Heatsinks...today's relevance????

[Reeler]

When my Japanese amps were made (1982-84) the Japanese introduced a cooling system based, not on massive fins but, on liquid cooling pipes.

These fell out of fashion until the boom years of silent computers.

Now the "GO" seems to be liquid cooling on game computers.

Are we slow to catch up on this " liquid cooling" phenomenen or do we just dismiss liquid cooling because it doesn't look nice?

a lot of investigation and progression has gone into liquid cooling yet we hi-fi guys seem to think that it is not hi-fi.

I have many wishful hi-fi projects going at the moment, my main one is based on liquid cooling pipes. I don't want intrusive "Fan Cooling" [noise] but I believe it is time to utilize what the computer guys have discovered.

I ventilate my room according to Class A heat.
Static liquid cooling, [not needing a pump system], has its place in transistor Class A audio.

Discuss!

Reeler

[BobEllis]

Like their plumbing counterparts do with water, all heat pipes do is move heat. Useful in applications like laptop computers when you can't mount the heat sink directly to the processor, but at the other end of the pipe is still a heat sink of some sort. Before computers made them affordable, heat pipes were often used in high power military and space applications.

There have been plenty of liquid cooled projects here for those who want to put the heat somewhere outside their listening room and use a relatively small heat exchanger with a fan.

IMO, it is less about whether liquid cooling is hi-fi than it is about not needing it because we can mount the devices that need cooling directly to the heat sinks and avoid the complication, expense and added potential failure modes of liquid cooling or heat pipes.

[Reeler]

But you agree that everything, to the acceptable teenagers, is about being smaller?

Even in a home-cinema setup with 5 to 7 amps the best bet is to have a quiet cooling system based on "freon" or other refrigerated cooling "static" pipes rather than the heat being taken away by a pump system? Based on a refrigerator.

The sealed copper pipe is more advantageous than the noise of a pump system.

[sawreyrw]

About the maximum power density that be handled with forced air cooling is 50 watt/sq. in. of area of the device dissipating the power. If you go above 50 watts/sq. in. you need to use liquid cooling or possibly heat pipes.

[BobEllis]

The heat has to go somewhere. If you are going to dump 100W it takes a certain amount of surface area or airflow. Heat pipes have allowed higher power densities by enabling heat to be removed from a small area with no airflow and moved to another area that is better able to dissipate heat.

In reality, you will need BIGGER heat sinks to keep the same device junction temperature (the only thing that matters) when you add the thermal resistance (temperature difference required to make the heat pipe work) of the heat pipe.

Take a look at ::: Zalman, leading the world of Quiet Computing Solutions ::: The reason that this CPU cooler can be quieter than one with fins mounted directly to a CPU is that the pipes allow more effective heat transfer to a larger surface area radiator and fan speed can be reduced. It certainly is not smaller.

Another way of doing the same thing is use a thick pad of material with a high thermal conductivity. A slab of copper would work, but would be heavy and more expensive. There are lightweight materials with even better thermal conductivity than copper used in aerospace and high power density applications such as http://www.advceramics.com/downloads...ents/85504.pdf

Sure, a heat pipe is quieter than a pump and fan cooled heat exchanger, but unless your design requires mounting the high power devices in tight proximity or you are dumping the heat to another room, I don't see any advantage to using heat pipes in an audio application.

With Gaming computers the reason for liquid cooling is power density, and a bit of "cool" factor - It's so hot it requires liquid cooling adds a bit of bragging rights.

[Reeler]

Thank you Bob,
I find your mathmatics of good value.

I want to put at least 5 of these amps on one wooden structure.....to service a home cinema setup.

Only two of these amps will be operating on Class A. (60-240w)
The others will be on class AB 600w....less heat.

As a retired 51yr old in retirement I am finding an undiscovered talent for mathmatics I am at your service.

[BobEllis]

Dissipating 500W+ in one chassis? That's lots of heat sink area. You might want to rethink your setup considering splitting it into a few pieces. Conrad's MF35-151.5 can safely dissipate 120W or so, to give you some idea.

A little bit of fan induced airflow can help a lot and not be intrusive. A slow moving fan buried inside a wooden enclosure blowing out through the heat sinks can be surprisingly un-noticeable.

[niko084]

The heatpipe design is to get the heat off the chip and onto the fins which disperse the heat. In pc's this is very important mainly due to overclocking, you have a direct piece of equipment with a limited amount of space for a heatsink in who knows what case, area's around the cpu also need to be cooled. This is all generally designed around stock usage, in cpu's the power consumption can nearly double when overclocked. Not to mention it just gets heat off faster, you still need the large fin array to actually cool, or a fan, again electric motor, noise, something to fail.

Full on water cooling where you have a pump, water block and heat exchanger *radiator* is great but then you have noise from the pump, if that's near your equipment you can expect noise introduction being it's a fast spinning electric motor, let alone space for the exchanger and fans *if it needs them* plus the worry of a water leak... All around it's kept to the enthusiasts even in computers for good reason.

Large manufacturers are on a fine balance between quality, price, reliability etc... The standard industrial style heatsinks are cheap, plain and simple, they also work and when used properly they don't require any fans, less dust, less noise.

Overall I greatly prefer completely passive cooling, it's silent and it just works. I don't expect to see any new AV receivers on the market today which are fan cooled to be working like new in 20 years like my old solid state equipment, not without at least replacing that fan a few times, maybe more.

[Reeler]

Bob, you are on my line of thinking.

When I make Spagettii Bol. or boil potatoes for the kids I stand over the heating plates and wonder why this heat has to be sucked up through the ventilation shaft. By God, I could dissapate this heat by another means.

My background is in thermo-energy.

I have already devised "quiet music" in the countryside. I am just looking at ways to introduce this to the city-folk.

[BobEllis]

I figured that you'd be cooking paella in Barcelona. It's one of my favorite dishes, discovered on a Navy visit to Palma de Mallorca. Perfect after a long bicycle ride along the southwest coast to La Calobra and back

I hated thermodynamics in college but ended up selling vapor cycle and liquid cooling systems for radars other high powered electronics for a while. I was trying to sell liquid cooled SEM-E and VME cards when I ran into the TC1050 material linked to above. Two fewer potential leak paths, so they got that part. I got most of the rest of the cooling system, though.