Heat Pipe vs Water in a Tube: Thermodynamics Experts Welcome

[nycesquire]

Which can move heat faster: a few heat pipes (say six 6mm pipes) or water running through a tube?

Careful: I'm trying to zero in not on whether a heat pipe setup or a water cooling setup is better for any particular application, but whether (i) water flow through a tube or (ii) a heat pipe (say sintered, for example) is better at moving heat to a heat dissipating device (whether the heat sink is a radiator, a heat sink or something else entirely).  Let's assume the same size heat sink, radiator, etc.

My hunch is that all of these complex and blingy water cooling setups (pumps! fittings! reservoirs!) don't accomplish much more than a heat pipe system would.  If they don't, and they are just fun for funsies sake: Great! A watercooled loop looks awesome and is fun to build.  Enough for me!  I just don't want to delude myself on the actual performance.

What does the science say?

[desertcomputer]

Science say it the difference is really really small. 

[niofalpha]

Fittings, pumps, and reservoirs don't effect temps by any noticeable margin in 90% of all scenarios. 

Water is far more efficient at transferring heat that most metals tho, so that's why it's usually better.

[thekeemo]

Heatpipes have vapour in them

The benefit of watercooling is that you get alot of surface area outside of the box where heat gets trapped

[pagani123]

1 minute ago, thekeemo said:

Heatpipes have vapour in them

technically they have both just at different temperatures.

[pagani123]

i would say a special type of heat pipe called a vapor chamber has the most efficient heat transfer as it takes a lot of heat to boil a liquid (under a semi vacuum). now whether that would cool the computer quicker i am not sure as the vapor chambers would be connected to sheets of aluminum or copper which would loose efficiency.

[Stefan1024]

Heat pipes are better for short distances, but watercooling does scale better with length. Sure you need a more powerful pump but the cooler performance is not different if the pipe is 0.1 of 5 meter.

But the heat pipes can run dry on the hot end if the transportation inside the heat pipe is not sufficient due to the length.

 

[nycesquire]

Thanks to all of you for your input.  Stefan1024, can you expand on your response?  At what lengths does heat pipe performance start to drop, for example, ~75c?

[Stefan1024]

This depends on a LOT of facors and require spcific data and a calculation. But I estiamte watercooling takes the advantage for pipes longer than 20cm.

just look up the data sheepts of a heat pipe model with different lengh so see the difference.