[r0ckstarbob]

i've been tabulating data on polar coolants used in computer water cooling setups for the past 3 weeks and these are my results.

My focus for this research was to find a coolant that would work at -30F for my project aka The Core Project. for those of you considering going a sub-Z route, or just want to put your coolant below freezing (32F), this is something you'll probably be interested in.

as for using antifreeze in your system, well, the numbers speak for themselves.

big props go out to Karsta (here on the forums) and myv65 (Dave Smith on the AMDmB forums- the author of that cooling article that Hoot has stickied at the top). both of whom i've been corresponding with and have been absolutely fantastic in providing me with answers and overall knowlege when i just plain ol got stuck somewhere, trying to understand all this. these are some REALLY knowlegeable and helpful guys, and not only in regards to coolants. they've been absolutely great. i can't express enough gratitude. big props also go out to Tenax too (also on the AMDmB forums). All three of them have been of invaluable aid. Thanks guys.

i can explain anything that you might have questions on here. and if i can't, i know a couple of guys that can.




:::::::::::::::::::::::::::::: EDIT ::::::::::::::::::::::::::::::::::




it's been a long time since i initially posted this. much has changed and i've lost some of the original data due to HDD corruption and so forth. consequently, the original chart doesn't exist any longer. what DOES still exist are the graphs i created from the data in that chart, and those you can find by scrolling down the page here. sorry for the hassle and gunk, and i'm sorry the original chart doesn't exist any longer. if you want a quick and easy answer to what is the best stuff to use for a coolant, it's this...

#1 me love you long time GI....
Methanol/Distilled Water (33:66 ratio) aka windshield wiper fluid

although it's actual thermal properties aren't quite as good as straight up water, it's viscosity rocks the casbah and so what you're you loose in quality you make up for in quantity at about a 15% increase in performance over water... even at (or above) ambient room temp. sound great? well, truth is in all honesty you'll probably be hard pressed to see 15% performance increase in a real world scenario, but it should be there. this ratio will also give you an operational range of approximately 90C to -23C... or well below freezing. should use this stuff in a closed system though. or at least no bongs. this ratio of methanol to water isn't particularly lethal, but don't drink the stuff for gods sake. the other name for Methanol is wood alcohol. if you're operating above freezing temps at around ambient, go with 100% distilled water on general principle. it's just going to be better.


#2 100% Distilled water

best stuff around, damn hard to beat. no kidding. usually it's even better than the above stuff.


#3 Ethanol/Water (aka vodka) ratio varies

if you're going below zero and have moral issues with windshield wiper fluid and you just HAVE to get below zero, use Ethanol and water. Ethanol is Grain alcohol, and what they make booze out of. you want to use as little of this stuff in your water as possible so go sparingly. the more of this stuff you use, the less efficient your coolant is going to be because it's Ethanols thermal properties aren't as good as waters, and it's also thicker than water so the more of this stuff you use, the thicker your coolants going to get. don't tell your roomie you're cooling your stuff with Vodka or risk comming home to your boy on the floor with a hose in his pie hole being shotgunned by your Antec.

*** shudder ***


#4 Isopropyl/Water (aka 2-propanol aka rubbing alcohol)

ghetto fabulous baby, same cautions apply as above, this stuffs even worse than ethanol but it will work. the good points of it are your roomie won't touch it.


#5 Antifreeze/Water (50:50 ratio)

last and least good for your system... if you're hard up, don't have a leg to cut off for something better, on a desert island and only have this crap, well go for it. a 50:50 ratio will quarantee you down to -10 but the results are so disgusting compared to what you could get if you used any of the above items. i've included it here just because so many people consider this a viable option and actually do it. whats sad is they could have such better performance if they used the alcohols instead. ah well. C'est La Vie.



:::::::::::::::::::::::::::: end of edit ::::::::::::::::::::::::::



please scroll down for the graphs and charts.

i hope this is helpful. enjoy your read.

RSB

[Coolio]

WHOA now that's comprehensive!
And interesting
and informative

[train22]

very imporessive, keep us informed with real pics!

[r0ckstarbob]

thank you.

real pics are a ways off still. have been in the design stage of The Core Project for about 4 months now. next week i cut the final design plans/specs. it'll probably be another 6 to 9 months before it actually gets built. when we start up on it, i'll definately post some pics.

[Gravity Man]

Excellent information, but I was wondering if anyone had any info on Water Wetter?

[VashTheStampede]

You got a hold of that 40 Below Pro-Blend stuff yet rockstar?

~RT~

[r0ckstarbob]

about ProBlends 40-Below antifreeze additive

not yet. the guy was quick to pat me on the head and offer me a discount without giving me any data. while it was a nice gesture, 5 dollars off the product doesn't come close to the value of the data, or the price of a new system if it affects it adversely and blows my stuff up ya know? (not that i really think it will do that but you see my point...)

regardless, i sent another email today. hopefully will hear something back by monday, though last time he responded the next day.

as far as water wetter is concerned, most of the information i've gotten has been from their tech sheets they have on line which seem to be pretty comprehensive.

one small fact i should point out that i noticed. they made the statement that using 50% antifreeze and water reduced the heat transfer ability of water by HALF. thats not correct. it only reduces the heat transfer capacity of water by 30%, though it IS half the difference between waters efficiency and the efficiency of antifreeze. just something i noticed. now that i know what i'm looking at when i look at these numbers, actually glycol wouldn't be so bad to use if the viscocity didn't absolutely and unequivicably SUCK more then almost anything else short of peanutbutter.

anyhow, heres some good tech info on water wetter.
http://www.redlineoil.com/redlineoil/wwti.htm

the minute i get ahold of anything on ProBlends 40-Below i'll definately post something about it. maybe it's just me being a little sensitive about it but i didn't particularly like how he totally skated around me and my inquiries. we'll see if theres anything else to come back from them. failing that, we may have to resort to more stringent measures

[The Overclocker]

wow, that is amazing, i just hope you have a good cpu, or all this effort wil be for nothing

[r0ckstarbob]

thanks!!! man i've been working my butt off for a little over a month straight now just trying to compile all this accurately and cleanly


as for CPU and so forth... yup. i'm good to go.

[Arkamedies]

I wonder if we could get this made into a sticky for a month or so... it is excellent info!

[Karsta]

Thanks for kind words r0ckstarbob. You've done excellent job. I hope that that chart will be up as a sticky or in articles. (tiny note: you still have that isopropyl there - it should be 2-propanol or isopropyl alcohol)

[r0ckstarbob]

you're more then welcome. thank you for the help. will PM Hoot as to the possibility of making it a sticky or something - or might even write a small article about it basically explaining it all.

[JigPu]

Great data man!! If it wern't for the bump I might have never seen it!! One question. What does specific heat have to do with thermal transfer properties? I have had to mess with thermal conductivity before (last year in physics), but I don't remeber ever having to mess with the specific heat of substances. That was all chemestry....

JigPu

[r0ckstarbob]

well from what i've been able to gather it's this.

Specific Heat (aka Heat Capacity, Thermal Capacity) is really only relavant when held in direct comparison with the Thermal Conductivity. there is a relationship between how much thermal energy a substance can hold/store (per gram) and how much it conducts/absorbs. things like liquids (water for example) can absorb/hold more thermal energy per gram then metal (ie copper), but it conducts it (sheds it) much more poorly then copper.

the relationship between the Thermal Capacity and the Thermal Conductivity is called the Thermal Differential. the higher the Thermal Differential, the better.

in theory, the ways of improving the Thermal Differential would be to either find a way to increase the Conductivity or reduce the Capacity. using the latter method however puts more strain on your radiator and requires better flow rates as your liquid will become more sensitive to thermal changes, in either direction.

[r0ckstarbob]

graphed data comparisons


Freezing Point: (lower the better)




Thermal Capacity: The Thermal Capacity -aka specific heat- figures are used only in reference to the Thermal Conductivity and is used to find the Thermal Differential.
The Thermal Capacity is how much Thermal Energy these substances can absorb/store.




Thermal Conductivity: The Thermal Conductivity rates how quickly these substances can absorb and transmit thermal energy and generally has the most direct bearing on cooling for our purposes.
(The higher the better)




Thermal Differential: The Thermal Differential is the overall rating of the substance based upon the Thermal Capacity and the Thermal Conductivity of a substance. When it's all said and done, this is the chart/number that has to be looked at when putting the whole schebang together. This is the sum of a substances total effectiveness as a cooling medium (minus viscosity that is)
(the higher the better)

(higher the better)




This is the Kinematic Viscosity ratings of these liquids. It is measured by dropping a sphere into a bucket of liquid and measuring how quickly it reaches the bottom. It effectively measures the amount of drag upon an object passing through it and is measured in Stokes. The industrial standard is measured in Centistokes (cSt).

the lower the number = the thinner the liquid.
the thinner the liquid = the better the viscosity (for our purposes that is)
the lower the viscosity = the faster we are able to pump our coolant.
the faster we are able to pump our coolant = the more efficient our cooling mechanism.

low numbers good. high numbers bad.


The other way to measure viscosity is called the Dynamic Viscosity. Dynamic Viscosity is the measure of resistance of liquid in a tube or capillary. It's measured by pouring liquid in one end of a tube and measuring how quickly it reaches the other end. It is represented in Poise. The industrial standard uses Centipoise (cP). 1 Centipoise = .01 Poise. But as with the Kinematic Viscosity, the lower the rating the better.

http://speakeasy.net/~language/image...-viscosity.gif

the Freezing Point, the Thermal Differential, and the Viscosity are the crutial figures to look at when making your decision.

Just a note here: the term "Glycol" in all these figures is short for Ethylene Glycol Antifreeze - Prestone to be exact - using numbers from their most potent antifreeze that they supplied me upon request via email.

The term "Isopropyl" in all these figures refers to Isopropyl Alcohol (rubbing alcohol aka 2-Propanol).

Keep in mind that water is the best stuff around for heat transfer. The closer we can get our liquid to the efficiency of water, the better. Water is the standard in all these figures and the standard in which we are trying to meet or exceed (when possible) when choosing an effecient coolant.

and as always, my knowlege is far from perfect so if you see something that i missed, please feel free to backchannel me at language@speakeasy.net and we'll get it all fixed up.

[Fink]

Great job.

My only comment would be what about other glycol/water ratios and methanol/water ratios. That would be even more informative giving the user the ability to 'tune' Fp to your needs.

[r0ckstarbob]

i can do that. give me a day or two and i'll work some up.

RSB

[Hachet]

Excellent info r0ckstarbob. Thanks for taking the time to post it. I've got a question about the methanol mixture. When it's mixed w/ H20 33/66, is there any chance of this being flamable? Also are there any special considerations in terms of tubing and other gear? I ask because my father has some methanol kicking around from a hybrid vehicle he built and I happen to be building a H20 setup this week. I'm going to have a full size car radiator sitting outside and this will be piped though the siding of my house and into my room. It's already getting below freezing here at night, so I might as well take advantage of it! I also like this idea because I wont need any fans with that big of a radiator sitting outside (this is also a plus for running a system in a house that's off the grid).

Thanks again.

[r0ckstarbob]

As per request by Fink, direct comparisons between Antifreeze and Methanol at different ratios.

I should note here however that nowhere did i actually find these figures, these are figures that i extrapolated based upon the data i have compiled. it should be relatively accurate, or at least close enough to more or less predict efficiency within 5% of true.

What we're looking at here are two very comparable substances. The differences between them are often times negligible, with Methanol generally acting a little bit better then Antifreeze. Where the differences REALLY become evident is in the Viscosity. The Viscosity of Methanol is what really gives it a HUGE lead over Antifreeze from the word go; and the colder it gets, the more apparent that fact becomes. Antifreeze is most definately a great product for cars which operate at 200+ degrees where viscosity doesn't become much of an issue in that kind of heat - the heat thins it out. Methanol would be terrible in a car because of it's extremely low evaporation point. Alternately it's also why Antifreeze is going to be terrible in your computer. Viscosity becomes a BIG issue in computer cooling, especially the colder you go. With computer cooling, the vapor point doesn't often become much of an issue and we don't have much to worry about there (it doesn't take much to reduce that worry to "nil" with a decent radiator in fact). but that Viscosity, man thats the ticket. Water thins out the Antifreeze. Methanol thins out the Water... and the thinner our coolant, the faster we can pump it. the faster we can pump it, the better heat transfer we can effect. Thats how it works kiddies. The fact that it's so potent and has such a low freezing point means that we don't have to use as much of it either which keeps our water to substance ratio considerabley higher with Methanol as opposed to Antifreeze.

Antifreeze should be called Antiboil. thats where it works best and where the focus was on when they designed this stuff initally.

Antifreeze is good for HOT environments
Methanol is good for COLD environments

try to swap them out and you're going to get some really inefficient performance.

anyhow, here ya go...

Graphed data comparisons between Antifreeze and Methanol at various ratios.

Freezing Point: (Lower the better) IMPORTANT CHART




Dynamic Viscosity: (Lower the better) IMPORTANT CHART
low numbers goooood. high numbers baaad.




Thermal Differential: (Higher the better) IMPORTANT CHART




Thermal Conductivity: (Higher the better)




Thermal Capacity: (reference Thermal Differential chart)




the Freezing Point, the Thermal Differential, and the Viscosity are the crutial figures to look at when making your decision.

I'm sorry that these are all on a vertical plane. i tried to make them as easy to read as i could, but with so much information, i had to do them all vertical otherwise they'd run way off into the borders. if you have any questions, feel free to ask.

[o¢r*Aiwa]

These charts are fine, but where is the interest since Redline Water Wetter is afaik superior to all these mixtures.