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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
gs5556
1,213 posts
 
Heat sinks are rated in degrees c per watt. This means that the amount of heat dissipated is constant and that as the outside air warms, the device, too, warms to maintain the difference.

Not correct. The term degrees C per watt is the thermal resistance a heat sink requires at a given device temperature. A component will generate heat based on its intrinsic thermal conductivity and voltage/current -- which determines its operating temperature. The heat sink design needs to know this value, along with the power dissipated and the expected ambient air temperature. Then the minimum degrees C per watt can be determined for the heat sink required to maintain that temperature as a maximum. As the ambient air temp increases, the device doesn't warm -- it dissipates less heat but still enough to keep the device being cooled at or below its maximum temperature. If the ambient temperature expected is very high, then that requires a different heat sink with a lower C per watt. If the ambient is expected to be very low, then a heat sink with a higher resistance can be specified (cheaper and smaller).

The fins of a heat sink increase the surface area to transfer more heat by conduction. They also are in the path of moving ambient air. The movement of air through the fins removes more heat by convection. The heat sink designer can now factor the shape of the sink as well as the thermal conductivity. But they still transfer heat based on ambient air conditions -- the lower the ambient, the faster the removal of heat. This is the whole idea that the hp people are selling us, minus the ambient air temperature part. It is nothing more than razzle-dazzle heat sink engineering applied to the equipment chassis. My point is it doesn't work that way.
kijanki's avatar
kijanki
4,398 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
834 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
4,398 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.
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