Well, I have frost....

[RussC]

I can't post pics right now, I'll try this evening. What a pain in the butt this was to get here. The brazing stuff has been kinda dinky, and getting all the stuff needed has been a pain. This project has nickel and dimed me too death also

Anyway, since my web site is full, Ill have to re-arrange some stuff to get the pics up. Beyond that, what sites are we using to post pics here?

OK,
Here are the pics....
Fist is the Oasis water cooler I picked up from Ebay for $35 w/shipping





Next, Stripped the system apart and used a piece of it as my base, I used the torch to braze the bottom piece togerther. then made a bracket to mount the fan...




Next, mount the compressor and hook up some of the copper tubbing...




This is the container I purchased at Target for $5, this will be the resevior. I'm using some hose barb to MPT3/8 for the water lines. These will get glued in later....




Here it is all brazed up and charged with R134a and cooling nicely...








And stopped at -23C.


I believe there is still an issue as my pressures are a little too low. I tried filling some more, but that didn't seem to help much. I believe I may have a restriction..that would not supprise me. If thats the case, I will redo the condensor and add a larger filter/drier. After that, it's pump, insulation and hookup to the head, so more later....

Thanks,
RussC

[k0nsl]

You can use putfile.com and imageshack.com for storing images, etc.

-k0nsl

[RussC]

Adjusted the refrigerant for no load a little, got -30c I wasn't aware that R134a would go that low. After ~20 minutes, it went down to -28c.



Started the resevor insulation..



Tomorrow is the wiring(fan control, temp control and power switch) and water lines with the cpu head. Plus more insulation.

RussC

[Marvin]

looks great, but why didnt you put the condenser in the right position ?
congrats..

[RussC]

Well,
I blew it, really
I didn't know it shouldv'e gone in 90deg rotated. Im going with it the way it is, since it's already there. So far I'm not sure if it changes the cooling

RussC

looks great, but why didnt you put the condenser in the right position ?
congrats..

[RussC]

Got the rig wired up....I did a couple of things.

Pics first:




I used the thermostat that came with the water fountain and wired it in with the switch(DTDP). As I see it, I like the idea of not having to run the chiller full tilt all the time. So I can use this thermostat to have the coolant be in the range of the thermostat. That way I can save money on power and run it 24/7.






Also, I used a light dimmer switch to control fan speed. I though this will save on my ears as well as a little power. I looked at the fan speed controllers, but felt I didn't need that as this fan is only 18W. There was also a in-line fuse. But I removed it as I had no fuses big enough. I'll have to get some 10A tomorrow and install it again.

And lastly, I found an issue with fan speed control. The compressor wont turn on if the fan load is not there also. Oppps, so when the unit is turned on, the fan speed has to be up almost on high for the compressor to start. Then it can be turned down if I want to.

RussC

[zightx]

Nice.

[cronic]

looks great i like the idea of a temp control. i think i will have to intergrate one on the chiller i am worjking on. looks great

[HelloIDistance]

Nice system, I like the temperature control idea! And if you don't mind me asking how much altogether did that cost?

[RussC]

For the most part, cheap, as water chillers go, although the thing is nickel and diming me to death now. Id say I got ~$250 into it, and that includes the new pump I just got(185ghp) from Home Depot. The key was the fountain for $35. Also includes the torch(oxy/MAPP), brazing rods and the like.

RussC

Nice system, I like the temperature control idea! And if you don't mind me asking how much altogether did that cost?

[jinu117]

The way you have condenser is not the best way. It might show uneven load condition and fluctuating temperature. What you are trying to do with above configuration is that as gas gets colder and turns into liquid, you will have many vertical hoops that liquid will have to work against gravity... which isn't too good. Thankfully high discharge pressure moves them along usually but it will just not work as good as otherwise. Another thing to consider is how would oil travel through condenser with such configuration.

[RussC]

right,
I know about the condenser position. I believe it wont hurt the system badly? As far as the oil, I thought that the refrigerant carries the oil, whether in a gas or liquid state? As you say, under high pressure, it should be able to clean out the condensor enough that refrigerant/oil will be carried throughout the system adequately.

Im going forward with the system as is and do some load testing. If I'm not satisfied with the cooling, then I'll tear the system down and re-do the condenser

RussC

The way you have condenser is not the best way. It might show uneven load condition and fluctuating temperature. What you are trying to do with above configuration is that as gas gets colder and turns into liquid, you will have many vertical hoops that liquid will have to work against gravity... which isn't too good. Thankfully high discharge pressure moves them along usually but it will just not work as good as otherwise. Another thing to consider is how would oil travel through condenser with such configuration.

[RussC]

OK,
Made the evap changes, rotated it 90deg so it has gravity flow down: pics



Also, I added another flare fitting to the suction side of compressor, now its completely servicable, huuuu removable:


And, my vacum pump, crude and old, but still works pretty well. Pumping the system down tonight, see if it holds vac, then fill and test tomorrow....


RussC

[wdrzal]

I can't see from pic's do you have the liquid line to the filter/capillary comming out of the BOTTOM of the condensor. The high side line from compressor should go to the top of the condensor.

Looking Great, keep up the good work.

[Gray Mole]

You're never gonna get the best results from that system if you don't move the condensor. You're refrigerant flow is gonna be pants, and oil can gather in the lines of it.

I'ts gotta be top to bottom. If it were a coil desuperheater and it was sideways it'd be different, cos they're not so tall, but that's just no good.

It'll take you an hour tops to put the condensor right, I strongly recommend it. You'll have to rework the shroud and fan mount, but I'm sure it's not that big a deal.

Otherwise, nice work on 134a mate

I'm working on a chiller for a friend of mine at the moment. I hope my results are as good as yours.

Gray

[RussC]

Sorry,
The pictures aren't that great, and mis-leading. Yes, the high side from the compressor goes to the top of the condenser. The condenser coils now run from top to bottom horizontaly. The bottom of the condenser(the liquid side) runs to the top of the system into the filter/drier. I added 1/4" copper tube to the high side so the length of the suction/liquid sides are equal. Im runing 6' of 0.031 cap tube. I may have to adjust this.

The system holds vac fine. Will charge later and test. I'll post more pics later that give a btter view of the condenser set up.

RussC

You're never gonna get the best results from that system if you don't move the condensor. You're refrigerant flow is gonna be pants, and oil can gather in the lines of it.

I'ts gotta be top to bottom. If it were a coil desuperheater and it was sideways it'd be different, cos they're not so tall, but that's just no good.

It'll take you an hour tops to put the condensor right, I strongly recommend it. You'll have to rework the shroud and fan mount, but I'm sure it's not that big a deal.

Otherwise, nice work on 134a mate

I'm working on a chiller for a friend of mine at the moment. I hope my results are as good as yours.

Gray

[RussC]

OK,
Heres the pic of the condenser. The high side leaves the compressor, goes into the top of the condenser, exits at the bottom. Then it wraps up and into a coil for equalization, into the filter/drier then cap tube into the resivoir.


Heres a pic of the system with no-load running..


And after 15mins, -24degC...


The temp was still dropping by ~0.1degC per minute. Not sure where it've stopped...But still not bad for a R134a system. Not sure how low a R134a system will go absolute?

RussC

[RussC]

OK,
I got the loadtester made. Used 2 50W resistors screwed to a 250W 92ohm power resister. Bought these at the surplus store for $9 total. Drilled and screwed the 2 50W to the large 250W unit...



I had to polish the top alot to get good contact with the cpu block. I tried with just the surface the 250W came with but it would overheat badly. It obviously had a very bad thermal conductivity(degC/watt). After some 1000grit, then 1200grit and finally some buffer wheel action, it was nice and smooth. Also used thermal compond on the resistors and cpu block.

System running..


So plugged in and set the resitance to equal 80W. With the ~35W of pump in the resivior, ~105W total. Heres the temp after 45 minutes..



Im really happy with the system so far...-18c with a 105W load. And I think Im under charged. Again, not bad for a R134a system

Ill be uping the load in a day or so to see what it can do @150W external.

RussC

[RussC]

Well, after the meldown, decided on a Swifttech 6002. Not sure the pump I have is enough, but I thought it was the best compromise for simplicity, efficiency and cost.

I also insulated the load tester a bit. Its 94ohm, so with the pump and the voltage, total load is 180W.



A pic of the full sys loaded @ 180W and R134a


I had some Freeze12 lieing around, so I thought Id see if it was any better. Im too cheap to buy a can tap, or the $16 3/16 flare pierce valve. I had a R12 can tap lying around, so I put it to use, nice and getto...
<a href="http://img354.imageshack.us/my.php?image=gettocantap11vr.jpg" target="_blank"><img src="http://img354.imageshack.us/img354/1044/gettocantap11vr.th.jpg" border="0" /></a>



So, the temps so far have been pretty good for the system Ive built. But....here are the pressures for R134a. I get the best temps with 134, not the Freeze12..I don't think Im supprised there.


RussC

[gkiing]

Those old lab-style vacuum pumps work great.. most will pull down to 15 microns or less (with an oil change). If you can't get proper refrigerant other than r134a aka "air in a can" you should just use bbq propane, it works really well.

[SexyMF]

Don't overestimate that pump heatload. It does use most of it's energy to shift water. Only a small portion is heat.

[RussC]

Yup,
Thats what I just did a couple hours ago. When to the rental supply and filled my LP tank. Purchased a LP tank to 1/4 MPT adapter and a 1/4 MFL fitting at Orchard. Filled nicely As a point, Porpane is filled on the low side as gas, right? Not on the high side as liquid, like the R40xa?

It would appear that Im getting ~6C cooler with BBQ propane over R134a. Ill need to do some more testing to make sure, as my load is not correct. Post some pics later. I need to get a better heat loader though, and a better mounting system for it. Thats my next project tomorrow. The plastic tie wraps are stretching over time and not making good contact with the loader

As a point, what pressures should I be running with propane. So far Im getting 155psi after the condenser, 8psi at compressor.

RussC

Those old lab-style vacuum pumps work great.. most will pull down to 15 microns or less (with an oil change). If you can't get proper refrigerant other than r134a aka "air in a can" you should just use bbq propane, it works really well.

[RussC]

What? The motor uses electrical energy. This energy is changed to motion. Whats the efficiency of that process? Whats left is heat. My pump is ~40W. I was using 30W as a heat load from it for my calculations. Is that too high?

RussC

Don't overestimate that pump heatload. It does use most of it's energy to shift water. Only a small portion is heat.

[SexyMF]

Using propane for torches (not the butane/propane mix that is LPG) I run 15/200psi.

[RussC]

What length cap tube for Propane. Im running 58" of 0.031". Should I use more or less?

Thanks,
RussC

Using propane for torches (not the butane/propane mix that is LPG) I run 15/200psi.