Water Cooling

[GRollins]

Water cooling is easy and very efficient. I started a thread on this once upon a time reporting on a water cooled Aleph 2 I'd built. I later added another pair of Aleph 2s to the same water cooling system. The temperature at the devices is somewhere around 105 degrees F, if I recall correctly. Until you've tried it, you'll have trouble believing how much heat you can remove. It's also cheap. The only downside really is that the amps are no longer portable in the sense that air cooled ones are.

Grey

[falcott]

I wonder how a passive system would work, like the "thermo-syphon" cooling system in the Model T Ford (and old stationary engines). I think it runs a little hotter than a pump system, but would it cool well enough? And how could we estimate the volume of water needed, and/or the surface area of the radiator?

[imix500]

Do you guys know of a good source for those large surface area "water blocks"? I havn't had much luck locating surplus, and I bet they're pricey new.

[akira]

Well, the cheapest way to go is to get some pieces of copper or aluminium, drill several holes and solder tubes on it. Electronic suppliers are selling large waterblock for a very high price and they won t be better than a diy WB.

[GRollins]

I believe you'll find that my way is cheaper if you plan to use more than one or two devices.

Grey

[alaskanaudio]

I have also been thinking about water-cooling around for a while. With two class A amplifiers running that suck down 600 watts of AC power each it does not take long to make a listening room a little to warm for comfort, even in winter here. As a result I have seriously thought about designing a class AB amps, or perhaps even trying my hand at a class D. Perhaps doing this will make me more environmentally friendly.

I go along with Grey’s suggestion that soldering copper tubes to the back of a nice thick copper plate is the best way to go. I would use soft metal tubes that could be bent into 180-degree bends to zigzag back and forth on the rear of the plate. A proper bending tool would need to be made and used to keep the tube from collapsing when being bent.

Soldering the tubes to the back of the metal plate can easily be done on a stove in the kitchen if nothing else is available. I have seen this done in the past for high power RF amplifiers and it does indeed work very well. There would likely have to be two heat exchangers built, one for the work bench and the other for the listening room. Water cooled heatsinks would allow the amplifiers to fit into a much smaller enclosure.

Johannes

[kilowattski]

Why not get a pair of conventional heatsinks and two 6" by 6" copper blocks. Drill two holes lenghtwise in the copper block about 4 inches apart. The hole size should be slightly larger than the diameter of copper tubing youn plan to use. Take a length and make a 4" loop. Solder the loop to one end of the copper block and two straight tubes to the other end. Solder a couple of fittings to the other end of the straight tubes. Put some thermal goo on the copper block and bolt it to your heatsink. Mount the block to your heatsink. Mount your transistors to the copper block. If I am correct the block will act as a heat spreader for the conventional heatsink and also as a watercooled heatsink itself. Because of the combination of the two heatsinks the copper water cooler you just built would not have to work as hard and one of those new passive radiators for computer water cooling could be used. It's noiseless, efficient and easy to implement. See diagram below.

[Brian Donaldson]

You can get a radiator from a 3/4 ton truck and put in another room or attic. It'll dissapate 4 or 5 KW without any trouble with a cheap elecric box fan.

Or if that's a little too big, try www.jcwtruck.com and get an http://www.jcwhitney.com/autoparts/P.../p-322/c-10614 automatic transmission fluid cooler.

[GRollins]

Although putting a serpentine copper pipe along the back of a copper plate would work wonders, I've yet to outstrip the heat-carrying capability of ordinary 1/2" copper pipe soldered to the thin edge of a 1" x 1/4" copper bar, thus: --O The devices mount to the wide side of the copper bar. Cheap, easy, efficient, and if you polish the copper nicely it looks pretty sexy.
I'm not saying that all these high fiddle-factor ideas won't work--it's just that you can get excellent results with a whole lot less effort. Water cooled systems are so effective it'll scare you.

Grey

[highbias]

"A proper bending tool would need to be made and used to keep the tube from collapsing when being bent."

That can easily be accomplished by filling the copper tubing with low melting point Bismuth metals of the type used in sprinkler heads. After you've filled the tubing with the special metal and made the bend just heat up the tubing to recover the metal and use it to full the next pipe then bend and so on down the line. This way no bender is needed, just a simple jig to keep them all the same. I used this method once when I built a scale model steam locomotive and it works beautifully!! The low melting point metals are available from Small Parts Inc in Miami.

I am still contemplating doing what Kilowattski mentioned except I am not planning on soldering tubing into my copper plate. I will just drill and tap the holes for small copper fittings that will be silver soldered to make them leak tight. This way simple flexible tubing can be used to join the cooling system together. Ia lso feelt hat with water being in direct contact with the copper plate will increase the efficiency quite a bit.

Mark