Things to build a liquid chiller..

[Paxi]

hi... i am interested in building a liquid chiller for my second rig, also to get some experience in this area and also just for fun ..
but i need some infos before..
Of course I need a compressor(maybe with R22 or R134a). an evapoator and now?
i have already informated me a bit but i would be very happy if someone could tell me exactly what i need to built a liquid chiller..
regards Blasna

[f00t]

a compressor, a condensor, an evaporator, some sort of reservoir (if your keeping it somple), refrgerant, oil, brazing rods, a good torch, insulation, guages, shraeder valves, a fan (to cool condensor), a drier/ filter, copper tubing, wood/ metal (to mount it on), vacuum pump, cooling fluid, thermometer device, patience.

whew

[Paxi]

thnx.. quite much stuff ;>

[f00t]

forgot cap tube

[unixxx]

And if you wanna be legal: a recovery tank as well.

[Lowvez]

is a vacuum pump absolutely necessary? and what is a recovery tank used for?!

[unixxx]

You use the recovery tank/cylinder to store the refrigerant you remove from the old A/C unit. You can reuse this refrigerant after you've converted the A/C unit to a chiller. Unfortunately I don't believe you can properly dispose of the recovered refrigerant in the US unless you're EPA certified. You need a vacuum pump to remove the air from the lines so that when you charge them with refrigerant they'll be free of air. Air in your lines greatly reduces your cooling capacity.

[Lowvez]

But, if i know someone who is an HVAC specialist and repairs these things for a living and he is going to charge it and deal with all that then i'm good to go right?!

[Stewie007]

You need to draw a vac to remove moisture and other condensable gases. Air is only a small part of the game.

[gclg2000]

Go talk to an A/C shop. If you want to save yourself a big headache. Don't fool around with cap tub. Get a TEV valve (~$60 or so) and let it do the load handle automatically. This will be especially usefull if you want to add a video card in the loop.

This will completely eliminate the headache of getting right sized cap tube and length. PLus with this valve you can adjust the super heat which in turn can help you adjust the temps. You could prob use a better gas like 404 to get the liquid down to -47 C or so then adjust the superheat knob to make it a little warmer if ya like.

Talk to an HVAC technician, i bet he would vaccum and chrage it for ya for next to nothing.

Maybe i'm going overboard, but the TXV valve is making my project much easier to manage heat load.

[Lowvez]

Go talk to an A/C shop. If you want to save yourself a big headache. Don't fool around with cap tub. Get a TEV valve (~$60 or so) and let it do the load handle automatically. This will be especially usefull if you want to add a video card in the loop.

This will completely eliminate the headache of getting right sized cap tube and length. PLus with this valve you can adjust the super heat which in turn can help you adjust the temps. You could prob use a better gas like 404 to get the liquid down to -47 C or so then adjust the superheat knob to make it a little warmer if ya like.

Talk to an HVAC technician, i bet he would vaccum and chrage it for ya for next to nothing.

Maybe i'm going overboard, but the TXV valve is making my project much easier to manage heat load.

My uncle is an HVAC tech...i'm sure he won't charge me! Plus he has R12 readily available.

[Stewie007]

Maybe i'm going overboard, but the TXV valve is making my project much easier to manage heat load.

TXVs are indeed the best solution. I got cap tube, but I'm really thinking about ditching it for a TXV. Externally balanced, that way it doesn't have to be parallel to the evap unit.

The initial cost is worth it, and you don't need to worry about brazing it shut. However, you DO need to worry about burning up the diaphragm while brazing. You can remove them though, usually by disassembling the valve. I do it all the time at work on the overload solenoid valves, it makes the job a heck of alot easier than wrapping it in a cold towel, because that doesn't really work for .

The only thing you have to worry about with a TXV is what they call, TXV “hunting.” To understand this you need to look up how a TXV works. Its tough to explain. Basically, in such an example the bulb senses the superheat at the outlet, and adjusts according to the setting. The TXV will then react by opening the valve a bit or by constricting flow accordingly. The problem is, the fluid takes time, although finite, to reach the end of the evaporator, and the valve may overshoot, therefore causing it to "hunt" for a stable set point. For this application it may or may not matter.

But that's a heck of alot easier to cope with than having to reclaim cut and rebraze a capillary tube, let alone worry about brazing the cap tube shut. Easy as pie.

Edit: Oh, and not to mention if you mess up and cut your cap tube too short and have to go out and get more.

[wdrzal]

Stewies right,did I just say that ,if you are not going to do the charging yourself spending more on the tex valve is cheaper than getting some else to evacuate and charge the system over and over until you get the cap tube right. But doing it yourself is all the fun. It actully pays pretty well also. walt

[gclg2000]

Stewies right,did I just say that ,if you are not going to do the charging yourself spending more on the tex valve is cheaper than getting some else to evacuate and charge the system over and over until you get the cap tube right. But doing it yourself is all the fun. It actully pays pretty well also. walt

hey...i was right first...

But hopefully all 3 of us have convinced you to go w/ a TEV. Besides, get a flar fitting one, and when you mature past this chiller, you can use it on a cascade one day. "recycle it"

[wdrzal]

Go ahead whip me,I can take it ,that hurt my butts red

[FireDragon]

So are they TXV or TEV'S where can you get them? As I am making my chiller and I am using R404 I am hopping for temps around -40 so that TXV/TEV will be great for my project...so can that also be used in conjuction with something that turn the pump on and off like a thermistat unit so that once it gets to say -38 the system comes back on and pulls the water back down...my plain is to make a board with an LCD that tells res temp, evap temp, compressor temp, and maybe have an overheat fan on the compressor, and possible a fan control the condensor...alot of work but i can do it as a school progect...and get credit for it and maybe get all of the parts for free...but yeah that is my chiller plain...i am going to start a thread on it here soon...so that i can throw around ideas and such

[Stewie007]

Hey guys, this is a historic occaision where we, all three agree.

And BTW it is TXV, Thermostatic Expansion Valve. TEV works, but when you walk into the service store sayin that they'll look at you funny.

[wdrzal]

That would be a good project for someone to put a complete list of abbreviations used on this site. TEV means TXV I have seem them cataloged both ways: Thermal Expansion Valve.

Walt

[Stewie007]

Thermostatic.....

[gclg2000]

here

Thermostatic.....

Here man below is some help:

This is the valve i'm using (the TXV) It should be just right for what your wanting to do.

Parker C-AA-SW 1/4" inlet 1/2" outlet 1/8 - 1/2 Ton **Parker is brand name**

Here is a link to the picture of the box mine came in and here is what it looks like. It may be on backorder, it took 2 weeks for the shop to get mine in from the time i ordered it, so you may want to go ahead and get it moving.

Hope this helps out, PM if you need more help.

[Stewie007]

Personally I favor the External Equalizer

[wdrzal]

why? what charge are you going to use? walt

[Stewie007]

Well it just prevents pressure drop and coil starvation. Because when the pressure drops, the bulb pressure drops with the lowering temperature. It then loses its ability to open the valve and starves the coil.

With a balancing line, it will maximize efficiency. The outlet of the evaporator will now apply the proper force to the TXV to govern evaporator flow and pressure, instead of the outlet of the valve.

If your evaporator isn't very large, it won't really be neccessary. But the thing is, it doesn't hurt. It can only make it more effective.




Edited a Typo "Will Not apply" to "Will now apply".

[unixxx]

That would be a good project for someone to put a complete list of abbreviations used on this site. TEV means TXV I have seem them cataloged both ways: Thermal Expansion Valve.

Walt

Great idea. I just setup a wiki page for Phase Change acronyms here: http://www.fuzzymuzzle.com/compwiki/...hange_Acronyms Please feel free to add as many acronyms as you like to the list.