Andy's Freezer

[zakelwe]

I've been perfecting my very own chiller for benching 3dmark, I have no tools and no experience but I wished to move on from cold air . My previous cold air results have been in the 0-10C range

http://www.aocb77.dsl.pipex.com/tempFeb1.jpg

but I'm getting too old to sit up at 3am in the morning with the room at that temp and wish to bench in summer with the BBQ going and a beer in hand at those temps. So I am going chillers for dummy's

You can see my first attempt here

http://www.xtremesystems.org/forums/...&pagenumber=24

Very inefficent, 26 hours to get down to -29C and then warms up in 2 hours to 0C which is still better than air but can be improved. With advice from this forum I have patched up my freezer to give me a watertight container so the coolant is in direct contact with the sides :-



This goes from 18C to -5C in 9 hours so a lot better, does -20C to -26C in a couple of hours. Not fantastic but there is over 40 litres in there. Might have to trim that back with further tweaks.

I was going to use 50:50 methanol / water mixture, but it was still too flammable, have gone for a gloupy glycol / water / methanol mixture .. poor old water pump .. Might have to buy another and have two inline, but will see how the testing goes.

Note my very black sealant on the tub, no leaks yet and is still fairly flexible at -26C, might be OK after all. Will test tonight with 80w load off my Peltier.

Regards

Andy

[KennethChong]

What are the dimensions of that?

[zakelwe]

Originally posted by KennethChong
What are the dimensions of that?

It's about 3cm x 3cm x 4cm because the orange beak sticks out .

Regards

Andy

[Gary Lloyd]

I would not trust that res to hold ANY methanol. It is just too iffy and dangerous. Stay with glycol.

You can reduce the amount of liquid needed by filling the center of the res to reduce the space. Bricks come to mind, although these would be very heavy. Anything that reduces the space would reduce the liquid and result in a faster pulldown time.

[kommando]

A home made alumium res

To just fit inside the freezer on the top..

[zakelwe]

Originally posted by Gary Lloyd
I would not trust that res to hold ANY methanol. It is just too iffy and dangerous. Stay with glycol.

You can reduce the amount of liquid needed by filling the center of the res to reduce the space. Bricks come to mind, although these would be very heavy. Anything that reduces the space would reduce the liquid and result in a faster pulldown time.

That's a good idea Gary. More surface area on the sides then per cc kiquid.

I've also written off methanol as well, it is too dangerous, you need 50:50 mixtore or so to go down low and that is too flammable. I might be ok with 15% but that means freezing.

I am going to use glycol and two pumps to get the flowrate. I'm off to Hlafords tonight see if they still have the really good stuff.

Regards

Andy

[hallowen]

Here's what I've been able to do so far.

I'm using a 15% Ethanol/85% Glycol Mix(2 gal Ethanol/13 gal Glycol). I have a submersible 490 gal/hr Beckett pond pump for good flow.

Since my CPU is under a Vapo, I'm usng this system to cool my MCW-50T(172 watt pelt@20 vdc) on my 9800XT.

Still experimenting with mixtures,but like Gary has said , I don't want to create a Bomb!

Don't know if I can disassemble the walls to expose the coils but this freezer has Always been watertight and I should probably leave it intact.

Got some Pics:

[hallowen]

more:

[hallowen]

And one more:

BTW:

That's an Excellent Idea about putting something in the center of the freezer box to displace the liquid so it has more cooling surface area contact.

I'm going to give that a try

[KennethChong]

gl with it, ill be curious to see how it preforms.

[hallowen]

Went and bought a $5 trash container and used 100LBS of weights from my old weight bench.

Seems to give the fluid a LOT more cooling surface area.

We'll just wait and see how it works.

[hallowen]

KennethChong,

I would be Interested in how you got your nb/9800 to -39C!

[afireinside]

I'm pretty sure he built his own chiller like I'm going to do soon. Either that or he has a hightly tweaked window AC chiller.

[KennethChong]

Originally posted by hallowen
Went and bought a $5 trash container and used 100LBS of weights from my old weight bench.

Seems to give the fluid a LOT more cooling surface area.

We'll just wait and see how it works.

yea, I had a few sheets of old sheet metal that i used, make a pretty large stack inside of the res, and it REALLY helps to keep your temps low

[KennethChong]

Originally posted by afireinside
I'm pretty sure he built his own chiller like I'm going to do soon. Either that or he has a hightly tweaked window AC chiller.

yea i built my own, i used a pretty powerfull compressor though, im sure i could get more out of it, I have a pic of it on my home pc, ill post it later tonight. its the same one that gary used to do his first cascade if im not mistaken.

[hallowen]

Would appreciate any Pics/details on your chiller,

Thanks Guys

[zakelwe]

Originally posted by hallowen
Here's what I've been able to do so far.

I'm using a 15% Ethanol/85% Glycol Mix(2 gal Ethanol/13 gal Glycol). I have a submersible 490 gal/hr Beckett pond pump for good flow.

Since my CPU is under a Vapo, I'm usng this system to cool my MCW-50T(172 watt pelt@20 vdc) on my 9800XT.

Still experimenting with mixtures,but like Gary has said , I don't want to create a Bomb!

Don't know if I can disassemble the walls to expose the coils but this freezer has Always been watertight and I should probably leave it intact.

Got some Pics:

That's pretty nifty, good luck on the weights helping. That's a lot of gallons. makes mine look small

Added the glycol tonight, now it is a pinky purple mess in there, couldn't wait for it to get down to -30C so testing at -24C. Hmmm, the mixture is so thick that the flow is just a trickle, this means the back cold plate on the Pelt is 20+C when it should be 0-10C ideally, therefore it is not going that low.

The baseline passive Dangerden is at





The Pelt is only at



Even with better insulation I don't think I could get much colder, I really think the flow rate needs a good kick.

Ahyhow I will leave it now and see how it warms up, I am hoping for 4 hours sub zero, managed two on the Pelt and 1 on the passive last time using a plastic bucket.

Regards

Andy

[hallowen]

Looks good, Andy

Let me know how cold it gets

[zakelwe]

I'll do a better run tomorrow when it has time to get colder, however after two hours the Pelt had gone down to -17C so my first reading might have been a bit low, the baseline passive block was at -3C so that is better than before when after 2 hours it was at 5C.

Swilling up against the sides is obviously making a big difference. And it is not flammable now either ! Good. You are right I think hallowen, if you could take the sides off and have the tubes in it then even better, but it would leak then no ?

What temp does your freezer get down to ? Mine does about -30C on compressor always on.

The next round of tweaks will be the brick trick if I can find something less heavy, another pump to get the fluid moving quicker and more insulation.

Regards

Andy

[hallowen]

Paul

mine only goes down to around -21C, but if I take off the sides of the freezer, it'll probably leak!

Right now, I have a problem with coolant flow.

I may have to change to a different type of pump since the flow drops off Fast the lower(Temp) I go.

I'll try some other pumps I have later, but right now I have to clean up my mobo(Vapo Goo!) 'cause I want to be ready for my Refurbished 3.2EE from Newegg thats arriving hopefully Tommorow Morning!

Get back to you Later

[zakelwe]

Originally posted by hallowen
Paul

mine only goes down to around -21C, but if I take off the sides of the freezer, it'll probably leak!

Right now, I have a problem with coolant flow.

I may have to change to a different type of pump since the flow drops off Fast the lower(Temp) I go.

I'll try some other pumps I have later, but right now I have to clean up my mobo(Vapo Goo!) 'cause I want to be ready for my Refurbished 3.2EE from Newegg thats arriving hopefully Tommorow Morning!

Get back to you Later

You have the same sort of problem as I do, poor flow at low temps. I am going to use two pumps in series, one before and one after the blocks, this should give twice as much head ( fnaar fnaar ) which of course is a good thing in watercooling.

Regards
Andy

[Çhrist0ph]

your TEC needs a lot of pressure applied to it to work effeciently. i read somewhere that around 30-40 lbs needs to be applied...

[kayl]

slap a cold plate and some heatsink paste and should see better
temps

[zakelwe]

I have it screwed shut and have artic alumina epoxy , I think it must be the flow rate ??

Tonight results

The freezer



-30C for a £88 freezer with no mods, not bad at all.

The Pelt is still not working right



The non Pelt base coldbloack was at -13.8C so the Pelt is only give me 2-3C.

I think I need to read the PUMP thread !

Regards

Andy

[berkut]

Did you epoxy that pelt ??

never epoxy a peltier