you mean on the 7000cu?Quote:
Originally Posted by craig588
i know, but it stil lhas a terrible sound at 50cf(over 40dba), but here at xtremesystems it won't be called loud.
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you mean on the 7000cu?Quote:
Originally Posted by craig588
i know, but it stil lhas a terrible sound at 50cf(over 40dba), but here at xtremesystems it won't be called loud.
Indeed, the capacity of the sealed system is unchanging.Quote:
Originally Posted by craig588
But when not in action, that volume will be at low pressure (wherein the majority of the contents will be liquid)and at high temps, it'll be at high pressure (wherein the majority will be gaseous).
Volume remains the same while pressure changes.
You are not making any sense. Lower pressures make something a gas, higher pressures make them a liquid. If there is space in that tube not filled with something and there is liquid R134a in it it won't just remain a liquid at room temperature, it will expand to fit the whole tube because there is less pressure because it has a greater volume. A gas will never just remain a liquid if it is in conditions where it is capable of being a gas. (Nor will it remain a gas if it is in conditions that allow it to turn into a liquid)
If you mean the whole tube is filled with R134 to a point where the whole thing is liquid than the heatpipe truely is worthless.
If your room temp was -18C then it would turn into a liquid when cold, but defintly not under normal operating conditions.
Craig, imagine a sealed chamber half full of liquid - the other half is its gaseous form, lets say at one atmosphere.
If we apply heat, the liquid will start to gasify and the pressure will increase.
You're saying that the increasing gas pressure will prevent the liquid from gasifying - but in the RW, that doesn't happen.
Correct me if I'm barking up the wrong tree.
Assuming too much, everyone does it differently.Quote:
But it's not filled entirely with liquid.
The Gas has a low specific heat capacity, any benifit of faster transfer away from the energy generating source is useless. The liquid form does not fill the entire pipe depending on the construction, and I dont know of many liquids that can conduct heat as fast as copper... granted i've not looked deeply into that.Quote:
Sure, but there's a combination of gaseous transfer and solid conduction up the pipe.
agreed on heatpipe design, but what the heatsink manufacturer choses to put into and how much is up to them.Quote:
Edit: I spent too long typing, this is supposed to be in response to STs post.
120mm fans fit perfectly on 7000's ;)
Increased pressure increases liquid to gas transfer speeds in water (pressure cooker) and expands the water molecules. If this holds true for all liquid to gas transfers I dont know, however.
That can't happen. The liquid part will turn into a gas and equilize with the rest of the R134. It will never stay a liquid unless it doesn't have the chance to turn into a gas and the only way that will happen is if the entire tube is liquid, but at that point it won't perform any better than a solid copper tube.Quote:
Originally Posted by Y.H.Pats
Now if Asetek said that their heatpipe is a mixture of a few different things then your theory would work, but they said it just uses 27G of R134.
Gas and liquid at the same time?
Sure it can.
EDIT
Example:
When you boil water it does not all flash suddenly to a vapor, even if you superheat it them disturb it. The whole of what is inside the heatpipe does not change phase all at in one instant.
But there appears to be a capillary-throttle on this thing - which points towards a liquid to gas transition.
You say Asetek said it only contains R-134 ... how is that incompatible with phase change ?
What else would you expect to be in the system ?
My sealed chamber scenario was purely for the point of demonstrating the pressure-phase relationship.
Ok, I belive I understand it, I always figured that if there was liquid and gas in the tube that the liquid would become a gas to reach equilibrium, but I didn't take into account the pressure that the gas on top is pushing onto the liquid. you increase the pressure on the gas through increased temps and volume of the liquid, it liquifys the gas in the top and the cycle repeats.
When it is a liquid it shouldn't be terrible at absorbing heat like it would have if it was a gas.
Now if only a company made a vertical heatpipe system.
I see where the confusion was arising, Craig.
Lower pressures will make more gas, but only where the gas is of one chemical dissolved in the liquid of another, eg - CO-2 in water.
heh yeah,Quote:
Originally Posted by ZeroHero
(anywhere else) quiet = less than 23dBa
At Xtreme quiet = less than like 50dBa :ROTF:
I actually thought that heatpipes used just oil and no gas in them ? The oil is heated at the bottom of the tube near the cpu and convection causes a rising- cooling - descending cycle which transfers heat away from the bottom ??
Have I got it all wrong ? :) Won;t be the first time....
Regards
Andy
Depends on the manufacturer, zakelwe.