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Old 06-02-2012, 10:01 AM   #1
technogiant
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Window AC chiller box/phase change build

I originally started this thread over in the water cooling section as my plans were to use a hailea water chiller. Thread can be found here


http://forums.extremeoverclocking.co...d.php?t=362952

But my plans have evolved and tbh correctly are now more suited to this section.

The overall plan is to place the evaporator of the AC unit into a sealed chill box to obtain sub zero air temps and either just air cool the components or thermally bridge the components coolers to the evap of the AC unit or even some combination of the two.

I'll have to experiment to see how effective either method actually turns out.

So with that said my ac unit arrived today so lets start logging my progress.

So here she is, in her pristine glory before I get my screwdriver out, all 12000btu of R407c goodness.



Uploaded with ImageShack.us

The front panel came off real easily as did the outer case which basically slid off as a complete sleeve leaving all the internals on a base tray.



Uploaded with ImageShack.us

The first problem was the electrical control board, I had to disconnect everything from it and push the wiring through a hole in an internal metal shroud.....just tagged all the cables and photographed them so I could remember where they went



Uploaded with ImageShack.us

Still soon got the electrics out and reconnected them to the side of the unit so I wouldn't forget anything.....when you're 50 that happens a lot..lol.



Uploaded with ImageShack.us

The next thing were those 2 metal shrouds either side of the evap fan and the polystyrene moldings..... these were quite difficult as everything interlocks together and you have to be gentle working around the evap so as not to damage it or the pipework.

I had to resort to bending a long flange down the one side of the metal shroud nearest to the evap so I could slide it out. I was then just able to get my hand in and remove the fan from the motor shaft.
The polystyrene molding had to be broken out bit by bit as everything was tied in.

Finally I was able to remove the larger metal shroud which also supports the fan motor. I removed this so I could cut the sides off and so make a large gap between the motor and the evap once I've cut the shaft on the motor.



Uploaded with ImageShack.us

It's actually working out quite nicely, I've got a 17cm space between the evap and the ac fan motor, that gives me plenty of room to go through the wall of my chill box and place a home made shroud and and fans behind the evap blowing into the chill box.

I've included this last picture of the electrics as I need a little help.



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In the center bottom are two sensors, a black ended one was attached to the fins of the evap. The other which is in a copper cylinder was clipped to one of the pipes on the side of the evap that go back and forth through the evap fins.

I'm guessing this is due to the unit having a cooling and heating function but I'm not sure which does what function.

Also that small circular motor is to move the louvers and I guess can be removed.

Finally I'm thinking of cutting the metal tray away under the evap back as far as the motor mount....it's going to be difficult but I can't think of any other way to get my chill box to sit nicely, don't really want it balancing on that lipped tray.....unless anyone else has a better idea.

Additional Comment:

So another day done...an some more progress...I've cut the spare end of the fan motor shaft off...whilst doing it I covered the end of the motor to stop metal fillings getting into the bearings with a piece of paper...simple but hopefully effective.



Uploaded with ImageShack.us

Then I cut off the projecting end of the base tray so I can get my chill box as close as possible and sitting squarely......was tough going even with power tools.

Also mounted it on a piece of mdf on casters (thanks Drew)...makes it much more maneuverable.



Uploaded with ImageShack.us

And from a different angle so you can see the nice space I've got between the evap and motor.



Uploaded with ImageShack.us

So all seems to be going good so far, I've tested her out after all my pulling about and everything seems okay, evap was developing a nice frost anyways...

Next stage is to drop her into my chill box.

Last edited by technogiant; 06-02-2012 at 10:01 AM. Reason: Automerged Doublepost
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Old 06-02-2012, 12:24 PM   #2
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Looks good so far.
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Old 06-02-2012, 01:34 PM   #3
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Thanks Maurice, looking forward to getting it in the chill box and doing some heat load tests. On that note I'm a little concerned about that insulating material on the pipes as they approach the evaporator. I'm going to have to remove it so I can seal around it as the pipes enter the chill box......just not sure if that is going to cause a problem....just don't know why its there really?
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Old 06-02-2012, 04:01 PM   #4
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Hello again TG!

I always love seeing these sorts of projects, thanks for sharing!

Looks like you lucked out with the pipe routing being at the top of the evaporator.. makes these type of mods so much easier.

That small section of insulation is there to prevent condensation from dripping in that area and to keep the captube from rubbing on the suction line. You can go ahead and remove it. Later on you'll need to insulate the suction line from the chillbox back to the compressor, including the accumulator. It might be easier to insulate that now before the chillbox is installed. Use some soft closed cell pipe insulation. I think you'll need about 12mm thickness. If the ID of the pipe insulation is too big then you can always add a layer or two of foam tape on the tubing to increase the thickness.

Use a good quality silicon sealer like this DAP® Silicone Plus™ Premium Silicone Rubber Window & Door Sealant. http://www.dap.com/product_details.a...93&SubcatID=25
It bonds to just about any material and is good down to around -53c. Make the notch in the chillbox approx 1/4" larger than the suction line in order to give some room for vibration. The silicon will seal the gap and act as a vibration absorber.

If you want to get a quick idea of how cold it can get.. tape a temp probe onto the middle of the fins with a couple small pieces of foam tape, wrap the evap up in bath towels, blanket or something and let it rip.
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Old 06-03-2012, 10:37 AM   #5
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I've made pretty good progress today in that I've completed the chill box and done some preliminary tests.

I already had a chill box of sorts built for the project but as my ideas on the build have changed I had to chop it about a bit, but luckily it actually adapted quite well. That's another thing I've learned with this build, don't go too far ahead of yourself as your idea's will change and evolve.

The pictures are self explanatory so here we go.



Uploaded with ImageShack.us



Uploaded with ImageShack.us



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Actually that makes a nice little shelf, I was wondering where I was going to put my hard drives....sorted!



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It's all gone together quite nicely. I tested the fans and they seem to give a good circulation through the evap (3x 120mm scythe gentle typhoon 5400rpm 150cfm each).

I've also tested the fans and air con working together briefly......WOW....I've unleashed a beast.

I haven't got my temp probe yet but used a simple bulb/alcohol thermometer.

To be honest I'm a little scared of using it.....so only briefly tested it out.
with the lid off holding the thermometer in front of the evap the temp quickly plunged to -5deg C.

So I stuck the lid on.... within 15 sec or so the temp was down to -20 dec C or there about.....tbh I was in a bit of a panic to read it properly as my fans were frosting up and I was in a rush to shut down the beast.......I'm going to have to get some control on this me thinks.

I wanted to do some load testing but there is water from condensation on my fans so I think I should wait till that dries off before I try running them again.
Don't want to blow them or my psu particularly.

And one more picture to give an idea how it will finally look.



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Last edited by technogiant; 06-03-2012 at 12:01 PM.
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Old 06-03-2012, 09:05 PM   #6
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Hey Techno been enjoying viewing and reading the progress of this mod.

I've been looking at doing something similar , slighty different in that i will use an AC unit to cool liquid (hopefully , ac unit is coming) then pipe that through to video cards and cpu and then through to a radiator at the end of the loop which i will use to chill the air down so condensation does not form as the dew point delta between the air and the water blocks won't be huge (thats the theory anyway). I'm hoping to use an air tight chamber so once moisture is delt with theres no more moisture getting in.

From the above will you put an outside shell on that chiller box or try to make it air tight so the outside humidity is not an issue ?

Its looking pretty sweet so far , keep us posted.
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Old 06-04-2012, 01:37 AM   #7
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Looking good there TG!

The only problem I see is achieving an airtight seal with the top. I was going to recommend a medium sized beverage cooler as all you would have to do is add a rubber seal to the the top edge. They usually have hinged tops with a latch to draw them shut tightly. You're going to have to level out the top edges of your box to allow a flat lid to press down and seal it airtight. After you level it out maybe epoxy a 12-19mm mdf frame around the top to beef it up. Then you can add a 12-19mm mdf/styro lid with hinges,latches and rubber seal. Btw.. can't tell from the pics.. just make sure to put a bead of silicon along all those inner seams.

Frost = Air Leak. That can easily form on cooler areas of the hardware. A little trick I did on my chillbox was to add a dual pane inspection window to the top so I could check for frost. I just used two halves from a cd case.. separate the panes by the thickness of your top. That way the window won't frost up. Throw a couple cathodes inside the case to light it up so you can see what's going in there.. looks pretty cool too.

There isn't enough volume of air inside the chillbox to allow the compressor to cycle off a thermostat with the pc at load. The temps would spike causing the compressor to short cycle. The exception would be if your pc is off or in sleep mode. Not sure about PC idle, you'll have to test it and see. If the load is small enough then the compressor can cycle like a fridge to maintain temps. Just keep in mind that the compressor will need 3-5 min before a restart. I would try and keep that above 5min though. The only time you would have to worry about it being too cold is during cold boot. Mobos can experience problems booting below a certain temp.. that used to be around -30c. Just boot by -20c.

Test out the seal before powering up the pc. Let the unit run for 12hrs or so and check for frost on any part of the mobo. Don't worry.. frost won't hurt it as long as it's not powered.

SSD and platter drives must be outside the box.
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Old 06-04-2012, 04:12 PM   #8
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Thanks to both Drew and Orthello.......you've highlighted some pretty important stuff there that has been taxing my thoughts.

Orthello, your idea about the combined chill box and water cooling loops is one I was knocking around in my previous thread on the hailea water chiller.
It may well be the ultimate answer but is quite complex in all, just have to see where this goes first and I may well end up doing something similar to that myself if things don't work out how I hope.

I made the chill box as a prototype really more for proof of concept, if I can iron out the bugs I'll make a more substantial one. when I'm ready to do longer test runs I'll simply be duct taping all the seams, that together with the simple idea I had for an expansion chamber should prevent it sucking in atmospheric air because of pressure changes even if some of the seals aren't 100%. I had the lid slightly a jar when I turned it on the first time as I had cables running under it so obviously not air tight.

I've also been thinking that if I start the air con unit a short while before the fans the evap will frost up and draw all the moisture out of the enclosure so it will be dry when I start the fans.
I think starting them both at the same time is just throwing the air around as the moisture is condensing out and that's why the fans frosted....some testing to be done there.

That's an excellent idea about putting a viewing panel in the lid.....I really do need a means to monitor whats going on.

The problem about the aircon unit cycling on and off is a little more vexing. It may have been better if I'd bought an "inverter" one as they moderate the compressor power rather than just on/off modes.
Of course you would not get this problem running a water filled reservoir as you do as you have quite a large heat capacity.

This is a more difficult one. ...the ideal solution would be being able to run the compressor continually to get the lowest possible temps without getting frost and having no need to cycle on off. You never know I may luck out there when I'm load testing, I may find it will run continuously with out frosting up, could even put a heat source in the box that kicks in below a certain temp to prevent it dropping too low and frosting everything when pc power use is low rather than have the compressor cycle on/off.

Or even better, I could sit the evap in a small reservoir of water that would come only part way up the evap rad, it would add heat capacity to the system and chill the evap during the compressor down times.

The problem behind this is frosting, if I can solve that then the compressor can run all it likes without need to cycle.

As regards hdd and ssd's your right , I was looking up mfr's spec last night, they don't like low temps.
Edited by technogiant - Today at 8:41 am

Additional Comment:

Well I've done some more testing today and its good and bad news.

The good news is that the chill box was holding a 2kw heat load at +3 deg C and a 150watt load at off scale below -20 deg C.

The bad news is condensation.

I have to admit my original concept is flawed. I thought that condensation would only form on actively cooled surfaces with a large temp delta between it and the surrounding air.
Sadly that's not the case. It's nothing to do with moisture ingress into the chill box, its just the plain fact that as air cools it can hold less moisture and will dump it on any surface regardless of whether that surface is chilled or of its temp delta with the air.

I tried turning on the air con unit before the fans in the hope it would suck the moisture out, but the chill box air temp doesn't actually drop much until you turn on the fans on, then I guess it just dumps more moisture.

To put a positive slant on this though I haven't destroyed any computer equipment during my testing and still have a very capable ac unit which I'm sure I can adapt to a cooling solution of some sorts, this is just a back to the drawing board moment.

I'd appreciate suggestions and I WILL BE BACK.

Last edited by technogiant; 06-04-2012 at 04:12 PM. Reason: Automerged Doublepost
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Old 06-04-2012, 06:51 PM   #9
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TG interesting stuff. I hope we can figure this condensation issue out without insulating everything as that is a real pain.

I almost wonder if putting the enclosure under a slight vacuum would help the cause , eg less air in the air tight enclosure - that may also be counter productive to the air cooling. Possibly another way to do it with the enclosure would be to pump dry air into the enclosure. Eg i know if i take air from my garage its a lot more damp than from inside the living room where the AC has made the air more dry. This is all assuming an air tight enclosure which is not easy to setup but i think essential in the long run. I have run with a 20c delta , about 28c in my living room with 8c liquid (outside chilled water - see my system in the top thread in waterchilled category) with no condensation for extended periods, the air was very dry due to my living room a/c.

One thing i thought was to possibly put some of those moisture absorbing pallets into the chamber , its a oncer in that if its not air tight they will absorb moisture and thats that but it could help. They might actually more readily absorb the moisture in the air pre-empting the other surfaces getting wet.

Hey you are further along than me so the above all may not work i guess i will find out soon also. Maybe Drews got a bright spark idea ? , heres one that is out of leftwest - is there any readily available non harmfull alternative to air possibly that could be pumped into the enclosure if its air tight ? Eg some gas that doesn't contain water ?

Just all ideas :-)

Additional Comment:

TG i've just been thinking , something i might consider in my build to get rid of the condensation issue is to submerse the components in mineral oil. I would use the water blocks to target heat specifically from GPU and CPU as i believe that would still be best and then after the GPU and CPU block i would run through to a radiator with a pump some how combined over the radiator to provide circulation to the components. That way i get targetted cooling with high efficiency to the cores of the cpu and water block and still get cooling to the rest of the components as a bonus.

My A/C unit will be outside the house to get rid of noise , so neccessarily i need the A/C evapourater seperate from the chill box if you like , so the above would work for me.

Sure it has negatives but it does solve the condensation problem 100 % for what i'm proposing to do.

Last edited by Orthello77; 06-04-2012 at 06:51 PM. Reason: Automerged Doublepost
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Old 06-04-2012, 11:39 PM   #10
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It just isn't sealed airtight yet. Keep in mind that there's a substantial pressure being exerted on the box due to the temp difference. Same type of force you feel when opening up a refrigerator. It doesn't take much of a leak as the air is being forced in. The water vapor in the air will condense and immediately freeze to any sub 0c surface it collides with. Desiccants won't help if there's a leak.. they would just become saturated quickly. If the unit is sealed then they can help pull residual moisture out of the air.

You only need 200cfm tops for this. The lower air velocity will make it easier for the evap fins to catch and hold/freeze the water vapor. A puller fan config would give smoother, more balanced flow through the evap fins and allow you to spot frost buildup quicker.

I really think you need to level the top edges and install a lid that seals against a gasket with some clamping pressure. Silicon all cracks.. maybe even spray/brush the outside with rubberized undercoating or something. Just seal it and you'll be fine!

That's great news on the capacity. It'S A BEAST!


Hello Orthello77!

I see you're also interested in building a chillbox. As you can see, the main issue is achieving an airtight seal. The suction line, cables and wires are pretty easy to seal using silicon. Sealing the top is the biggest hurdle. Once sealed, there is only the initial moisture to deal with. The evap will pull that out of the air in seconds upon startup.

Keeping the chillbox pressurized with a dry gas is another option, as you mentioned dry air, maybe even CO2 or Argon if you have access to it. I know one fella used Nitrogen.. but due to the poor thermal properties had to wc all components.

Hope to see your build as well!

Welcome to EOCF!

-Drew
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Old 06-05-2012, 04:12 AM   #11
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Thanks for the positivity guy's.....sorry I was having a bit of a down day yesterday......I haven't given up on this yet...the cooling potential is awesome.

Orthello. I've also considered mineral oil submersion, but it brings it's own problems, you have to seal some of the motherboard components, capacitor, against oil penetration, so its equally as much of a pain as sealing for condensation.
Also running oil through water blocks would be less efficient as oil has a specific heat capacity of 1.7 as opposed to 4.2 for water, the blocks would need a larger surface area. On top of that oil becomes viscous at below 10 deg c and doesn't pump so well.

I've also considered putting desiccant sachets in there, that may help by giving it a dryer starting point, but tbh I thought that the low evap temp would pretty much suck the humidity out?

The idea of pumping in a dry gas source would be good.....but tbh other than having a compressed gas cylinder or perhaps an air compressor pumping through a desiccant filter bed......all a little more extreme than I wanted to go.

Drew, I think I've pretty much sealed it all up, okay it's looking very ghetto now covered in duct tape so no pictures.

Also I used my expansion chamber idea. (remember plastic bag on breather pipe...lol)...so I'm equalizing the inside and outside pressure to further reduce leakage.

Obviously you can never completely seal but I think it's good enough to test this concept for now, if it works I will spend out more on a robust build.

I think we have come to the solution simultaneously here, it's the fans.

When I ran the evap initially for a period before starting the fans, giving the evap chance to dry the air, that did reduce the frost/condensation.

But I also noticed (using your viewing panel idea) that while doing this the temp in the chill box didn't alter much till I turned the fans on, then it plummets from +20 to minus figures in a very short time.

I think this rapid drop is causing the moisture to dump anywhere.

I need to give it time to condense on the evap. I have no control on those fans yet. Also getting some control on the evap temp may also help to give a slower start.

I'll also reverse the flow on my fans atm they are pushing through the evap,
could even pack some desiccant in the chamber behind the evap.

I'm a little concerned about running the evap on its own first without the fans or any load, I don't want to damage the compressor, any ideas how long I could safely do this, it appears to be a rotary compressor with built in accumulator?

Additional Comment:

Just done some more testing, this time I again let the ac unit run for a bit on its own, then started pulsing the fans on/off just for brief periods so the temp gradually dropped.

Got down to -20 with a 150 watt heat load with no signs of condensation.

One thing I have noticed that seems to be giving false indications of condensation.

Before I open the box after a run I've been leaving the heat source on to speed up the return of the chill box to room temp.

Whats happening is that there are "dead spots" which don't heat up as fast and so remain colder than the chill box air, these dead spots then form condensation.

I think its probably wise to let the system temp return to normal passively , perhaps even leaving the fans run to even out the internal temps.

So its time to put some control on those fans. Don't want to spend out much on this sort of thing (already spend £70 on a rad I don't now need)....any suggestions.

I'm happy this is going to work now so I'm going to rebuild the chill box properly.

I want to give it a hard shell and obviously an insulating layer, not really sure of the best materials to use, I guess things like MDF would be porous and not suitable?

I'm thinking perhaps a plastic box for the interior air tight layer surrounded by insulation and then a hard shell, perhaps MDF would then suffice for the outer layer? Also how would plastic stand up to sub zero temps?

Just stumbled across another possible problem.. my intention was to put my psu in the chill box, but looking at the mfr spec operating temp range is only down to 0 deg C .....storage temp down -20 deg C.

If I have to run the all the cables through the box wall that's going to be a problem to seal, even if you adequately seal on the outside of the cable vapor will track between the cables bundled together.

Last edited by technogiant; 06-05-2012 at 05:09 AM. Reason: Automerged Doublepost
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Old 06-05-2012, 05:40 AM   #12
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TG, glad to hear its working a lot better now with the added duct tape , it proves that getting more air tight is the way to go.

Fan control should not be too expensive, any 12v pc fan header would do the job and give you some quite fine control. Long term i would recommend you get a fan header that accepts a PWM signal from your motherboard, most of these are controllable via SpeedFAN which is free , its a great utility i use to control FAN RPM at certain temperatures. That ways its automatic and controllable via windows. I use this to speed up fan RPM of my external water cooler when the GPUs temperature climbs but it can be set to work off CPU temperature also. I have a sunbeam 30w x 6channel controller with PWM control, its a bit overkill for your needs (i run 12 scythe ultras on the single controller) but something like that. If you have 3 fans to control any controller with PWM input could do the trick. The sunbeam controller is very cool in that you can make it manually controlled as well so you can overide the PWM settings at the press of a button.

Re the enclosure what i'm thinking is plastic / perspex outer shell , with Gasket for upper lid. Lay the inside with Polystyrene siliconed in place to provide the insulation. To simply make it on a budget i would suggest silicon and perspex (maybe 5mm - 8mm would suffice), a hacksaw (if you are fit) or jigsaw would be easier to cut sides and then just silicon in place. It works for fish tanks so it should work here with way less pressure (i would think). The lid will be the hard part , thats where you need to make some form of gasket and screw in i would think.

I think a thin slit long and thin will allow nearly all the necessary cables through , that way you can put the cables side by side after they are through and silicon around them not all in one bunch. It may prove difficult but i'm sure it won't be a show stopper.

Just waiting for the A/C to show up now , will take heaps of photos for Drew to analyse ! 730g of r410a in the charge. BTU similar to your unit. hopefully its suitable for the mod. Fingers crossed.
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Old 06-05-2012, 08:54 AM   #13
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Thanks for that Orthello....glad to hear you also making a start on your build, looking forward to seeing it.

I'm a little confused with these fan headers, I'm new to this stuff.
The wiring loom that came on my fans consists of two molex connectors (one male and one female) and a 3 pin plug.....but the 3 pin plug only has one yellow wire attached to it. the molex connector has two additional wires piggy backed on to it a black one (attached to black on the molex) and a red one (attached to yellow on the molex) and these go to the fan.

I'm guessing these two extra wires would normally be attached to the 3 pin adapter and probably due to the current draw on these scythes they use molex for power and the yellow cable via the 3 pin plug for PWM control?

Trouble is that most of the fan controllers use 3 pin connectors. I've just looked up molex to 3 pin adapters and they use two wires red and black to a 3 pin plug, so I guess I'd have to use one of those to connect to the fan controller and the 3 pin with the yellow cable to the mobo if I was also able to use pwm control through windows?

Last edited by technogiant; 06-05-2012 at 12:32 PM.
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Old 06-05-2012, 01:49 PM   #14
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TG, those scythes with molex connecters are a little odd , all my ultra kaze scythes have the 3 pin, i think scythe may have made them with molex for oem setups where the motheroboards have fewer fan headers built in. Anyway just as long as you get the red/black to the red/black on a 3 pin connecter, either solder or cable adapter the 3pin header on fan controller or motherboard will easily power it. The yellow is to sense RPM so yellow to yellow here. Most Fan headers will do 10watt per channel, so you can run 2 scythes of one channel if they use less than 0.5 watt each.

I should have mentioned theres 2 ways to do this. One is use your motherboard if you have 2 or more fan headers to control the fans directly from the motherboard. The negatives with this is no manual control. You can still control all fans via Speedfan in windows as each header can be controlled individually. It could save you the fan header expense if you can forgo the manual control. Just thinking about this , my experience is that you can run atleast two fans of one header they seem to be quite beefy. I ran 2 scyth ultras off one motherboard header and they use 0.6amps each.

The other way is the fan header this gives us manual control , and possibly auto control if the fan header supports it.

The PWM cable plugs into the 4 pin Fan header output near the cpu. The 4th pin is the PWM signal. I think it is the CPU fan connector for me as that fan would likely support PWM if i used air cooling. Physically only two wires are used and it connects directly to my fan controller. PWM either works by modulating the voltage or more commonly by pulsing the 12v signal extremely fast to achieve lower rpm rates. What i use is that one single PWM cable from the mobo to the fan header. Then all fans off that fan header get the same RPM across them. I am running 12 fans so that made it easy.

Just one last thing, the yellow wire is not critical for the PWM to work , eg its effectively an RPM sensor wire only, eg just one fan would need the Yellow wire connected through to mobo / fan header to give you a reading to work off. PWM modulates the signal over the red wires only, black is ground. Out of the 12 fans i have , i just connected 1 yellow wire to get the signal from one , even then due to PWM i guess, it gives a wierd RPM which is unusable. It still works however as you set %s in speedFan not target RPMs.

Hope that helps.
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Old 06-05-2012, 03:44 PM   #15
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Thanks very much for that Orthello, yes that explained it perfectly.

I'll have to go for quite a beefy fan controller, each of my fans draws 1.14A or 13.6watts and a whopping 2.69A on start up..

I've been giving some thought about how to pass the psu cables into the chillbox and still maintain an air tight seal. The difficulty will be the main mobo plug with all it's cables gathered together.

I was thinking of getting a small section of plastic pipe just a couple of inches or so, cutting down one side length wise so you can open it out and wrap around the cable bundle.
Cable tie one end tight and pour a light glue...perhaps pva into the open end of the pipe. Massage it to work the glue in between all the cables and allow to set. then remove the pipe and you should have all your cables set in a solid block of glue, hopefully without any channels between the cables that you can pass through the wall and seal to.

Last edited by technogiant; 06-05-2012 at 04:01 PM.
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Old 06-05-2012, 05:12 PM   #16
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Theres a few 4 x 30w per channel and 4 x 40w controllers out there, so 1 fan per channel should be fine even on startup with a controller like that (each channel good for 2.5 amps on the 30watt controllers , startup should hopefully be ok - only slightly overdrawn on startup ). That is really heavy wattage for a 12v pc fan , i'm wondering if they are pulling more current at the low temps. I'm sure the scythes ultra kazes are rated 0.6 amps at 12v and they look bigger than those fans , still i havn't run them in a freezing environment.

I like that pipe idea , i think possibly leave a short section of pipe there as it would make the perimeter join to the chamber tidy. PVA might do the trick , silicon might be too viscous for it to work.

I'm going to do a sketch up this weekend of dimensions / hole positions for the chiller chamber , the A/C could take up to two weeks to arrive so i have time to get this started at least. One way to test it i thought was to do a leak test. Eg the cables are insulated so once the cables are fitted to the chamber a small amount of water and turn the chamber upright to see if it leaks through the cable entry point. That would prove for sure it was air tight.
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Old 06-05-2012, 11:44 PM   #17
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This is the cheapest I could find with sufficient power per channel, more channels than I need but leaves room for expansion if needed.

http://www.overclockers.co.uk/showpr...=57&subcat=189

About sealing the mobo cable, I'm not sure you could leave the pipe on as you would have had to have split it length ways to get it over the cable, as it won't fit over the mobo plug, I think the split would make a channel for air to get through.

I'm going to start buying some things like short male to female usb cables so I can pass them through the box wall and seal them. Basically all the cables I'll ever need will have to be put through as once its done its done, it will be difficult to add to later.
It would be nice to somehow leak test it once complete.

A big problem though is the logistics of how you are going to put it together.
Once you have the ac unit apart you can't easily move it around. You can't just dangle that evap on the end of its pipework and have to move them both together. As they weigh around 45 kilo that's no easy task.

I've taken the approach of building the box around the evap rather than building the box and then trying to lower the unit into it. But that in itself requires some extra planing as to how you are going to do things.
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Old 06-06-2012, 02:18 AM   #18
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That Fan controller is good quality and loads of power per channel. It has no PWM input but thats not a biggy if you want to mainly have manual control of the fans anyway.

Re the cabling i just had an idea, i have some starbrite liquid electrical tape i think i will zip tie them hard then silicon around them, for the ends ( in between ) i will drip in the starbrite stuff as its flows freely thens sets in minutes. Or possibly its best just to put it right throughout without silicon. I have used this on my outside watercooler for cable insulation works well.

Good idea on the usb cable extenders, its not like later on you can say **** i need an extra usb after its all sealed !

Yeah i think that is very wise, build the box around the evap rather than try to conform the evap , the less you have to maneuver the piping the better. The unit i have coming is a portable AC 12500 BTU , but i don't know what it looks like underneath yet so fingers crossed. I tried to find your unit on the shelves here as a second option if my a/c doesnt work out, in fact the window-banger type a/c unit here is almost extinct as far as new goes, even second hand i saw no window-bangers just wall mounted a/c's and portables, and i didn't fancy making a heat exchanger out of the wall mounted evapourater (huge).

I'm just getting fustrated at the momment as its not arriving already lol.
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Old 06-06-2012, 01:26 PM   #19
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That starbrite sounds just the job, and they sell it in the UK

http://www.amazon.co.uk/dp/B0000AXNO...SIN=B0000AXNOD

Yeah I think it's important to find a good method of doing this, because again you've really got to put all your psu cables that you may need through in the first place, too much of a mess later.

I bought my unit off ebay, he had 5 for sale, but I think postage to the US would be astronomical...lol.

Hope you get lucky as I did with the pipe lay out...just no way of telling have to take your chances...but I'm sure you'll be able to work around any problems.

I'm going to be in work the rest of today and tomorrow so can't do anymore till Friday :-/

Additional Comment:

I'm looking to buy acrylic sheet for the outer shell.....do you think 6mm will be thick enough?

Last edited by technogiant; 06-06-2012 at 01:26 PM. Reason: Automerged Doublepost
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Old 06-06-2012, 01:56 PM   #20
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6 mm should do the job nicely.

I got impulsive today and managed to pick up an A/C unit i think identical to the one i have coming , same specs 12500BTU 3500watt, same look just different brand , second hand not new for about 40% of the price so i have a spare in a sense now or i'll just sell one of them. I just want to get started this weekend , wife is away the whole weekend !

So hopefully will get it stripped down and get some photos up tonight. The layout isn't going to be as tidy as yours but it should still work. The evapourater looks situated above the compresser / condenser. Its really hard to find any window-banger type models here , havn't seen a single one online. Anyway i'll put some pics up once i have it on the workbench :-)
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