water cooling
I have a pretty good background with homegrown computer water cooling. My Athlon XP 1600+ is water cooled right next to my feet here.
I can give you some ideas on how it was implemented, I may have some pictures to link to as well.
http://nnytech.net/~format/imgs/waterblock.JPG
This is the waterblock that sits on the CPU. It weighs about 2 pounds and has a zig-zag path for the water on the inside. The copper cost about 8USD and I did the crappy job milling at highschool a year ago for free.
What you could do for an amplifier where you have to cool a row of items is use square channel aluminum
<http://onlinemetals.com/merchant.cfm?id=69&step=2>
You would have to make plugs for the ends and clamps to hold the devices down. The ideal clamping pressure would be about 15-20 pounds per device to get the best thermal conduction. If you don't need to isolate the devices on each square rail, using a thermal compound like Arctic Silver without mica insulators is necessary to get the best performance.
For a pump, I use one that I got from a pet store for a large aquarium, it pumps a lot of water [more than necessary even for a large system]
The reservoir is made of two 4" ABS pipe end caps glued together. Now is a good point to mention that a convection-only system would let the devices get fairly hot before the water moved. Also, the system would have to be a completely closed loop or the water would boil away from the heat source and not be replaced. However you can not have a closed system without things becoming pressurized when the water heated up.
I'm a little scared of pressurized water near expensive equipment, much less very low pressure water like the pump system I'm using.
For the radiator, I'm using a heater-core that was 25USD. It is designed for a Ford truck and is probably one of the most common sizes available so it is low cost. Paint it black and it isn't even that ugly.
I used distilled water because I don't want things growing in my pump lines such as mineral crystals. I added a small amount of methanol to keep algae or anything from growing in it. Methanol also lowers the surface tension and increases the cooling ability of the water, so I'm told...
All this being said, water cooling is nice but requires maintenance. You would want to check the water level often, inspect the hose barbs to make sure the tubing is staying put, etc.
Remember the water block image? Imagine how much heat would be required to melt the solder out of that. Well it happened when I had a speed control on my pump to make it more quiet. The pump quit because the speed was set too low and it boiled all the water out of the water block, and cooked my processor and melted the solder out of the block.
My water cooling system would cost someone about $75 US to build. Fortunately for an amplifier, a thermister could keep track of the temperature and shut the amp down if the temp got too high.
I have some experience with peltier devices too, but I don't think that is relevant to audio amplifiers.
I have a pretty good background with homegrown computer water cooling. My Athlon XP 1600+ is water cooled right next to my feet here.
I can give you some ideas on how it was implemented, I may have some pictures to link to as well.
http://nnytech.net/~format/imgs/waterblock.JPG
This is the waterblock that sits on the CPU. It weighs about 2 pounds and has a zig-zag path for the water on the inside. The copper cost about 8USD and I did the crappy job milling at highschool a year ago for free.
What you could do for an amplifier where you have to cool a row of items is use square channel aluminum
<http://onlinemetals.com/merchant.cfm?id=69&step=2>
You would have to make plugs for the ends and clamps to hold the devices down. The ideal clamping pressure would be about 15-20 pounds per device to get the best thermal conduction. If you don't need to isolate the devices on each square rail, using a thermal compound like Arctic Silver without mica insulators is necessary to get the best performance.
For a pump, I use one that I got from a pet store for a large aquarium, it pumps a lot of water [more than necessary even for a large system]
The reservoir is made of two 4" ABS pipe end caps glued together. Now is a good point to mention that a convection-only system would let the devices get fairly hot before the water moved. Also, the system would have to be a completely closed loop or the water would boil away from the heat source and not be replaced. However you can not have a closed system without things becoming pressurized when the water heated up.
I'm a little scared of pressurized water near expensive equipment, much less very low pressure water like the pump system I'm using.
For the radiator, I'm using a heater-core that was 25USD. It is designed for a Ford truck and is probably one of the most common sizes available so it is low cost. Paint it black and it isn't even that ugly.
I used distilled water because I don't want things growing in my pump lines such as mineral crystals. I added a small amount of methanol to keep algae or anything from growing in it. Methanol also lowers the surface tension and increases the cooling ability of the water, so I'm told...
All this being said, water cooling is nice but requires maintenance. You would want to check the water level often, inspect the hose barbs to make sure the tubing is staying put, etc.
Remember the water block image? Imagine how much heat would be required to melt the solder out of that. Well it happened when I had a speed control on my pump to make it more quiet. The pump quit because the speed was set too low and it boiled all the water out of the water block, and cooked my processor and melted the solder out of the block.
My water cooling system would cost someone about $75 US to build. Fortunately for an amplifier, a thermister could keep track of the temperature and shut the amp down if the temp got too high.
I have some experience with peltier devices too, but I don't think that is relevant to audio amplifiers.
another note
Another note about my water cooled system:
The heater core has a 120MM fan on it and dissipates over 100 watts continuously without any problem. The water temperature is about 70 degrees fahrenheit.
The pump isn't very noisy, and I guess if your amplifier is dissipating enough heat to need water cooling, you aren't going to hear it anyway. (unless it's a big class A perhaps
)
Another note about my water cooled system:
The heater core has a 120MM fan on it and dissipates over 100 watts continuously without any problem. The water temperature is about 70 degrees fahrenheit.
The pump isn't very noisy, and I guess if your amplifier is dissipating enough heat to need water cooling, you aren't going to hear it anyway. (unless it's a big class A perhaps
)As promised recently, I'm posting pictures of the water cooling rig I've described in this thread. I'd like to thank my wife for her assistance.
The first one is of the pipe and mounting flange for the output devices. Some people seem to have had trouble visualizing what I was describing when I said that I soldered the flange to the pipe: -O. Perhaps this will help.
The amplifier, for those who might be curious, is a decommissioned Aleph 2 (note the dust). Those are TO-220 output devices; they ran somewhere between 27 and 30W Pd apiece. I've never had an output device failure on the water cooling rig. As long as you can move the heat, it's not a problem.
Grey
The first one is of the pipe and mounting flange for the output devices. Some people seem to have had trouble visualizing what I was describing when I said that I soldered the flange to the pipe: -O. Perhaps this will help.
The amplifier, for those who might be curious, is a decommissioned Aleph 2 (note the dust). Those are TO-220 output devices; they ran somewhere between 27 and 30W Pd apiece. I've never had an output device failure on the water cooling rig. As long as you can move the heat, it's not a problem.
Grey
Attachments
This is an end shot of the heat exchanger I salvaged from a heat pump. There are two independent exchangers, tilted together at the top. The area between them is hollow. The protruding 2x4" scraps hold the heat exchanger up off the floor so as to allow air flow. There is no fan; the air flow is via convection only.
Grey
Grey
Attachments
I spent some time fretting over the amount of surface area between the mounting flange and the pipe, then got over it. Six devices running ca. 30W ea. totals around 180W. That's a lot of heat to extract from one little copper bar, and yet I can put my finger directly on the TO-220 cases and leave it there indefinitely. Given how little the system cost, it's a no-brainer. It'd take an armored car full of money to buy the equivalent passive extruded heat sinks.
I've since acquired two more heat exchangers that I will (eventually) turn into more heat sinks. More particularly, I'm interested in trying a passive/convection system so as to get rid of the water pump. The noise isn't a bother since the pump is in another room...it's the elegance of the idea that attracts me. The Mark II version would also include quick disconnects for the water lines, just to make life easier.
The system I've posted here seems to be damn near bottomless in its ability to wick away heat. I have yet to find a limit, no matter how hard I hit it (several thousand watts-worth of heat and it just smirks and says, "Is that the best you can do?"). And that's with passive air circulation. Should I ever actually get near the limit I can start in on forced air cooling for the heat exchanger.
Some of my ideas haven't worked as well as I'd hoped. This one has far exceeded my expectations. Highly recommended.
Grey
I've since acquired two more heat exchangers that I will (eventually) turn into more heat sinks. More particularly, I'm interested in trying a passive/convection system so as to get rid of the water pump. The noise isn't a bother since the pump is in another room...it's the elegance of the idea that attracts me. The Mark II version would also include quick disconnects for the water lines, just to make life easier.
The system I've posted here seems to be damn near bottomless in its ability to wick away heat. I have yet to find a limit, no matter how hard I hit it (several thousand watts-worth of heat and it just smirks and says, "Is that the best you can do?"). And that's with passive air circulation. Should I ever actually get near the limit I can start in on forced air cooling for the heat exchanger.
Some of my ideas haven't worked as well as I'd hoped. This one has far exceeded my expectations. Highly recommended.
Grey
1984 idea
Was studing for my AS EE in 84 ...happened across the idea of running a micro channel amongs't the multi layers of a VLA chip....running a low surface tension fluid thru it..mount it vertical, have a sharply barbed nozzle at one end, a shrink tube at either end....small" radiator, and use convection for fluid flow.
_________________________________________Rick........
Was studing for my AS EE in 84 ...happened across the idea of running a micro channel amongs't the multi layers of a VLA chip....running a low surface tension fluid thru it..mount it vertical, have a sharply barbed nozzle at one end, a shrink tube at either end....small" radiator, and use convection for fluid flow.
_________________________________________Rick........
Attachments
Grey,
That's a neat, effective system, hats off.
How critical is the solder sweating the pipe to the copper mounting block? Would there be any point in brazing it on, using plumbers brazing rod?
I used a shaded pole purge pump from a dishwasher - it's noisier, and flow is ridiculous, so I put a loop around the pump with a valve to adjust loopback. I ran the pipes through the wall, outside the house, buried them for 10 feet and the soil is the heatexchanger. The pump is mounted under another room, so there is no noise while listening - except the odd gurgle as an air bubble works its way through......
Cheers,
Hugh
That's a neat, effective system, hats off.
How critical is the solder sweating the pipe to the copper mounting block? Would there be any point in brazing it on, using plumbers brazing rod?
I used a shaded pole purge pump from a dishwasher - it's noisier, and flow is ridiculous, so I put a loop around the pump with a valve to adjust loopback. I ran the pipes through the wall, outside the house, buried them for 10 feet and the soil is the heatexchanger. The pump is mounted under another room, so there is no noise while listening - except the odd gurgle as an air bubble works its way through......
Cheers,
Hugh
AKSA said:
Hugh,
As long as the connection is water-tight, you can use anything. Around these parts, solder is the method of choice for connecting copper plumbing. Copper pipe is widely available. The copper bar is 1/4" by 1" if I recall and wasn't all that difficult to find, even here in the hinterlands.
Finishing hints and tips:
--When soldering the 1/4" copper bar to the pipe, I used a standard illegitimate-son-of-an-unwed-mother (gawd, I hate the stupid, puritanical rules about what you can and can't say here) file to support the copper at exactly the right height to fit the center line of the pipe. Bonus to using said file is that the minimal surface contact between the file and the copper means that the heat stays in the copper rather than conducting into the support. Worked like a charm.
--The copper discolors when you solder the joints. If you've got more time in your day than I do, you can patiently burnish the stuff till it glows. I don't have the time. The quick (and cheap, always appreciated) way is to wipe it with a paper towel doused with hydrochloric acid (aka muriatic acid at your local building supplies place--I got mine at Lowe's). Pow! Clean! Done! The fly in the ointment is that it turns the solder black. (Silver content + chlorine > silver chloride and all silver halides are light sensitive, reverting back to particulate silver...etc. etc. etc.) No problem. Since I needed to burnish the thing anyway, it was no extra effort to rub out the visible solder. Actually, if you want to know the truth, I took some tiny jewelers' files and dressed each joint to get the little uneven places tidy. Solder is soft. It takes zero time to file the stuff down.
--Once everything is clean, shoot it with a coat of clear lacquer and it will stay bright and shiny essentially forever. No, I didn't shoot the mounting flange--at least not the top surface--as I wanted good thermal conduction. If you don't handle the copper too much, it will stay clean for quite some time. The surface in the picture has never been touched up and it's nearly as good as the lacquered surface.
--The reservoir takes care of any bubbles in the system, so it's silent. The downstream end of the hose exhausts into the bucket; bubbles rise to the surface and are lost. The other hose is not connected and feeds the intake of the pump. Only water goes in. All things considered, the system burps for about thirty minutes to an hour, then is silent forever after.
raidfibre said:Thanks for reminding me how long I've been active on this forum
Since I last posted on this thread I've transferred schools, graduated college, finished grad school...
Yeah, there've been a few changes here, too.
Grey
Thanks Grey,
Much appreciated. That would be a bustard file, large body, tiny head? I will revisit this soon; as Charles remarked, I have not found a way to reduce the energy consumption of Class A, dammit, but there you go..... onwards and upwards!
Lineup,
The liquid sound of Class A cooled by water, and the hermetic imaging thus derived is a thing of beauty. Nothing like it.... good enough for modern microprocessors, too. Takes me back to my childhood, where 5hp single cylinder gasoline engines in shearing sheds used thermo syphon very effectively indeed, but it took some time to get them up to operating temperature.
Hugh
Much appreciated. That would be a bustard file, large body, tiny head? I will revisit this soon; as Charles remarked, I have not found a way to reduce the energy consumption of Class A, dammit, but there you go..... onwards and upwards!
Lineup,
The liquid sound of Class A cooled by water, and the hermetic imaging thus derived is a thing of beauty. Nothing like it.... good enough for modern microprocessors, too. Takes me back to my childhood, where 5hp single cylinder gasoline engines in shearing sheds used thermo syphon very effectively indeed, but it took some time to get them up to operating temperature.
Hugh
I've seen a guy water cool his CPU by just taking an old gas cylinder and modifying the valve. He burried the cylinder in a big hole out in his garden, then used a pump to get the water flowing through some tubing back into his house and to the computer.
This is my idea of heaven in terms of noise. I can't stand the drone of computer fans or anything like that given the number of hours I can sit at one for. You can even get the pump out in the tank so it makes no noise at all.
Propane tanks, old water cylinders with the insulation stripped, etc
Other ideas...
Maybe pull the radiator off a fridge or car? They're basically free from scrap. Bury one or more of those.
How about having the heat from the system drive a tiny Stirling engine that in turn drives a fan to cool the radiator and your face while you listen?
That would actually be a fun project if you have access to a mill and lathe.
I'm environmentally conscience, just not to the point where I believe that recycling and wind turbines will save us. But energy bills in the UK are absolutely rocketing - 43% up, nasty. In fact, everything is as of late. So I've created the hippy option. Buy an indirectly heated water tank from B&Q (Lowes stateside) and run the hot water from the amp through that.
An indirectly heated tank has a sealed copper coil inside it that you can run the amps hot water through to prewarm the water for a shower.
This is my idea of heaven in terms of noise. I can't stand the drone of computer fans or anything like that given the number of hours I can sit at one for. You can even get the pump out in the tank so it makes no noise at all.
Propane tanks, old water cylinders with the insulation stripped, etc
Other ideas...
Maybe pull the radiator off a fridge or car? They're basically free from scrap. Bury one or more of those.
How about having the heat from the system drive a tiny Stirling engine that in turn drives a fan to cool the radiator and your face while you listen?
That would actually be a fun project if you have access to a mill and lathe.
I'm environmentally conscience, just not to the point where I believe that recycling and wind turbines will save us. But energy bills in the UK are absolutely rocketing - 43% up, nasty. In fact, everything is as of late. So I've created the hippy option. Buy an indirectly heated water tank from B&Q (Lowes stateside) and run the hot water from the amp through that.
An indirectly heated tank has a sealed copper coil inside it that you can run the amps hot water through to prewarm the water for a shower.
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