Best Coolant Of All?

[Daniel Johnson]

Ok, so I'm getting mixed signals about this from dozens of different websites and hundreds of different comments/threads.

What really is the best coolant?
Now I know pure water is incredibly hard to beat, but I also know that everyone swears by there own combobulated mixture of god knows what.
Some say distilled water
Some say deionized water
Some say straight glycol
Some say 50/50 glycol-distilled
Some say pre-mixed coolants
Some say distilled water with 5% Water Wetter
Some say 50 distilled/50 water wetter

People say use glycol because it is basically antifreeze and it must be the best because they use it in cars. But is that really true? Isn't antifreeze used in place of water simply to prevent freezing during the winter and to lubricate parts?
It doesn't mean that it has a high thermal conductivity, but it is high enough for cooling a car.

A quote for water wetter is:
"Red Line's unique Water Wetter® reduces the surface tension of water by a factor of two, which means that much smaller vapor bubbles will be formed. Vapor bubbles on the metal surface create an insulating layer which impedes heat transfer. Releasing these vapor bubbles from the metal surface can improve the heat transfer properties."
How true does this sound? It's probably just a marketing scam...or is it? I have no idea to be honest.

Other people say that if you use deionized water it's perfect because it's the purest and least conductive liquid on the face of the earth. However, is that really true? Because I've read that it dissolves the metal components in your water loop, therefore gaining ions, and becoming acidic, ionized, and conductive, which sounds pretty bad.
But how can gaining ions do all of that? Wouldn't it just become the same as distilled water then? And surely distilled water isn't acidic....is it?

And I've also read that straight distilled water has the highest thermal conductivity of virtually any liquid, which is true, and that it has the easiest clean up if a leak springs. But again, what about that "killer acid distilled water"?

Where are the benchmarks for coolants? I can't find any!

So what really is best?

I'm going insane trying to find a definitive answer here, help me out.
Thanks so much

 

[Deuce65]

There are very few actual tests done because there isn't much need to test. Cooling capacity is strictly a function of the heat capacity of the liquid in question; there are very few substances with a better heat capacity then water and none of them are things you want in your loop (mercury for example) or ridiculously expensive (1k plus a gallon).

Adding things with a worse heat capacity then water cannot physically improve your performance, it is not physically possible. On the other hand, taking a bottle of water and selling it for 20 dollars is quite profitable, hence all the marketing.
Distilled water is selected over tap water simply because it doesn't have the nasty minerals in it that gunk things up.
Deonized water is pointless because it only stays deonized for a couple days at most.
Biocides are not strictly needed with distilled water but if desired, can be a few drops of poison like PT nuke, or a silver plug or coil.
Anti-corrosives are usually not needed with distilled water because it plays nice with copper, which most blocks these days are made of; the exception would be if you are using corrosive combinations like copper and aluminum.
Anti freeze is obviously not needed unless you plan on running your machine below freezing.
Water wetter and the like are not needed because water temperatures never come even remotely close to the temps that will result in vapor bubbles (if they do, you have much bigger problems to deal with).
In short, none of these compounds offer any benefits to justify paying a premium for them and in fact can be quite harmful (acrylic for example responds quite negatively to many of them).

Here is one of the few tests published:

http://skinneelabs.com/coolant-fluid-roundup-thermal-performance/3/

You can see there is no performance gain from any of these compounds, just as we would expect.

 

[rdc85]

It deepends on what you means "the best",

For me the the best one is the easiest to use, safe for the loop, things like low maintenance..
Not care for few deg difference, since don't push O.C. hard..

I buy pre-mixed coolant.. (pricier but easy to use)

edit: maybe I just lazy haha..
I used Koolance LIQ-705.. (LIQ-702 also an option)

 

[Daniel Johnson]

There are very few actual tests done because there isn't much need to test. Cooling capacity is strictly a function of the heat capacity of the liquid in question; there are very few substances with a better heat capacity then water and none of them are things you want in your loop (mercury for example) or ridiculously expensive (1k plus a gallon).

Adding things with a worse heat capacity then water cannot physically improve your performance, it is not physically possible. On the other hand, taking a bottle of water and selling it for 20 dollars is quite profitable, hence all the marketing.
Distilled water is selected over tap water simply because it doesn't have the nasty minerals in it that gunk things up.
Deonized water is pointless because it only stays deonized for a couple days at most.
Biocides are not strictly needed with distilled water but if desired, can be a few drops of poison like PT nuke, or a silver plug or coil.
Anti-corrosives are usually not needed with distilled water because it plays nice with copper, which most blocks these days are made of; the exception would be if you are using corrosive combinations like copper and aluminum.
Anti freeze is obviously not needed unless you plan on running your machine below freezing.
Water wetter and the like are not needed because water temperatures never come even remotely close to the temps that will result in vapor bubbles (if they do, you have much bigger problems to deal with).
In short, none of these compounds offer any benefits to justify paying a premium for them and in fact can be quite harmful (acrylic for example responds quite negatively to many of them).

Here is one of the few tests published:

http://skinneelabs.com/coolant-fluid-roundup-thermal-performance/3/

You can see there is no performance gain from any of these compounds, just as we would expect.

Ok, well I'm not sure if I'll be able to reach 0C or not. I'm planning on cooling a i7-5960X @ TDP of 140 watts, 4-way SLI EVGA Titan X Superclocked @ TDP of 250 watts each, and 8x4GB Corsair Dominator Platinum 3000MHz @ 1.2V (watts unknown), plus a single pump, making for a rough estimate of around 1200 watts and using 2, Koolance EXC-800 Portable 800W Recirculating Liquid Chillers to do this cooling in a dual loop.

Combined, they intake 900 watts and unleash 1600 watts of cooling power, using refridgerant R-134a. All other system components will be air-cooled inside a HAF X case via 4, 166.2CFM 200mm fans and 1, 90.3 CFM 140mm fan. I'm hoping this would be enough to achieve near-freezing temps, if not sub-zero temps.

It deepends on what you means "the best",

For me the the best one is the easiest to use, safe for the loop, things like low maintenance..
Not care for few deg difference, since don't push O.C. hard..

I buy pre-mixed coolant.. (pricier but easy to use)

edit: maybe I just lazy haha..
I used Koolance LIQ-705.. (LIQ-702 also an option)

I mean best for cooling. However, I'm not worried about 0.1C or 0.2C lower, if it means a possibilty of destroying my system via gunk or is difficult to clean.

 

[Daniel Johnson]

Is the walmart brand distilled water for $0.88USD per gallon "as good" as what I can buy from amazon or other places for higher prices or not

 

[Deuce65]

Is the walmart brand distilled water for $0.88USD per gallon "as good" as what I can buy from amazon or other places for higher prices or not

Yes.

 

[palladin9479]

Distilled water with a silver kill coil is probably "the best" as far as being safe, easy to use and efficient. Deuce65 has already done a very good job of explaining why additives aren't needed and can actually be harmful to your system. The only way to get your loop under ambient is phase change, peltier or some other exotic method which brings out a whole new set of problems you need to find solutions to.