Dual Evap Rotary by the Mole

[Gray Mole]

Well I could either sit on my butt and cry about running out of R23, or I could find something to do with my time...

I decided that since I was going to rework the High stage on my rotary cascade, I'd just pull what I needed to test out how it performs on a dual evap. I'll let you be the judge

I'ts just straight copper pipe, and a couple of old Mach2 evaps I had kicking around from mods. I figured I'd be using a pair of chilly's heads if I thought it was a decent project, and I think I'm gonna have to start saving

Details...

3/4HP Carrier/Mitsubishi compressor Rotary

4 row 12" by 6" condensor with 2 240v 65cfm fans

KMP solid core filter

Custom 7/8" pipe brazed for dual suction

3m captube .031" on each evap

2 Mach2 stock evap heads

3/8" solid suction

1/4" discharge with small anti-vibration coil

R290 for testing, and might get a 404a charge for further testing later

I'd definitely need to run flexi's for the evap's. The vibrate quite a bit with the rotary, whereas you might get away with solid lines on a smaller smoother compressor, not this one. I'ts just a test and changes will be made if it ends up being made into a working kit for someone.



Don't they look happy



That's the idea. I'ts not bad for size either, about 13" wide and 14" tall or so. Could fit into a gutted MM or YY case with ease I think. Don't know if a Twi-7 or whatever the small MM case is would fit the bill, but it's possible that it might, would need the dimensions.









Anyways, that's the overview. Not much room in my little shop with what's left of the latest cascade in the way, but I wanted to get this ready tonight for some loadtesting tomorrow, and I'll get all that posted.

Pressures were running 150psi High, and 5-6inHG Low. I got around -47c on each evap quite easy, and that's with pretty much Zero insulation. I need to lap the evaps tomorrow, and I'll get the 270w loadtester out and strap them on as a pair. With 3m of .031" cap on each, I'm thinking that each head should have a max capacity of 160+ watts each anyways the way I'll be tuning them so it should hold that load easily I hope with the power of the rotary behind it. We'll see what temps they can hold.

If the loadtesting goes well, I may be putting together some of these in the New year, so I'm hoping it's a good test. I don't expect 290 to give great load results, but if it goes well, it might get some 404a in there for more tests, as it's a much colder gas, and has a far better capacity for load.

Cheers guys, I'll update with some load results tomorrow.

Gray

 

[Master_G]

Nice little unit you have just stuck together, how loud is the rotary? Pretty good temps without insulation, but obviously load is where it counts, and capacity as well for dual evaps.

Good luck with the load tests tomorrow, great work as always Gray

G

 

[maverik-sg1]

The Machs use traditional piston compressors (recip style) what advantages does the rotary have.

That condensor looks awesome - should really help with load temps me thinks.

Mav

 

[fatty]

Again Grey very nice mate

Mav the rotary holds a better vaccum than a recip compressor they use a screw type arrangement

Master_G the rotary is a lot louder than a normal mach2 the kind of setup you would make with rotary compressors would be for benching not 24/7 usage also they do get very hot

 

[Gray Mole]

I was a little overcharged but I knew I was, I just wanted to get a good start and thought I'd just play with the charge afterward. It's just 290, so it's not really a big deal anyways.

For noise, it's funny. It's louder than the small quiet compressors, but the only thing I can compare it to is a Vapo compressor. I'ts almost exactly the same noise, like a fridge running, and just a little bit louder. Not much though, which is surprising. I don't know what Rotaries are quiet ones, but these aren't for a 'silent' system. The fans I used are fairly quiet though, so in a custom box with some sound dampener it would probably be a reasonable noise level. These compressors are designed to run hot, and they can run at 100c quite easily, as these do. The cutout is at 150c, so it's running quite well, at about 96c is what I measured the compressor at under load.

I didn't bother insulating the lines for the load testing, I just did a quick lapping to clean the heads up, and got the load resistor clamped on and insulated. I tested the resistor whilst frozen, and got 218 ohms out of it. With the 245v tested from the mains, that puts the total load on the heads at pretty much 275 watts shared between them. So assume 137.5 watts load on each head.

After the loadtester was on, I adjusted the charge down a little to get a decent temp, and maintain capacity. Pressures ended up at 150psi High, and about 1-2psi Low. After I shut the tester down, I ended up with about 130psi High, and 8-9inHG Low.



That's what it looked like under load. After I got the charge right, it was just frosting into the suction acumulator. I probably could have gone further, but the result was good enough for me where it ended up. besides, this way I'm sure I've got more capacity to spare and the compressor get's a little bit of extra cooling.



Head No.1



Head No.2

You can tell 'em apart, cos I only had a short Thermocouple handy for one head, so it was pulling a bit when I hooked up the Fluke to get pics

The balance is amazing on this thing. Load temps were virtually identical and that's what I was after. When it was built tho I made sure that the captube and the suction tubes were identical lengths.



Head one after getting to minimum temp



Head two at minimum temp

No that's not just a re-run They were exactly the same. Nice, and -51 was an amazing result on dual evap with R290 so I'm quite happy with it. I need to get two separate 150w testers to see what it would do for dual cpu, though almost 140w per head at -35 is quite good, especially with the evap's just being old Mach2 ones.

Really, the temps are very similar to single evap temps, so the project is a success. I may now insulate the lines, and give it a 404a charge and loadtest. I'd be interested to see it, cos 404a should bring the temps down, and also has about double the mass, so should bring those load temps down by a fair bit as well.

So obviously there'll be some proper dual evap goodness coming with some decent evap heads soon. I don't even need to change much of what I have here, as I can just pull the captubes, chop the lines, and put some flexi's and new evaps on there quite easily now.



That's all I have to say about that :$

Gray

 

[scorchio]

Looks good Grey i think a triple is just round rhe corner,i should have some results soon from my mach and can tell you it's benching at 3.6 with ease.

LOL i'm glad nobody brought it now a few more tweaks

 

[Gray Mole]

Very good news, We'll see how much more you can squeeze

Sometimes all it takes is even 10c colder to get past the wall, though I'm curious, what's it showing for load/idle temps on the mobo's sensor? I think you'd said it was getting up to 10c or so, does it show lower now?

Triple evap? Shhhh that's the next test but don't tell anyone

LOL I'm gonna throw basically the same kit together with 3 evaps, and make the length of the cpu suction about 8" longer, and go with 2.5m of captube. I have no idea what temps to expect, but if they're even reasonable and the thing actually works at all 8) it would be nice.

Then I'll put the 150w load on the cpu and the 275w load on the pair of gpu evaps and see whether it can handle the loads, and where the temps end up. Will have to add a pretty big accumulator along the suction line I think, but we'll see if the one that's already on the compressor makes it possible to charge heavy enough to do it.

Cheers

Gray

 

[boardy]

/drool Triple evap phase change, mmmmm tasty!

That looks sweet Gray, keep it up mate, your making the brits look great at phase aswell now

Scorchio is that FX rock solid stable @ 3.6Ghz now? If it is, I MAY hit my target of 3.7-8Ghz on mine OOOO Can't wait to get all the kit and get Kool160 going like it was planned!

Nice work!!

 

[Gray Mole]

Well it looks like I'm getting a few evaps after the holiday, so I'll be putting the dual evap unit together properly then.

I think I'll do an MDF box for it, and just paint it black.

Just curious though, as a dual evap GPU is the obvious choice. I was thinking of doing up a dual cpu unit, and a cpu/gpu unit as well if I can get enough evaps for it.

What do you guys think? As far as the actual use of it goes, I'm currently without any real hardware so I'd just be selling 'em off cheap-ish anyways, but I'm not sure what ppl are after in an ideal world. Would anyone really have a use for dual cpu evap? Would anyone actually use a cpu/gpu setup with the temps being as low as they would be, and condensation issues on the gpu being more dificult to control?

Anyways, won't be long after Xmas I'll put a dual gpu cooler together so hopefully the results are as good or better with some decent evaps

Gray

 

[scorchio]

Well you know where i am if you need some testing done .

 

[Gray Mole]

You know I might just take you up on that offer

It's funny, but the pleasure I get from making these things is all I'm after at the moment. I always wanted to make them before so that I could use them, but now it's just the fun of making them that does it for me.

I have a feeling one of these on a gpu setup, just like the test-bed was, would likely be about -45 or so with decent evaps and 404a on both heads, maybe colder. If it would hold -50 per head benching gpu's that would be awesome, but hard to say really. I'd really like to see it get used though. Would be really sweet.

Any thoughts on cpu/gpu or dual cpu? The cpu/gpu I know would be handy for some out there, but dual cpu seems like it wouldn't be a very common thing to be used.

I still haven't gotten around to doing up a 3 evap kit, but that's next to try out.

I don't know, but 3/4HP divided by 3 is 1/4HP per head, and that's actually more than a Vapo has. I'm starting to really wonder about it. I doubt that it works out that way, and there could be some of the power lost in translation, but if it were even close it should perform well if the evaps were balanced properly.

Hopefully I'll find time during this festive season to try that out, but we'll see. I don't know if the temps would be spectacular, but should be decent, and be good for cpu and dual gpu which would be very cool to see on someone's PC

Gray

 

[Gray Mole]

Now it's a Triple

Well I couldn't resist, and converted it into a triple.

I'll have to get some pics with the insulation stripped off, but I did get some load testing on 290 again, just so I knew where I stood, and what I need to do to make improvements.

For one, the fans aren't doing the job anymore. The thinner 65cfm 240v fans were ok with the dual, but with the extra pressure and heat aren't doing as well, so I'll be throwing some 90cfm fans on the condensor.

The balance isn't as good as it was on the gpu evaps now for some reason, but not too bad. About 2c under load which is OK I guess.

The split for the cpu suction is about 3 inches closer to the compressor than the GPU's to get the suction bias toward the CPU head.

Captube is still 3m per GPU head, and 2.5m CPU head, .031" All 3 heads are recycled Mach2 evaporators.

Load temps are CPU -25c GPU1 -26c GPU2 -24c

Load pressures are 180psi High, and 9psi Low

Load testers are 150w CPU and 275w GPU shared

No load temps are CPU -42c GPU1 -40 GPU2 -39

No load pressures are 2psi Low and 145psi High

I really need a 4 channel temp meter, as swapping the Fluke over is getting to be a pain, but really for a triple evap, with that high a load, is giving somewhat reasonable temps. Total load is around 425w with both testers on, so I'm pretty happy with the overall result. I didn't think the temps would be amazing, but around -25 on each head under load, and the load being a bit higher than I would expect even with vmodded Graphix, gives some pretty good food for thought.

I really like these Rotaries.

I've still got a decent frostback, about halfway through the suction accumulator under load. I don't really want to back off too much, as I'm not 100% sure yet how far I'm frosting on each suction until I measure the superheat on each one.

I still haven't decided whether I'll make a triple for real, or just some duals from the Rotaries I've got here, but we'll see if someone actually wants one. 8)

I'll start a new thread with this info, and some pics of how it's put together tomorrow.