no need to use a 20Hp compressor to recover 12oz of refrigerant!!

(Sod it they don't pay me enough to be perfectly ontime)

4- Pluming the oil drain, Nifty thing called gravity will do the work for you! all ways find the lowest point in the low side to place the drain, and then try and keep a slant going all the way out to the exit point (don't rely souly on the pressure within the system!

5- Over engineering never hurts, they did it with voyager and look how long it lasted, kept transmiting till it got out of range! So go ahead and use oil seps strainers and such, but try to keep it on the low side! We want the high side to have as little volume as we can!

6- Check valves are a nice thing to prevent odd things from happening, if you got one I'd throw it on the oil out line, as last thing we want is to back flush it!

7- Think of it like a SS only open ended, out goes into a tank, in goes through a F/D and to a system, we want it to be low powered as we can reliably get away with.
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http://www.xtremesystems.org/forums/showthread.php?t=128218 < Origional thread

ashenfang
01-02-07, 08:37 PM
Looks good, except, here in the states I believe its illegal to capture, use, distribute or other wise handle certain refridgerants with out an EPA license. Looks good though!

XeonStrikeForce
01-03-07, 10:10 AM
Looks good, except, here in the states I believe its illegal to capture, use, distribute or other wise handle certain refridgerants with out an EPA license. Looks good though!

Here it is illegal to work on, make or buy even tools with out a full technitions liscance our system is far stricter then the US's So the only way to get tools for phase building is to make them or buy from ebay. Shipping is way to expensive for the shipping of recovery units.

As for refrigerant there is a loop hole for getting R-134a, R-152a and geting others is where the new toy comes in :D

untill 2014 I can't get any thing localy in country, with out a head ach, mabe after the first phase of the course I can buy stuff but thats not till 2008 <_< dosn't matter that I know the stuff better then the guy behind the dam store desk, no lisance they won't even listen!

Oh and it is illegal to buy use or sell ANY refrigerant with out full ticket, but yet they sell R-134a as an air duster go figure!

ashenfang
01-03-07, 09:07 PM
LOL, i guess it is more strict there. Doesn't make any sense here, they are more anal about you throwing out a fridge with coolant still in it more than they are about that old can of muratic acid you just threw out into the garbage :clap: oh well....still a nice set up you have there.

awillems
09-30-09, 07:11 AM
Hi Guys, I know this thread has been quiet for a while, but I am really interested in the DIY refrigeration recovery unit. I am not into overclocking, but rather into refrigeration and Air-conditioning. The commercial recovery units are incredibly expensive, and what I have seen on this page seems a lot more of an attractive option for me.

Thus - Is there any new progress on the plans and design of recovery equipment as featured on this thread? Regards, Abrie.

Dr Doright
08-27-11, 03:40 PM
I'm attempting to make my own refrigerant recovery machine,anyone willing to offer more insights..?