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"The Heat Pipes are coming"... The Heat Pipes are

What is a Heat Pipe? and why you should care. A Heat Pipe( hp from hear on out)is a heat transfer mechanism that combines the principles of both thermal conductivity and phase transition to efficiently manage the transfer heat between two solid interfaces. And why should you in Audio-land care. In short the Heat Pipes (hp) transfers heat from audio equipment and audio listening rooms to make them both sound better. That's a bold statement for sure. But before you boil over and get ready to blast my post, remember there is Heat Pipe (hp) in the very computer or Laptop you are on right now. It's keeping everything in your computer cool inside so it can work as efficiently as possible. A hp contains no mechanical moving parts, and typically require no maintenance. The hp's are PASSIVE devices that are place on top of equipment and placed in your listening room. In short my dedicated listening room with sound reinforcement, diffusers, dedicated lines, and all kinds of isolation devices for my equipment. I Have never addressed the heat coming from my equipment. Since I have all solid state gear, I never thought it was necessary. But when I started putting the hp's on top of my amps near the transformer. There was a noticeable improvement. Then I did the same with my preamp near the power supply the same improvement. Then I put one on all 4 of my players, SACD,DVD-AUDIO,CD, CD 5-DISC players I was sold. The cherry on top was when I put the extra hp's around my listening room. IMPORTANT: I did not have to remove one piece of sound reinforcement when I introduce the hp's in the environment. They just make what's there work better. They look like Aluminum heat sinks with two copper tube coming out of them. I do have one that has 4 copper tubes in it, and looks to be all copper heat sinks included. I even have some that do not have any copper tubes at all , just all aluminium. The ones with the copper tube are better than the all aluminum ones everywhere I compared them at, which was everywhere. So let that Heat Pipe (hp) in your computer go to work and give me your feed back if you think like me that the "Heat Pipes are coming"... "The Heat Pipes are coming".
jejaudio
kijanki's avatar
kijanki
3,575 posts
 
"The heat sink designer can now factor the shape of the sink as well as the thermal conductivity."

Shape is already included in thermal resistance - length isn't. Extrusions are often specified in degC/W/inch.

The purpose of heat pipes is to remove heat (using liquid inside) from the location where large heatsink won't fit or operate properly (no air flow). Heat pipe connects such hot spot to external heatsink (with some temp. gradient).

Making electronics colder is not necessarily a good thing.
Main problem is to make signal path including output transistors as fast as possible to avoid delays hence TIM.
Heat makes bipolar transistors faster - a good thing (MOS gets slower with temperature - benefits from cooling). It has not much of the effect on reliability as long as junction temp is kept within reason. The only negative effect of heat is life of electrolytic caps shorten by half for each 10 degC increase.
inpepinnovations
134 posts
 
GS has it correct. The prime driver of heat is temperature difference. No delta T, no heat loss nor gain, regardless of the shape, size or material of the conductors.

The heat pipes are just a better heat transfer medium, but they won't work if there is no temperature difference, i.e. if the temperature at the 'rejection' end isn't lower than at the 'origin', then no heat transfer.

Salut, Bob P.

PS Kijanki's statements point to, however, a reason why one might hear an effect using the heat pipes, but cooling the room would also have the same affect.
sebrof's avatar
sebrof
735 posts
 
03-27-11: Jejaudio
"To Almarg: Nice spacing on your post. The conductive paste that you mentioned was on all the Heat Pipes that I have. It made no difference in sound in my system when I removed the paste with Denatured Alcohol. Another strange finding is that the Heat Pipes on Power amps sound better with the fins down on top of the transformer. But with all 4 digital players it works best with the base on top of the unit (conductive paste removed)."

To Inpep, Kijanki, Gs5556 - All good debate and theory and all, but this tells me it has nothing to do with efficient heat transfer. What it does have to do with I have no clue, but it ain't efficient heat transfer.
kijanki's avatar
kijanki
3,575 posts
 
Paste suppose to improve thermal contact since surface is never perfectly smooth (to lower case to heatsink thermal resistance).

Jejaudio said: "It's keeping everything in your computer cool inside so it can work as efficiently as possible."

It might slightly improve efficiency of computer that is mostly cmos (cooler MOS = faster = lower losses on switching) but does nothing to efficiency of typical SS amp (unless we're talking class D).

Sebrof - I don't have a clue what it does have to do with either. This is perfect example of the "Gardener's Syndrome" that makes people constantly trim, improve etc.
almarg's avatar
almarg
8,673 posts
 
Can one of you thermal experts hazard a guess that would provide some quantitative perspective on all of this?

As far as I can tell, given that he hasn't yet posted any links or photos, the OP appears to be referring to a heat-pipe based heat sink assembly that would be used on a computer cpu chip, minus the fan that would normally be attached to it in a computer application. Those things have a contact area that is in the rough vicinity of 2 square inches (around 1.4 inches on each side). Here is an example of a very good one (note that there are four photos that can be scrolled through), having more heat pipes and undoubtedly more radiating surface area than the ones the OP described. What would be your rough ballpark guess as to the reduction in semiconductor case or junction temperatures that might result from loosely placing one of these things on top of a stereo component, either an amp or a low powered component?

1 degree? 0.01 degrees? 0.00001 degrees? My guess, not having much background in thermal design, is that among those three numbers the answer would be closest to the latter.

Regards,
-- Al
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