Custom water-cooling

[kladner]

With peltiers it is good to remember that you have to supply somewhat more power than the amount of power/heat you wish to dissipate. Then you have to get rid of more than twice as much power/heat as you started with.

What's wrong with good old compressor-driven refrigeration? It seems that you could park a condensing unit outside, and set up a dandy chilled water system inside. It would be interesting to compare the power budgets of multiple peltiers and a compressor.

[LaurV]

Well, with the aircond, same as with peltiers, the biggest problem is still the condensation, (and not "removing the additional heat", which, in fact, is produced far away, where your compressor is, or where your peltier power supply is, and _not_ inside of the case). The air dissolves a qty of water direct proportional with its temperature (that is why the hand driers work), so inside of your computer case, the hot air contains more water than the cold air lagging around your pipes. Which results in water droplets all around the (path, pipes, hoses) where the cold (air, water, liquid, freon, whatever) stuff go. Those water droplets have a bad habit of following the gravitation paths into your mobo or vga cards, getting the magic smoke out...

[Chuck]

Originally Posted by LaurV

and the rack outside, sorry for the quality of the photo, is from the window, no way I could go out there now, you know snakes, scorpions, ghosts, etc...

When I used to participate on the SETI computing project, there was a fellow who had a setup similar to yours except he had an aquarium cooler in the loop (sort of a small refrigerator-pump device).

[VBCurtis]

Originally Posted by LaurV

Well, with the aircond, same as with peltiers, the biggest problem is still the condensation, (and not "removing the additional heat", which, in fact, is produced far away, where your compressor is, or where your peltier power supply is, and _not_ inside of the case). The air dissolves a qty of water direct proportional with its temperature (that is why the hand driers work), so inside of your computer case, the hot air contains more water than the cold air lagging around your pipes. Which results in water droplets all around the (path, pipes, hoses) where the cold (air, water, liquid, freon, whatever) stuff go. Those water droplets have a bad habit of following the gravitation paths into your mobo or vga cards, getting the magic smoke out...

This is not-quite-true for Peltiers. The hot side of a peltier dissipates all of the heat from the chip plus all of the heat from the power drawn. Usually, the peltier is placed between the chip and the water block, so that heat is inside the case. I suppose you could try peltier-cooling your water, but I doubt that would be very effective.

[Mark Rose]

Originally Posted by LaurV

Ye dreaming, hehe, "cooler months" here mean +12C in the morning, since 15 years the lowest I ever saw in my area was a very cold end of November few years ago when it dropped to +9C, and usually the "winter" here corresponds to the "dry season" (no rain from about end of October to May, with very few exceptions, there are few rainy days in March, called the "mango rain", because if it rains at that time the mango fruit gets bigger and sweeter). I never seen "condensation" in this period, even the dew is extremely scarce and the grass under the threes dies (the other is still receiving some dew in the morning and survives) if ye don't water it. Sometime I really envy your guys living in colder countries, and I am missing the snow, and think nostalgically to Romanian winters, with -20C and one meter of snow... What a data center I would do there... (assuming I can lock the same income, of course, hehe). I would not have the cooling problems I have here... fighting the heat 10 months per year... But on the other side, no money spent on coats, boots, preserves, etc, I have fresh fruits all the year and I can go to job with the same shorts and t-shirt 200 days a year...

A minimum 12°C temperature is a warm month to me. I'm most comfortable in temperatures below 20. I might visit Thailand some day, but you'd have to pay me a huge amount to live there :)

The western mountains of Romania wouldn't be so bad though!

[kladner]

Originally Posted by VBCurtis

This is not-quite-true for Peltiers. The hot side of a peltier dissipates all of the heat from the chip plus all of the heat from the power drawn. Usually, the peltier is placed between the chip and the water block, so that heat is inside the case. I suppose you could try peltier-cooling your water, but I doubt that would be very effective.

That is what I thought. The heat at the power supply is another issue.

[TheMawn]

The small form factor of Peltiers makes it stackable, too. If you stack one on the other, the cold side of the first is in contact with the hot side of the second, making the cold side of the second extra cold. It takes more energy to do this, though, making the hot side of the first one extra hot. You can make a pyramid with these things to increase the surface area as you stack more and more so that the hottest side has a larger surface area to cool.

You would want to do this with a very robust liquid system (although phase change would open the door for very, very cold temperatures).

[kladner]

Why do peltier if you have phase change?

[chalsall]

Originally Posted by TheMawn

You would want to do this with a very robust liquid system...

And, perhaps, a vacuum chamber...

LaurV did talk about condensation... Can be a pain when there's H₂0 in the air....

[chalsall]

Originally Posted by kladner

Why do peltier if you have phase change?

Pumps vs. media.

[kladner]

Originally Posted by chalsall

Pumps vs. media.

Eh? My question was, basically, if you can have water at 1 C circulating, why add the complications involved with peltier junctions? I suppose if you want to get to another level of chilling, cooling the peltiers with that water could be an option.