Quick question: Will a heatpipe take damage from -5C

[nullface]

Will it? If a heatpipe is in a -5 to -15 degree enviorment will it take damage?

[Simps]

I never did that, but I can't think of a reason why should it be damaged. I think the answer is no, but you should wait for others with more experience on this to reply.

[fatguy1992]

I'v never heard of it happening.

@Simps

The reason y it might take damage is cause the metal would shrink and may break away from certain parts. Thats just my guess.

[Simps]

I'v never heard of it happening.

@Simps

The reason y it might take damage is cause the metal would shrink and may break away from certain parts. Thats just my guess.

Well thought. Could be a reason, yes.

[STEvil]

No worries about metal shrinking, only problem may be the liquid inside expanding because that is what water does when it freezes.

[nullface]

No worries about metal shrinking, only problem may be the liquid inside expanding because that is what water does when it freezes.

That was what i thougt.

[Simps]

What liquid is that on the heatpipe? I don't get it...

[ownage]

What liquid is that on the heatpipe? I don't get it...

A heatpipe should have liquid in it that moves the heat. My experience is that most heatpipes are not filled, and just empty? :shrug:

[Simps]

A heatpipe should have liquid in it that moves the heat. My experience is that most heatpipes are not filled, and just empty? :shrug:

OMG! How come I have never heard about this? So, there should be liquid inside my asus heatpipe? I don't know why, but I just don't believe there is :(

Have someone cut the pipes to see if there were anything there?

[Planet]

Most of the time its a vapor so you cant really see if there was anything.

[ownage]

I've cut a few heatpipes. Some from laptop's, some from motherboards, and a CPU heatsink. All empty.

I really don't think heatpipes will damage from cold.

[nullface]

Im sure they were not empty, as said befor its a vapor, so if you open it it might just all be in gas form (right?).

[roofsniper]

Im sure they were not empty, as said befor its a vapor, so if you open it it might just all be in gas form (right?).

if it was a liquid you would know it. the center of gravity would change whenever you leaned it one way, it could make sounds, you would be able to tell. im pretty sure it wouldn't take damage at -5C theres plenty of guys that have done ln2 on boards that have heatpipes on them and im pretty sure it is freezing around the mobo area. what are you planning to do anyway?

[jdmR]

2 things could happen. the metal becomes harder when its cold, meaning it also becomes more brittle. the way for liquid to form within the pipes itself is if there is hydrogen gas and oxygen and somehow some kind of energy to bond them together to make water than form ice (most unlikely). -5c should be fine as long you dont chip metal as it becomes more brittle

[cegras]

The working fluid in the heatpipe is set up under a certain pressure such that any sort of heat will readily vapourize it.

[fatguy1992]

WOW I didn't know there was anything inside the heat pipes :shocked:

[Simps]

Me too. But for some reason, I still believe there is nothing inside it really. It's hard to believe there is any kind of liquid there, and it is actually not a good idea to have air there, since heatpipes can go up to 90C, and you know the air there would just go crazy bad @ 90C. Really, I just think mobo heatpipes are empty, when they are not solid, but I could be very wrong =/

[jdmR]

im leaning more on the said that there is no liquid in there either.

[STEvil]

Me too. But for some reason, I still believe there is nothing inside it really. It's hard to believe there is any kind of liquid there, and it is actually not a good idea to have air there, since heatpipes can go up to 90C, and you know the air there would just go crazy bad @ 90C. Really, I just think mobo heatpipes are empty, when they are not solid, but I could be very wrong =/

Thats the entire point.

The heat excites the liquid/vapor inside making the molecules crash into everything to transfer the heat energy towards the coolest point of the heatpipe (where the heatsink fins are).

[roofsniper]

why would they just put air in there? it wouldn't have any effect at all.

[Simps]

Thats the entire point.

The heat excites the liquid/vapor inside making the molecules crash into everything to transfer the heat energy towards the coolest point of the heatpipe (where the heatsink fins are).

Makes sense. But what is there inside? Liquid, or vapor? I am still clueless LOL!

[fatguy1992]

Thats the entire point.

The heat excites the liquid/vapor inside making the molecules crash into everything to transfer the heat energy towards the coolest point of the heatpipe (where the heatsink fins are).

That makes a lot more sense to me now :).

[BababooeyHTJ]

I thought the whole point of putting a liquid into the heatpipe was because the liquid would heatup and vaporize at the hottest point of the heatpipe, at the block, and travel to the coolest point where the fins meet the heatpipe then condensate falling back to the hottest point and repeating the cycle, therefore moveing more heat. What exactly is in these things? :shrug:

[Polizei]

It's usually water or mercury inside a heatpipe (according to wikipedia). The heatpipes are under a vacuum inside, meaning water will boil at less than 212F/100C. They are probably under such a vacuum that the water will boil at 50C or lower.

The way a heatpipe works is, the liquid boils at the heatsource (processor, chipset), and the vapor flows to the cooler parts (fins) where it condenses, and is then wicked back to the hot area via a wicking material inside the pipe.

[Simps]

It's usually water or mercury inside a heatpipe (according to wikipedia). The heatpipes are under a vacuum inside, meaning water will boil at less than 212F/100C. They are probably under such a vacuum that the water will boil at 50C or lower.

The way a heatpipe works is, the liquid boils at the heatsource (processor, chipset), and the vapor flows to the cooler parts (fins) where it condenses, and is then wicked back to the hot area via a wicking material inside the pipe.

Ok, but how come when people cut a heatpipe from a mobo in half, when the mobo is off, and the heatpipe temps = ambient = 25C for example, they see no liquid inside?

I bet mobo manufactors don't put anything inside that heatpipe thing.

[STEvil]

because there is often very little or it has soaked into the wicking material

[jdmR]

i think the only way to really find out is if we ask the manufacturers themselves.

[m0da]

heatpipes aren't a big conspiracy theory...
the liquid/vapor is really there! trust STEvil at least

[biohead]

Ok, but how come when people cut a heatpipe from a mobo in half, when the mobo is off, and the heatpipe temps = ambient = 25C for example, they see no liquid inside?

I bet mobo manufactors don't put anything inside that heatpipe thing.

if heatpipes were empty, we would be idling at 60 degrees celcius. trust me, and stevil knows his stuff, too.

when you cut a heatpipe open, the pressure changes, but besides that, the little bit of liquid or gas will easily dissolve in the air available.

[Razor_Blade]

I should also add, if there was a non-water liquid in heatpipes, it wouldn't matter if it froze. Water is among a list of very few things that expand when they change from liquid to solid phase.

[Polizei]

Ok, but how come when people cut a heatpipe from a mobo in half, when the mobo is off, and the heatpipe temps = ambient = 25C for example, they see no liquid inside?

I bet mobo manufactors don't put anything inside that heatpipe thing.

What conspiracy theory is there? Do you believe that the moon landings were fake, and that they were filmed in the desert in Arizona? Do you think Kennedy was capped from the grassy knoll? Do you think umpires really conspire to keep the Chicago Cubs from winning a World Series?

There is liquid in a heatpipe. Trust me.

[Simps]

What conspiracy theory is there? Do you believe that the moon landings were fake, and that they were filmed in the desert in Arizona? Do you think Kennedy was capped from the grassy knoll? Do you think umpires really conspire to keep the Chicago Cubs from winning a World Series?

There is liquid in a heatpipe. Trust me.

Yeah my bad. I just saw JFK from Oliver Stone these days, and looks like I became a bit crazy about conspiracy LOL...

You are right, there is probably liquid there, lets hope so LOL!

[Calmatory]

Honestly, people thought that heatpipes were just hollow copper pipes? Now how would that transfer heat so well? :p: Back to school, pepple!

The amount of the liquid is VERY small, like 100th of a droplet for 10 cm of a heatpipe if not less, now try to see that when you cut a heatpipe. :p:

[Deodatus]

Firstly, you should know some basic physics concerning heat transfer, found here (http://en.wikipedia.org/wiki/Heat_transfer).
So, there are three ways for heat to go from A to B.
1: Conduction
2: Convection
3: Radiation

Now if the heatpipes were vacuum they would not work because they would have to rely solely on radiation and conduction, making them worse then a solid copper bar, which would at least have a proper heat conduction.

If there were air inside, they would still be worse then a solid copper bar, because air does not conduct heat even remotely as well as copper does.

So, do manufacturers only use heatpipes to save the cost of the copper that makes the difference between a pipe and a solid bar? No. They use heatpipes for a reason, as already pointed out in many posts above me.

There is fluid in the heatpipes, albeit very little. Why only so little then? Less fluid means the overall temperature of the fluid rises quicker, making the evaporation cycle quicker. This means that the heatpipe functions at a lower temperature then it would with more fluid.
Not sure whether this (http://en.wikipedia.org/wiki/Heatpipe) link has been posted already, but it surely explains the heatpipe well.

As for the original question, a heatpipe will not take damage from -5C.
Firstly because there is only so little fluid, that even if it would all freeze, it would not damage the pipe, only affect the cooling capacity of your heatsink.
Secondly, it won't freeze because it is not water used. There are better fluids/gasses to conduct heat then water and they usually freeze only well below -5C.
Thirdly, even if it were water (which it is not), even the water would not freeze because it is under a far lower pressure then normal.

So, you can safely use heatpipes under zero.

[Calmatory]

It would be nice to see how the cooling performance fluctuates with the ambient temperature. E.g. from -20C to +50C and compare the temperature delta between the CPU temperature and ambient temperature. Also measure top-of-heatpipe temperature and heatsink base temperature and take delta from there.