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Why thermo-electric cooling instead of more efficient forced-air cooling?
by mrob 8y ago
Why thermo-electric cooling instead of more efficient forced-air cooling?
- bcaa7f3a8bbc 8y agoor passive cooling with huge heatsink.
- ChuckMcM 8y agoAs it turns out, forced air cooling isn't as efficient as water is for carrying heat. As a result the most efficient way to cool a server is to put a water filled heat exchanger in front of it and let the computer's fans draw air through that into the chassis. And that leaves you with how to dump the heat out of the water, and that is most effectively done (in a small scale) with thermo-electric coolers. You can add scale cooling very effectively by turning on additional coolers. My design is pretty simple, the reservoir tank is on top of the rack and there is a heat exchanger on the bottom and one in "front" of the CPUs. As they draw air through the heat exchangers the water warms and rises to the top where the reservoir is, and the chilling water in the reservoir naturally sinks back down to the bottom where the first heat exchanger is. You can think of it like a rack sized version of the liquid cooler you can put on an enthusiast PC these days. Its quiet, self contained, and quite efficient, while still being able to use forced air cooled server equipment. The goal being efficient cooling in a temperate climate (California Bay Area) that is quiet and can use surplus/old equipment that was originally slated for a data center without violating any of that equipment's assumptions about the environment it can count on.
- mrob 8y ago>that leaves you with how to dump the heat out of the water, and that is most effectively done (in a small scale) with thermo-electric coolers This is the part that sounds strange to me. Water cooling has its advantages, but the heat is almost always dumped from the water by pumping it through a radiator that has fans blowing air through it. What's the advantage of thermo-electric cooling here over the traditional method?
- ChuckMcM 8y ago> What's the advantage of thermo-electric cooling here over the traditional method? 1) It is quiet 2) It is easily electronically controllable based on the heat load in the water. The heat sinks on the thermo-electrics are convection cooled and you could blow air over them but as you increase the thermal gradient between the heat sink and the air around them you are able to dump more heat. The only parameter you can vary with the typical heat exchange is "blow more air" you can't change the working temperature of the exchanger. That said, the way power plants cool their water is in big evaporative cooling towers, but since I don't need a humidifier for the lab I stick with just convection cooling :-)
- newnewpdro 8y agoAre you talking about using Peltier devices when referring to "thermo-electrics" here?
- ChuckMcM 8y agoYes. I bought a bag of 12V ones at a local surplus shop.
- neuralRiot 8y agoI had something similar to this on my old P4x rig had watercooling with the radiators mounted horizontally outside the case, made a thermal controller for the fans and most of the time they where stopped or at maybe 40% speed, only with heavy loads they went faster. Now i have an arcooled I7 and the fans drive me nuts.
- benwills 8y agoI've spent a fair amount of time this year with liquid cooling designs, and final parts are coming in to do something along the lines of what you're talking about. Do you have any blog posts/videos walking through this? It sounds really interesting and I'd love to see it.
- fake-name 8y ago> As a result the most efficient way to cool a server is to put a water filled heat exchanger in front of it and let the computer's fans draw air through that into the chassis. What standard are you using for "efficient"? Thermo-electric coolers are neat, but the last thing they are whatsoever is efficient from a power-usage stand point. If you're doing chilled water cooling, the only real option to consider is a mechanical heat pump (e.g. the ones in a refrigerator), but even that is silly. Hardware doesn't mind being somewhat warm, and using ambient air for cooling is far more efficient then either. There's a reason thermoelectric refrigerators aren't really a thing. Peltiers are horrible. Mechanical heat pumps easily achieve twice the efficiency or more.