Basic Questions on chilling

[Onycho]

Okay, just trying to get some information all in one place. I want to build a chiller along the size lines of chilly1's Liquid Frostbyte. And as you may gather from the questions as I ask them, I'm pretty new to all of this but I want to learn because this is becoming an obsessive hobby and unless you do this stuff yourself, it's a really damn expensive hobby :rolleyes:

Question 1: What are the statistics of the compressors that I would need to achieve the following temperature ranges? ie, What do I need to look for on ebay or other resale areas?

0 to -20C

Use a low temp compressor with R134a for the nessassary capacity high pack pressure for say a 200W load use an aea4440 tecumseh(Creds to chilly1) -20C to -40C

Use a low backpressure medium temp compressr for 134a with R507 and an oil change to low temp oil 300w load use aea9415 Techumseh (Creds to chilly1) -40C to -60C (or as low as possible without a cascade)

Use a low backpressue Danfoss sc12 m series or 15C series or a 1/2 hp medium temp tecumseh/ (Creds to chilly1) Question 2: Heat exchangers, which ones work best or comments on where the different types excel.

Tube in shell

Tube in tube

Plate

Question 3: For the above heat exchangers, what is the approximate size of a good resevoir? I know more has a larger heat capacity and buffers against temperature changes but at the cost of longer pull down times and an increase of overall temps. So I assume, especially based on some of Gary's posts that there is a real balance as far as resevoir size goes. What are the general rules for this?

Question 4: How much does the block matter? I know that in normal water cooling there is a big difference between say a Storm 4 and a Maze 4 but how much of a difference does it really make in subzero temps?

As noted same as above zero - a better block gets you lower temps. You should really get the best block possible, but one that's easy to insulate is probably a better choice in reality. (Creds to Tyrou and Butcher) Question 5: What is the "best" tube size to use for the chilled liquid? What is the difference between using 3/8" and 1/2"?

1/2" - it's 80% larger which makes for much better flow, especially at low temps due to viscosity increases. Also for parallel, 1/2" is virtually a must to reduce pressure losses from tubing. (Creds to Tyrou and Butcher) Question 6: What are some good books that I could get to learn the basics of working with AC? Are there some "Idiot's Guide to AC" books or similiar?

Check Gary Lloyd's book (http://www.merchantamerica.com/tmethod/) out(Creds to chilly1) Question 7: I've seen the posts about pumps on the liquid cooling forum but my question is which survive the cold temps best? I think the Iwaki is the general consensus but I would appreciate some feedback on this.

LOL...just like every other thread on this forum...depends. It's choice and really not one that is over and above the rest. Take what information you get and make the best choice. Like trying to ask people if it's better to get pentium or AMD...LOL Question 8: When cooling 2 GPUs, North, & CPU, is it best to do all in series or do 2 parallel loops? If in series, what is the best order to have the flow go or does it even matter at these temperatures?

General consensus seems to be series due to pressure drop when running in parallel.[/QUOTE] Question 9: Considering the temps involved and the fact that there will probably be dissimiliar metals in the loop, what are the best fluids to use? I don't want slushing, freezing, or any electrolytic effects.

[QUOTE]Florinert but it is expensive.
(I looked into Fluorinert and I think that FC-77 (http://products3.3m.com/catalog/us/en001/oil_gas/specialty_materials/node_L98WR0Q8WQbe/root_GST1T4S9TCgv/vroot_G1F6DNZDBVge/gvel_M2C4BHRN70gl/theme_us_oilgas_3_0/command_AbcPageHandler/output_html) seems to be the best for our uses, having a range from -110C to 97C (Onycho)) Question 10: WTF does prommie mean?

An endearing name for Prometeia :D To everyone that answers, thanks a whole lot. :toast:

[enzoR]

prommie? lol those are promethia mach1/2/ect units. its that company that sells cpu cooling devices, just like vapochill. i'm sure youve heard of em.

[Tyrou]

Q1 : depends of the heat your computer produces, but for 0/-20, a 1/4HP should be ok, for -40, at least 1/3, but 1/2 would be great to keep this temp under load, after -40, it will be a pain to find a liquid with good thermal properties, not so high viscosity and that doesn't freeze :(

Q2 : I would go for a tube in tube, as it's easy to build, and sufficiently efficient

Q3 : if you use a tube in tube HX, you don't need any tank, maybe an airtrap on the suction line of the pump to fill your system :)

Q4 : the same différences exists between blocks, but as you're ~50°C lower, you don't care about it :D

Q5 : 1/2, viscosity grows when temperature goes down, so the flow decreases, and 1/2" hoses help to keep it correct

[Onycho]

Thanks for the answers Tyrou. But I'm looking to buy the heat exchanger and I'd like to know the capabilities of the tube in shell and plate exchangers as well. I want to know which is more effective.

As to the resevoir, I was looking to have a bit of a buffer in case of a failure in the system, without sacrificing too much cooling as well as making for a gradual pull down. Also, I wanted to set it so that when the system is turned off, the pump will keep things circulating for about 15 minutes to allow temps to rise slowly. The idea was to decrease thermal stresses on components.

[chilly1]

Answers in the locations of teh questions

Okay, just trying to get some information all in one place. I want to build a chiller along the size lines of chilly1's Liquid Frostbyte. And as you may gather from the questions as I ask them, I'm pretty new to all of this but I want to learn because this is becoming an obsessive hobby and unless you do this stuff yourself, it's a really damn expensive hobby :rolleyes:

Question 1: What are the statistics of the compressors that I would need to achieve the following temperature ranges? ie, What do I need to look for on ebay or other resale areas?

0 to -20CUse a low temp compressor with R134a for the nessassary capacity high pack pressure for say a 200W load use an aea4440 tecumseh
-20C to -40C Use a low backpressure medium temp compressr for 134a with R507 and an oil change to low temp oil 300w load use aea9415 Techumseh
-40C to -60C (or as low as possible without a cascade) Use a low backpressue Danfoss sc12 m series or 15C series or a 1/2 hp medium temp tecumseh/

Question 2: Heat exchangers, which ones work best or comments on where the different types excel.
use a coil of copper in a tank or a shell and tube but with the shell and tube use care not to freeze it up
Tube in shell

Tube in tube

Plate

Question 3: For the above heat exchangers, what is the approximate size of a good resevoir? I know more has a larger heat capacity and buffers against temperature changes but at the cost of longer pull down times and an increase of overall temps. So I assume, especially based on some of Gary's posts that there is a real balance as far as resevoir size goes. What are the general rules for this?I would use as large a rez as I could fit in my space and insulate well this will reduce run time of the compressor and give you some off time for the icing to lesson
Question 4: How much does the block matter? I know that in normal water cooling there is a big difference between say a Storm 4 and a Maze 4 but how much of a difference does it really make in subzero temps?

Question 5: What is the "best" tube size to use for the chilled liquid? What is the difference between using 3/8" and 1/2"? 3/8 the differance about 1/8 inch :D
Question 6: What are some good books that I could get to learn the basics of working with AC? Are there some "Idiot's Guide to AC" books or similiar? Check gary lloyds book out

Question 7: I've seen the posts about pumps on the liquid cooling forum but my question is which survive the cold temps best? I think the Iwaki is the general consensus but I would appreciate some feedback on this.
Find a pump with an isolated motor and an insulated housing
Question 8: When cooling 2 GPUs, North, & CPU, is it best to do all in series or do 2 parallel loops? If in series, what is the best order to have the flow go or does it even matter at these temperatures?
Parallel is always best you will need a pume with enough flow to handle it.

Question 9: Considering the temps involved and the fact that there will probably be dissimiliar metals in the loop, what are the best fluids to use? I don't want slushing, freezing, or any electrolytic effects.
Florinert but it is expensive.
Question 10: WTF does prommie mean?
An endearing name for Prometeia :D
To everyone that answers, thanks a whole lot. :toast:

edit 01/21/05@1652PST: Added questions 9 and 10

[gkiing]

well answered. Flourinert is far overpriced.

[Onycho]

Thanks for all the great info chilly1. But I have some follow up questions....

Question 2: Heat exchangers, which ones work best or comments on where the different types excel.

Quote:
use a coil of copper in a tank or a shell and tube but with the shell and tube use care not to freeze it up

Which do you recommend as being the most efficient? I would prefer to buy an exchanger, off the shelf, but I want what is most effective.


Question 7: I've seen the posts about pumps on the liquid cooling forum but my question is which survive the cold temps best? I think the Iwaki is the general consensus but I would appreciate some feedback on this.

Quote:
Find a pump with an isolated motor and an insulated housing

But do you have any recommendations as to brand, make and model?


Question 9: Considering the temps involved and the fact that there will probably be dissimiliar metals in the loop, what are the best fluids to use? I don't want slushing, freezing, or any electrolytic effects.

Quote:
Florinert but it is expensive.

So would that be this (http://products3.3m.com/catalog/us/en001/oil_gas/specialty_materials/node_L98WR0Q8WQbe/root_GST1T4S9TCgv/vroot_G1F6DNZDBVge/gvel_M2C4BHRN70gl/theme_us_oilgas_3_0/command_AbcPageHandler/output_html)?

Where to buy, where to buy?

Thanks again for all the great info! :toast:

[chilly1]

Thanks for all the great info chilly1. But I have some follow up questions....



Which do you recommend as being the most efficient? I would prefer to buy an exchanger, off the shelf, but I want what is most effective.

Well I would check use a beckett 800 GPH from home depot and see what happens.. Ice is what kills these.

But do you have any recommendations as to brand, make and model?




So would that be this (http://products3.3m.com/catalog/us/en001/oil_gas/specialty_materials/node_L98WR0Q8WQbe/root_GST1T4S9TCgv/vroot_G1F6DNZDBVge/gvel_M2C4BHRN70gl/theme_us_oilgas_3_0/command_AbcPageHandler/output_html)?

Where to buy, where to buy?

Thanks again for all the great info! :toast:

Check with them by email for a local rep. I spoke with a sulpplier in washington state and they wanted 65 per gallon and a 5 callon minium..

[saratoga]

Parallel is always best you will need a pume with enough flow to handle it.


To elaborate, parallel is "best" if you have a LOT of flow. Ideally for parallel you have one pump per loop.

For more practical systems (99% of those you see on these boards) serial is better. Pressure has a tremendous impact on performance, and everytime you add a split, you halve pressure (or do some other split between the branches, 40/60 whatever). So while serial will have slight heating between componets, it will generally still cool better because flow in parallel systems is generally so poor.

[Onycho]

Quote:
Well I would check use a beckett 800 GPH from home depot and see what happens.. Ice is what kills these.

Is this (http://www.wholesalepumps.com/Product.cfm?DID=12&PID=659) the pump you mean? I checked the home depot website and they didn't have the 800GPH pump, only the 1100GPH pump. What is the heat generation on the Beckett like? Also it shows as a submersible pump, so you recommend that the pump be placed in the resevoir? Also, how noisy is it? (don't worry about ice, I'll definately be getting Fluorinert). Final question on pump...also showing how little I understand some of this...using 3/8" tubing would this pump be able to generate enough pressure to keep a parallel system viable? There would be two loops...one cooling 2 x GPU and ram heatsinks (SLI) and one cooling the CPU and SLI controller (I WILL find a way to make it fit!). Also I would probably be keeping this about prommie sized and probably keeping the unit on the floor next to the computer itself so as to keep the actual loop length as short as possible.

And speaking of Fluorinert...I'm in washington state...5 gallons at $65 isn't bad if there's a resale value (hint hint, nudge nudge, wink wink). :D

As to the HX, since ice won't be a problem what specs would you recommend on the tube in shell?

[chilly1]

they said 65 for each gallon and only in 5 gallon pails

[Onycho]

LOL, I knew that. Bad typo on my end....still as I said, 5 gallons at $65 a gallon isn't bad...divvy up into 1 Liter allotments and resale... :D

So who was this distributor chilly1? ;)

[chilly1]

Dont remember I tried to look it up..I googled it and then called dupont chemical I left my phone and they called me back.

PM extremecorvette he may know of a contact..

[gkiing]

Just use denatured alcohol or windshield washer fluid. They work ok as long as your careful.. but wwf is flammable, toxic through skin, and causes blindness if swallowed :p:

[Onycho]

chilly1,

Earlier you posted this....

Question 3: For the above heat exchangers, what is the approximate size of a good resevoir? I know more has a larger heat capacity and buffers against temperature changes but at the cost of longer pull down times and an increase of overall temps. So I assume, especially based on some of Gary's posts that there is a real balance as far as resevoir size goes. What are the general rules for this?
Quote:
I would use as large a rez as I could fit in my space and insulate well this will reduce run time of the compressor and give you some off time for the icing to lesson

Is there some limit on the rez before the size actually starts hurting temps? What I'm looking for is kinda an ideal range. I really, really want to do this right the first time cause I don't have the money nor time to experiment (I'm a full time University student with a wife and son...that I'm getting this far is a miracle... :rolleyes: )

[Butcher_]

Question 4: How much does the block matter? I know that in normal water cooling there is a big difference between say a Storm 4 and a Maze 4 but how much of a difference does it really make in subzero temps?
As noted same as above zero - a better block gets you lower temps. You should really get the best block possible, but one that's easy to insulate is probably a better choice in reality.

Question 5: What is the "best" tube size to use for the chilled liquid? What is the difference between using 3/8" and 1/2"?
1/2" - it's 80% larger which makes for much better flow, especially at low temps due to viscosity increases. Also for parallel, 1/2" is virtually a must to reduce pressure losses from tubing.
If I were you, I'd go serial - you'll get better performance.

[Tyrou]

for the reservoir, I use a 5 liters (~1.2gallon) plastic tank, insulated with 2" of polyurethan expansive foam, it only losts 4°C in 8 hours :)

[gkiing]

Plastic/PVC cracks around -35 (I had a ABS pipe res crack after running a chiller for 6 hours with -40c liquid) but if you stay around -25-30 you should be ok.

[Onycho]

What I was actually thinking about for a resevoir was a design like this....

Outer shell welded aluminum,
About 1/2" to 1" layer of neoprene,
Inner tank made of a carbon fiber or some other low thermal conductivity compound.

Lid would have a silicon gasket and pressure bolted into place (bracket on lid, nuts welded to outer tank, tighten bolts from bracket into nuts to torque down the lid and seal the gasket.

I was hoping to make it so the inner tank had a volume of about 2 liters max. But my question was because I didn't know if 2 liters was too little or too much. I want to make this thing prommie sized with ALL components inside the unit...I'm a stickler for neatness and this must be as spotless as the rest of my house :banana: (okay okay, I"M INSANE :wierd: ) :banana:

[Tyrou]

making you tank is possible, but welding the aluminium is not an easy job :(

1" layer of neoprene won't be enough, put at least 2" of neoprene or PU foam, if you want a all-in-a-box, you'll have to insulate very well :)

[Onycho]

Ack...well that IS true...since the outer tank shell of the rez will be "dry" I can probably get away with a rivet job or similiar.

[Tyrou]

yes, rivets would do it fine, you also can glue it :)

[gkiing]

Or epoxy or tig weld for aluminum

[Onycho]

So Tyrou, gkiing, do either of you have any experience with the pump that chilly1 recomended? What do you recomend? There's a good discussion of pumps in just the liquid cooling forum, but really not much as far as chilled goes...

[Tyrou]

I used a Ehein 1250, made for aquariums, it worked during 6 months, but I broke the outer fitting, so I bought a MCP650, whick is ok :)

[gkiing]

I'd reccomend any of the iwaki pumps (namely the wmd od md-20RZT) or the danner/swiftech laing pump. Look for one with a METAL casing. If the impeller is plastic it will be ok as long as you dont insulate the impeller, but a metal casing is a must. Also the mag drive pumps like the iwaki and the new swiftech can push thicker liquids faster due to their higher head rating.

[LANjack]

Sticky sticky sticky sticky... could squash alot of threads.

[Onycho]

gkiing,

What is the difference between the RZT and the RLT? I saw something about it under a different thread and they seemed to recommend the RLT. Just want to make sure before I shell out for a pump.

Also, are the Iwaki's with a metal casing?

[gkiing]

The iwakis have a metal casing and a white plastic pump impeller. As long as you leave the impeller uninsulated it wont crack. The RZT has a lower free flow than the RLT but a much higher head rating, meaning it can lift water higher than the rlt and push it through a more restrictive loop (ideal for chilling).

[Onycho]

As long as you leave the impeller uninsulated it wont crack.

From the picture, this is where the hoses attach, so with the Iwaki, we don't insulate them at all? Also, from my searches, the RZT is next to impossible to find :rolleyes:

[gkiing]

If the pump you are using has a plastic impeller then you dont insulate it because if you do it will get too cold and crack. Eheim's dont have the same kind of exposed, almost separate impeller as the iwakis and the swiftech mcp600. If you cant find the RZT an RLT would be ok.

http://aquarium-supply.biz/ordering/pump_Iwaki.html

[Onycho]

Well, other than my questions about HXs and resevoir size...I think I've got a good base of info.

Now for one final extreme question....on an AMD FX-55 if I've already got a water-chiller running at -40C, would I still expect a gain on processor temp if I use a block with a 226W peltier on it? I know that's a lot of voltage to supply there and also, would the added heat from the pelt cause my compressor to not have much downtime and burn out sooner?

[gkiing]

Peltiers don't work well at such low temps, you would see a performance decrease if your chiller could actually handle the 226w + cpu (~500W, 226W tec puts our around 320W of heat).

[Onycho]

I thought it might be something like that but I had to ask. After all, if it worked, who in their extreme minds among us would settle for -40C when adding a pelt could get down even lower? :rolleyes:

[KaptCrunch]

well answered. Flourinert is far overpriced.
also very evaporative...hard cash floats in thin air

[KaptCrunch]

Dont remember I tried to look it up..I googled it and then called dupont chemical I left my phone and they called me back.

PM extremecorvette he may know of a contact..

its 3M (http://products3.3m.com/catalog/us/en001/oil_gas/specialty_materials/node_L98WR0Q8WQbe/root_GST1T4S9TCgv/vroot_G1F6DNZDBVge/gvel_M2C4BHRN70gl/theme_us_oilgas_3_0/command_AbcPageHandler/output_html)

3M Specialty Materials
3M Center
Building 223-6S-04
St. Paul, MN 55144-1000 USA
1-800-541-6752