Water Cooling

[BrianDonegan]

Ah, good question. Distilled water would not. Water by itself is not conductive, but the minerals in the water are. Water is bipolar, however, so I was curious as to the effect, if any, it might have flowing past a current source.

I think after the copper oxides form on the inside of the pipes, it would stop any damage from the distilled water.

[GRollins]

I don't think I've seen a post yet that isn't a carbon copy of a post in an earlier water cooling thread. All the same ideas and criticisms keep coming up, over and over again.
Those who wish to guild the lily would do well to build a basic system first. I think you'll be astounded to find how well it works. All these embellishments are unnecessary in the purely functional sense. If you want to use oils and greases and gold-plated stuff, that's cool. Just be aware that you'll be spending money that you don't need to spend.
Not to belabor the obvious, but those who are worried about chemical reactions and copper pipes are ignoring the simple fact that houses have had copper pipes for years...decades, in fact...with all sorts of local water conditions, from soft to hard, and all points in between, and yet the pipes somehow seem to function just fine.
Sigh...
At the risk of repeating myself, it works. You don't need to lay awake nights staring at the ceiling, fretting over this and that. It's just not that complicated.

Grey

[BrianDonegan]

I agree, fully. Want it to be fun, effective, and (hopefully) good looking. I plan on using your idea for the plate and pipe, was just trying to come up with a neat way to not use mica. May still, just floating ideas.

I am not at all concerned about the copper pipe breaking down, though old pipes are full of all sorts of crud (greenish blue from the copper). I just want this thing to last, thus my concern for any non-copper parts.

The only thing remaining to be decided is what pump to use. Doesn't need to move much water, just has to be silent.

[GRollins]

I used mica insulators (TO-220 devices). Doesn't bother me a bit.
Keep in mind that since this is a closed system--at least mine is--that whatever chemical reactions may occur are going to reach their endpoint pretty quickly, after which there will be very little if any change.
Put the pump in the other room with the heat exchanger. Worked for me.

Grey

[Variac]

It's true - nothing new yet, but it is so fun to brainstorm I can't blame you guys. I know distilled water isn't conductive, BUT I feel that distilled water WILL become conductive once it has collected some impuities. This is an example of what Grey is saying - in this case fancy stuff like distilled water might be worse than just some tap water. After all, how much calcium build up are you gonna get from a closed system?

[jacco vermeulen]

Originally posted by WorkingAtHome
Then I remembered PEX

We have that overhere too, DIY centers sell the stuff by the roll.
Here it is called Thylene hose.
(unlike the US, people do a lot of home diy-ing in europe)
Newbuilds do not have copper piping anymore for 10 or so, polythylene hose is embedded in concrete, with brass connectors.

When i read your posting, Brian, i crosslinked the PEX to floorheating hose. That is the most common floorheating system here, hot water running through plastic hose embedded in the floor.
Suppose i have a copper or alloy block with floorheating hose going through it, inside an amplifier.
If the copper is electrically isolated from the chassis, the output devices could be mounted without insulators, for PP amps that would require two cooler blocks.
I already built a set of amplifiers once with the heatsinks inside the chassis, TO220 RFP mosfets mounted naked on the heatsinks. Those amps were even commercially built like that.

Such a block could be covered with floor coating to make it fully isolated(epoxy coating).
In my high school days i worked as a quality control guy in a glass factory, i remember how durable the epoxy coated plant floor was.
Floor heating has a 60F dT, i think. About the same as amplifier heatsinks. I am going to check on the web what the heat transfer factor for that kind of hose is.
Water hose inside an amplifier could be fitted as double barrier, in case of a leakage the second barrier hose removes leaking fluid to the exterior of the amp.

[SM2GXN]

Distilled water can aggressively steal ions from piping. better to use water filtered with a drinking water filter- not an osmosis system. Working:
Wouldn't the water in the plastic pipe short the output devices ?

Hi Variac!

Since the voltage in most cases are below 200 volts I don't think you have to worry about shorting the output devices .
I prefer distilled water for high voltage but I have even tried to use ordinary tap water as coolant at voltages above 1kV, the result was more current running in the water to ground beacuse of better conductivity . To measure this I used an uA-meter soldered to a small piece of copper tubing which was placed somewere between the radiator and the amplifier. After some 5-6 months the current slowly rised to 10-20uA then it was time to replace with fresh distilled water. The conductivity will rise as the water get poluted. Excuse me for reffering to a tube amplifier but think this will apply to a transistor amp as well.
For tubes you can exceed the dissipation with about 2-2,5 times with water cooling, compared to air colling the power output would be doubled.

Most recreational suppliers will probably stock lots of good stuff for this.

Bjorn

[BrianDonegan]

So, I have decided that (for me) trying to acheive isolation for each transistor would be too bulky, withtoo many connections. Not very elegent anymore, and more prone to leaks. Mica it is (or thin sil pads, kapton tape, etc).

Jacco-
People in the US do lots of DIY-home stuff as well. Home Depot as helped create a massive market for it. PEX has been used in heating for several years now, and is slowly being approved for water supply lines, state by state. Massachusetts just approved it in the last few years. There have been some bad experienced with non-cross-linked poly-eth pipe in the past breaking down, etc.

Putting the pump and heatexchanger in a different room isn;t really a good option for me. I was thinking about a second chassis that holds both.

Again, just brainstorming, I was thinking about using a plate and pipe setup as in the amp, but mounting these on the plates:


( - Dimensions : 136(L) x 136(W) x 67(H)mm
- Weight : 918g
- Base Material : Pure Copper
- Dissipation Area : 3,268 cm2
- Bearing Type : 2-Ball
- Speed : 1,000 ~ 2,000rpm ¡¾ 10%
- Thermal
Resistance : 0.19 ~ 0.24¡ÆC/W
- Noise Level : 20 ~ 32dB ¡¾ 10% )

Maybe 4 or 6 total mounted on two or three horizontal copper plates. Still thinking. I will more likely use the baseboard idea, but this would be really cool looking.

[jacco vermeulen]

That Zalman looks Cool !

Sorry Brian.
Maybe Texas is the only state where people are less Home
DIY-ers, not like the total renovation jobs you see here.
In France it is common to build complete homes.
France has a DIY center on every corner, and they sell the most marvellous goodies.
My experience anyway, could be that i only know Yuppies.

[BrianDonegan]

I might send them an email to see if they can supply these without a fan. Would be a nice replacement for the typical aluminum fin heatsink...