External A/C Chilled liquid cooler project

[Drewmeister]

Nice.. too bad you have to insulate it. Not sure what you're plans are for insulating the top, just make sure to leave a little inspection window to check for frost buildup. Maybe you can insulate the outside of the top and have a removable square that covers the window.

TG's idea is very ingenious and sounds great in theory. My concern would be getting adequate flow through the fins and maze of separators. That's going to be a pretty rough journey for the coolant. It will have to contend with the surface tension going through the fins on each pass, dead heading at each turn and eddy currents. If say there are four passes, that's nearly 8" of coil depth with very little head pressure. If you do try it then perhaps add turning vanes at each corner to help the flow along.

You could also just try the most simple approach first, see how it performs and go from there. I think I'd try the multi return point idea first. Both returns up high with holes/nozzles aimed at various angles to cover the whole evap. Pump inlets on the opposite side near the bottom.. one left, one right.

[Orthello77]

Removable square is what i thought for the viewing panel , i'll adhesive the insulation to some MDF and when you pull off the top MDF lid the inner square insulation will come out
allowing viewing.

Re TGs idea i had thought about joined half circles eg edge to edge half circles, that would route the fluid a bit better as there would be no corners. I was a bit worried about how the fluid would flow through it, i'm not sure it would level that fast at the outlet end.

Or like you say just multiple inlets / outlets which would channel inflow and outflow. That is also the most simple option to build i would expect too. One reservation i have about this idea is the pressure required to spay out in say 4 or so directions with any real pressure. The piping would need to be a few sizes smaller than the inlet i would say.

[technogiant]

Your pics look great...this is developing into a real nice build.

As regards your reservoir....Like Drew said, try the simplest first and see if you do have problems, it's easy to think too far ahead and solve problems that really aren't there or are so minor as to not be worth the extra work.

I don't think you're going to have a problem with the simple two compartment build tbh.

I don't think there is going to be uneven flow through the evap. As the evap is the main resistance to flow in the reservoir what will happen is that a slight pressure head of water will develop on the inlet side as compared to the exit chamber. That pressure head will act purely across the evap which is the biggest resistance and cause an even flow through the whole area of the evap irrespective of which direction it then takes to the exit tube. All I would say you have to be concerned about is that the inlet coolant mixes well in the inlet chamber so that the returning heat is distributed as evenly as possible to the evap, perhaps use a multi hole pipe or other method. I wouldn't worry about the exit tube, the fluid will just flow evenly to it.........just my opinion for what its worth.

But of course if possible a top to bottom forced flow through the evap is bound to be better if for no other reason than the fluid will be forced through a much longer cooling channel than simply going from one side to the other.

[Orthello77]

One thing i have been thinking about in all of this is the ability to clean the evapourater should that be needed. Putting a shroud around it sort of makes that hard. I may do a few water only fills and refills to make sure its a clean as possible before using the low temperature mix. If i can get it quite clean and use a filter on the pump then possibly shrouding the evapourater won't be an issue as it won't need cleaning long term.

Got to think of long term usablity !

I have two 4 way splitters, i bought them a while ago and never used them , i was thinking i use the 2 compartment idea i can use them as they have valve taps on each output. Its tempting as it would put them to some use , using stuff i already have is always tempting lol .. less cost.

Additional Comment:

Just a small update whilst waiting for insulation and other bits to arrive. I got out the jigsaw and grabbed some old 5mm acylic i had and started to make a lot of mess lol.

This is the mounting i'll use to hold the GTX 360 radiator into the chamber. Just a gravity cradle but it should do the job Nicely. The side with the smaller notch is to allow for piping.

[technogiant]

That looks nice and neat, should do the job admirably.

Have you considered doing a water only test and maybe adding some color/stain to the water so you can get some idea of how the flow and mixing is going?

[Orthello77]

Yeah i think i will do a few water only tests, i'm keen to do that just to wash out any contaminates also. If my insulation arrives before the weekend then i could have my water chiller nearly finished apart from the internal arrangement (depending on what i decide there) all done.

I have one more order coming from frozenCPU and just the insulation to come, everything else is pretty much been aquired. So just a waiting game now.

Additional Comment:

Insulation has arrived and for closed cell foam its really really dense. Its a polyethylene foam , 30 mm and its rated for use down to -70c apparently , hope it cuts nicely lol. Also getting the chambers frame made up this weekend also .. now i have got loads to do !!

[technogiant]

lol....and you were just wishing you had something to get on with.....now your inundated...lol

It's great your stuffs coming through...don't get so busy that you can't update us mind!

Additional Comment:

Where's Orthello gone? Has he fallen off the face of the earth? or is he just buried under insulation foam and acrylic?

lol.....hows it going mate.

[Orthello77]

lol inundated is the word for it.

I picked up the chambers shelf if you like today, basically a box with open top compartment with lid. Its made out of some sort of vaneered MDF that some customers of ours had lying around. I wanted it black looking so should be ideal. They used a CNC machine to get it pretty accurate so the chamber will fit in snugly with room for one outer layer of insulation.

Also i have added an additional layer of expoxy to all of the internal joins in the chamber just to add to its strength , it could be uneccessary but its just a bit of reassurance really. Cut the first panel out of the 30mm insulation and wow its easy to work with , much firmer than neoprene or aeroflex and therefore cuts better. It bends less however which doesn't worry me.

I'll have some photos up tommorrow i would think of the fully insulated internal chamber , also hoping to get the A/C mounted on the base if my brother shows up for the heavy lifting lol.

[technogiant]

Taking about strength and weight I had a near miss with my build. It's all mounted on a sheet of thick mdf on castors.

When I started I was certain this would be more that strong enough.

But as the build has proceeded the weight on that thing has grown and grown, the lid alone is very heavy and I noticed that mdf sheet was sagging in the middle right where the evap tubes go from the box to the compressor .......if that had gone it would have been the end of the news.

I've now put another square of 18mm mdf I had spare from the lid on 4 smaller castors and slid that under the middle section so its good now (the wife's idea love her).

I'm also quite concerned about the amount of clamping pressure you have to put on the lid to get a good seal, those webbing straps are so tight I can play them like a two string guitar.

Just hope the box is strong enough to cope with those forces long term, as I'm happy its not exchanging air I'll just leave it sealed for long periods of time so the desiccant can do its job. Just inspecting through the viewing window for signs of frost.

Having said that there's enough adhesive / sealant on those joints to sink a battleship and that clamping pressure is distributed evenly over the whole sealing surface...just another little worry I have....another unknown quantity...but it should be alright.

I must admit I'll be glad when its finished now, there's so many things to go wrong that have to be thought out first, and if you make an error and ruin it....well, all in all this has cost me £800 so far...that's a lot of money to get no return from.

Still hopefully today I'll get my dvi cable and be able to finish, should be here by Monday at the latest.

Do you know if it will be alright to run a fiber optic cable in the chamber, for one I was concerned the temp may affect it, and secondly are they solid or hollow fibres? don't want to let air in or out. I think they are made out of a solid plastic so shouldn't be a problem unless the cold makes the fiber brittle...just not sure.

[Orthello77]

Hey TG, just finished cutting the insulation for the chamber, just need to glue it in now.

Also mounted the A/C on the frame , was a 2 man job !! i'm lucky my brother is a huge guy as he was the one lifting the A/C while i held the evapourater and we just dropped it into place on top of the base / chillibin. More insulation to go on the chilli bin yet too.

I think my base should be ok, its 25mm treated ply. Seems very solid. Lucky you noticed the sag before the big snap !! Yeah lots of things can go wrong, like today when mounting the A/C with the insulation one of the incoming pipes to the evapourater is resting on the chilli box wall whereas it had clearance without the insulation. I'm not sure if i can make the notch wider without taking it all apart ... and thats a 2 man job. Might see if i can get a hacksaw clearance in there, if not i'll just pad it best i can.

[technogiant]

Looking good Orthello.....like you said previously....nothing ever goes completely to plan...just watch those pipes with that hack saw blade my friend.

I had a similar problem, I hadn't considered the extra height that the insulation box would have when it was sat in the acrylic box and the extra height the triple seals on the acrylic box gave it. Still was able to wangle that one by a some more packing under the ac unit.......it is almost impossible to think of everything.

On that note must run...Mr Postman has just delivered my dvi cable...now to finish up.....should be testing tomorrow.

[Orthello77]

Hey Guys, Another weekend down, some more progress, not as much as i would have liked though.

I widened the notch for the pipes coming into the chilli bin above to get the pipe off the side of the chillibin. You have no idea how hard that was when i had to widen it while the pipes are not even centremetres away lol. Imagine holding the blade of the hacksaw because you dont have room for the hacksaw !!

Fully insulated the chamber with base and side walls. The internal gasket is looking pretty good, one area where possibly its not 100 % but it was always going to be hard as it was 4 seperate pces of insulation that had to be exactly the right height. The adhesive was not forgiving , basically the momment the surfaces touched they were stuck together. Possibly silicon would have been better , more adjustable. Hindsight is always 20/20.

Also used a whole tube of liquid nails under the chillibin base !! don't think its moving any time soon lol.

Pic of the chamber , the internal walls although not a single piece gasket act as a combined gasket as i purposely made them taller than needed by 2-3 mm , been foam they compress in when the lid screws down.

[technogiant]

Fair play Orthello this is looking fantastic.....bet you can't wait to push that start button.

On that note I've pushed mine.....and I've got some problems....would appreciate if your able to take a look and offer any advice.

[Orthello77]

Thanks TG i see the overclocking gods are presenting a few more challenges to us mere mortals ! ..

I have replied with a few ideas .. hey at least you are testing !! i'm like two weeks away from those sorts of headaches :-(

Additional Comment:

I just updated my spreadsheet for costings / whats got to be done / aquired etc.

It looks like i have 95 % of everything i need to finish.
The cost is there , but its best forgotten ;-).
It also looks like i have an estimated 23 solid hours of work to do (atleast) lol .. oh well its good to know what the time frame is , seems like its taking forever !!

[technogiant]

Keep chipping away at it, it will be worth it in the end, recon your temps are going to be fantastic with direct water cooling from the res.

[Orthello77]

Hey TG, did about 5 hrs last night .. the house is pretty much a workshop atm lol .. understanding wife !!

I did the outer insulation on the chamber theres 70mm now on the base and sides. The roof will have a shade less that it. I'd allowed about 3 hrs for that, it took more like 5 hrs. So i guess my 23 hours is more like 40 hours lol. Anyway its progress.

I'm close now to gluing in the cables. Also trying to sort out a pump , i'm thinking the MPC655 won't cut it, looking at little giants atm.

[technogiant]

I may well be coming to you for advice on water loop components if I take that upgrade path.

[Orthello77]

Yeah would love to help. Re the pump , Drew recommend the little giant 3-MD-SC little giant to me , he's tested it at -50c for 100 hrs so it should do the job nicely if i can get it here.

[technogiant]

wow...don't think I have the space in my case for that one....that little giant ain't little enough...I'd have to go small with low viscosity methanol based coolant.

[Orthello77]

lol .. its going to be outside (like rest of the A/C chiller) so noise / space is of no concern .. i just don't want any disasters like a pump cracking etc. Spent enough on the build so far to have it let down by a pump. Trick will be seeing if i can get it here , might have to look at the iwaki pumps also if i can't get a suitable model LG here. Two MCP 655s might have done the job but they are cheaply built compared to these pumps and not rated like these are for chemical exposure.

Additional Comment:

Picking up pump tommorrow , its a little giant 3MD-HC. I was really after the SC model but its not available here and importing the SC would cost nearly 80 % of what i'm paying here for the HC (thats if i don't get stung with GST on import) lol. The HC pump housing is more corrosive resistant and it can dry run so that may help with the priming a bit , no huge stress if it dry runs for a few seconds while i'm priming it. At least i have local warranty if things go wrong.

I looked at Iwaki's but man they are expensive .. i'm saving over 50% buying the lg compared to an equivalent Iwaki model.

Still looking for an ATX removable tray .. man they are hard to find now. I had one years ago but long since discarded. Any ideas ?