? if I build a direct die phase change setup. Can I hire someone to charge it?

[JNav89GT]

I don't want to use propane, and I'm not sure that R134a would be enough cooling.

I would want -40C temps at least. Maybe I am wrong but I doubt R134 could get me there. I would be running lets say a 2800+ @ hopefully near 3ghz at 2.0-2.05v so assume alot of W of radiating heat.

If R134A could get me there then great I am going that route as I can buy and charge that system. However, I am thinking I may need R12 or better in which case if I build this system and I bring it to a fridge shop. After the tech weenies stop laughing at me will they be able to charge it or are there some laws against them charging a frakenstein refridge unit.

[|PuNiSh3R|]

um.. R12 you won't get and don't want.. -40C is hard.. you want -40C at full load.. that's not gonna be easy.. you are either going to need a monster of a compressor.. like 1/2HP or higher.. and a good refrigerant like, R503, R13B1, R170, R50..

That is just a small list of refrigerants that get well below -40C boiling temp.. I don't know how good some of them are though.. I know R50 is good.. but I believe that's methane.. so you will need a cascade system to even dream of making it a viable refrigerant.. Um.. R503.. I think their is an R508.. that works well.. idk.. anyway.. you will need to get the system charged with a refrigerant they have at their shop.. which is gonna be, R22, R134a, R404a, um.. and some DuPont §§§§.. some stuff like H66 etc.. They won't have anything in stock that will give you your -40C like a miracle from jesus.. So .. unless you want to buy them a full (20lb) tank of refrigerant.. you are out of luck.. as far as I see.

Although one solution would be doing a dual compressor system.. That would allow you to run a vacuum in the evap all the time.. So if you run.. say.. R22 which would be an excellent and cheap refrigerant for this application.. You'd get -42C at 0PSI on the low side.. put the low side in oh.. 10.. 15" of vacuum from a dual compressor setup.. and you will be running around -55C maybe colder.. depends on your condenser(s).. etc..

[JNav89GT]

thanks for response. Ok let me ammend my wish list then. I would want say -10C to -20C at load considering a big heat load is this possible?

[|PuNiSh3R|]

that is possible with the right size compressor and R-134a.. either way dude.. go with propane.. it will save you so much money and offer you damn cold temps.. The phase change systems I build give -38F evap block temps at full load.. I use either propane or R22.. and most of the time I use propane..

[aenigma]

Uhm most of the refrigerants you listed are du-pont, considering du-pont is a monopoly here.
R50 and R170, methane and ethane.-161c and -80c and you would need too much pressure to condense them.R508 is also a low stage cascade refrigerant.You don't need that to get -40c.

R12 R22 R404 and R290(propane) will get sub -40c loaded evaporator temps(not cpu) if you know how to build a system.
-20c loaded cpu temps will be easy, as long as your block makes good contact and whatnot.

[|PuNiSh3R|]

heh.. yea true.. i don't know much refrigerant information.. either way.. you could do -20C loaded with 134a if you did things right and had a good compressor..

[JNav89GT]

well I have a r12/22 don't know which compresser off of the AC unit I was converting from that window AC unit. However, it needs some capacitor thing to bump voltage to 145v to start as it won't start at 115v as I assume most compressers run off of. Plus it's old and I'm sure weak. I would just as soon spend a bit if $ to make sure what I build will actually work and cool as much as I want

thanks guys

[aenigma]

That compressor will work good, it is an R22 compressor.It does need a start/run capacitor, all compressors do.
The compressor is probably at least 1/2hp.And it is not weak.Older compressors are usually your best bet, up to a certain point that it.You are underestimating this compressor

First a/c I actually put an evap on and did real basic stuff to, was a 1/2hp.I just put a spiral of evap on it, and didn't change anything else.Got I think -40c liquid temps.Now if you went direct die with it, well you get the point.
Right now I am using 2 R22 a/c compressors.Most of the stuff I make uses a/c compressors...

[JNav89GT]

could I convert it to R134A easily if I used that AC compressor. I don't think I could capture the freon in the system currently so i would either have to use propane(which I'm not excited about) or R134A.

thanks

It would be kinda nice to reuse that compressor b/c then my capp tube length is calculated.

[aenigma]

No your cap tube is not calculated.It is calculated to remove x ammount of btu @ 0-6c evap temp.Way too big....
You could set it up for R134a if you drain the oil, but that would be a huge waste and you would need to be shot.R134a is a joke.I don't see what your problem with using propane is?Because flammability is not as big of a problem as most people think.Most people just jump to conclusions because they haven't the slightest clue about it....

[|PuNiSh3R|]

FU AENIGMA! PROPANE BURNS IN OUR GRILLS! IT MAKES A BANG WHEN YOU LIGHT YOUR GRILL! YOUR LYING!! PROPANE IS SO DEADLY!!! roflmao.. yea ok so propane is deadly.. if you are like me and take your lit torch around it while letting the vapor out.. it's not really "deadly" but it makes some awesome fireballs.. specially if you put your lit torch on the ground like.. 5ft away from you and you let some vapor propane out across the floor.. man this huge WOOOOOF! fire ball flys across your floor.. it's so awesome.. just don't do like me and stand in the middle of it! lol

[aenigma]

hahaha I hear ya man.
I did something real stupid awhile back after building a 3/4hp condensing unit using my maze3 with lucite top.Well I decided to put a heat load to the LEAKING block with a torch.
I guess I was looking for a big fireball.Well I got one...

[|PuNiSh3R|]

haha.. yea i was putting a heatload on my evap block and i was letting propane outta the system at the same time.. letting it out of the high side is fine.. letting it out of low side = fffiirree!

Propane doesn't explode unless it's accumulated.. like if you opened the valve to your grill n kept the lid down for like 30 seconds.. then lit it.. sure it's going to go BOOM! but that is in an enclosed area where it can accumulate.. otherwise it just burns off quickly

[JNav89GT]

my wife would kick my ass if she knew I put propane in my phase change setup.

Ok, you guys are now talking me into canabalizing my window AC unit.

What do you recommend for a condeser though as the window AC unit is kinda too big. I would rather not pull a hack and cap on the one I have. Is there a smaller one I can just buy.

Also, I may need to buy some of those brazing rods off you punisher.

could you email me at jcook84889@insightbb.com

I need to talk more in depth to make sure this isn't beyond my mechanical abilities.

[JNav89GT]

what do you guys think of this compressor
http://www.panasonic.com/industrial/...s30c50kau6.pdf

[|PuNiSh3R|]

I wouldn't waste my money on a new compressor.. specially since you are a beginner.. totally not worth it. The chance that you might kill it or F it up behind your repair means.

[|PuNiSh3R|]

not to mention it's only 238btu/h. You need 1,500-2,000BTU hour if you want to see any temps.. You would be overloading that compressor .. You might as well buy a vapochill if you want a system with an overloaded compressor and 0C temps.

[JNav89GT]

lol true

that's why I asked :p

[aenigma]

Ok I didn't see that this thread got updated...
Don't worry about breaking the compressor, that won't happen anytime soon...Punisher has done it, but well, hes punisher. :p

Yeah you can buy a condenser online and get ripped off, rparts sells little ones for about 60 bucks.Oh and you can get brazing rods from Ace hardware, or any place like aces...

[|PuNiSh3R|]

Yea, but you pay 3 dollars for 3 rods.. it's a rip..

I wasn't talking about KILLING it per say.. just that it wasn't worth buying a new one since he's new to phase change and he COULD do it.. he could drop the thing.. or who knows what.. You have to put oil in them.. he might screw that up.. and kill it.. ya never know.

[aenigma]

They come charged with oil...
I do agree new compressor are a waste of money, I like the quality of old compressor.They are built like tanks.

I forgot what I pay at ace, but it is not 3 dollars for 3 rods.I pay 10 bucks, but I forgot how many rods there are....

[|PuNiSh3R|]

Um well I go to ace all the time and they don't sell §§§§ except the bernzomatic ones.. either way.. Not all new compressors come charged.. I don't think.. I looked at some and they said u had to put oil in upon receiving.. i think they were from Rparts....

[aenigma]

yeah well if you cant read that you have to add oil, then you deserve to ruin it

That is odd that your aces doesn't have them....

[|PuNiSh3R|]

eh lol.. I don't care.. I get them cheaper at the refrigeration store.