Pro/Forums - View Single Post - Peltier-based water-chilling experiment

Cathar · 02-17-2003, 06:55 AM

Hi All,

This is the first stage of a longer term project I've got going. I picked up 2 x 172W 40x40mm peltiers today and setup a peltier-based water-chiller using my first Hydra prototype block (no - not the production prototype - just the first concept prototype I had made some months back).

Basically I've just conducted a non-heat-loaded experiment where I have an Eheim 1048 pump in a bucket, which pumps water to the Hydra block on the cold side of the pelt, and then back into the bucket again. The hot side ofthe peltier is cooled with a spare water-block I had kicking about which I just plugged into my main computer water-cooling loop so it would be cooled by the computer's main radiator.

The peltier was driven off the 12V rail from the PSU. Now this isn't exactly best for the peltier as it's rated for 24V. This is half-voltage, so as I raise the voltage I'm hoping that there's a good deal more cooling power to be had from the peltier (figure I'm at 80W now - hoping for 120W max).

Okay, so I got the system fired up with 4l of water in the bucket. The rate at which the water temperature was dropping is indicating that the peltier is removing heat at the rate of about 80W from the water. Not bad for a prototype block on the cold-side and for the hot side of the peltier not really being cooled that well, and the peltier at half power.

I got the water to ice solid in about 90 minutes, which if you think is crappy, then ask yourself how long does it take your freezer to get a room-temperature 2l bottle of coke to turn to ice?

I know you want to see them, so here's some piccies.

The Setup:

...and after the icing of the reservoir:

The water remains fluid until about -2.2C until the water ices up in the block. This causes the pump to stop, and then the currents stop in the reservoir, and over about 3-5 seconds the whole reservoir turns to ice and the temperature jumps up to -0.1C when the phase-change takes place. Very interesting to watch it happen.

This is just stage one of the experiment.

The end goal here is to power the peltiers properly (~18V) and hook them up in series with 4 blocks to provide around 3x the cooling power of this single peltier test. All up I'm aiming for 220-240W of cooling power to apply to the CPU and GPU water-blocks (which in total push out about 100W - being real watts - not "radiate" watts). Given that the 80W of cooling power of this test was able to bring the coolant down to -2.2C before it froze over, I'm hoping that with an alcohol/water mix and the surplus 120W of cooling power (220-100) of the final setup will allow me to achieve -10C (or maybe lower) coolant temperatures once I get the proper Hydra blocks onto the job.

02-17-2003, 06:55 AM	#1
Cathar Thermophile Join Date: Sep 2002 Location: Melbourne, Australia Posts: 2,538	Peltier-based water-chilling experiment Hi All, This is the first stage of a longer term project I've got going. I picked up 2 x 172W 40x40mm peltiers today and setup a peltier-based water-chiller using my first Hydra prototype block (no - not the production prototype - just the first concept prototype I had made some months back). Basically I've just conducted a non-heat-loaded experiment where I have an Eheim 1048 pump in a bucket, which pumps water to the Hydra block on the cold side of the pelt, and then back into the bucket again. The hot side ofthe peltier is cooled with a spare water-block I had kicking about which I just plugged into my main computer water-cooling loop so it would be cooled by the computer's main radiator. The peltier was driven off the 12V rail from the PSU. Now this isn't exactly best for the peltier as it's rated for 24V. This is half-voltage, so as I raise the voltage I'm hoping that there's a good deal more cooling power to be had from the peltier (figure I'm at 80W now - hoping for 120W max). Okay, so I got the system fired up with 4l of water in the bucket. The rate at which the water temperature was dropping is indicating that the peltier is removing heat at the rate of about 80W from the water. Not bad for a prototype block on the cold-side and for the hot side of the peltier not really being cooled that well, and the peltier at half power. I got the water to ice solid in about 90 minutes, which if you think is crappy, then ask yourself how long does it take your freezer to get a room-temperature 2l bottle of coke to turn to ice? I know you want to see them, so here's some piccies. The Setup: ...and after the icing of the reservoir: The water remains fluid until about -2.2C until the water ices up in the block. This causes the pump to stop, and then the currents stop in the reservoir, and over about 3-5 seconds the whole reservoir turns to ice and the temperature jumps up to -0.1C when the phase-change takes place. Very interesting to watch it happen. This is just stage one of the experiment. The end goal here is to power the peltiers properly (~18V) and hook them up in series with 4 blocks to provide around 3x the cooling power of this single peltier test. All up I'm aiming for 220-240W of cooling power to apply to the CPU and GPU water-blocks (which in total push out about 100W - being real watts - not "radiate" watts). Given that the 80W of cooling power of this test was able to bring the coolant down to -2.2C before it froze over, I'm hoping that with an alcohol/water mix and the surplus 120W of cooling power (220-100) of the final setup will allow me to achieve -10C (or maybe lower) coolant temperatures once I get the proper Hydra blocks onto the job. Last edited by Cathar; 02-17-2003 at 03:41 PM.