Reflections on watercooling: Difference between revisions
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* We don't use Fahrenheit, but it's worth knowing that each ℃ is 1.8℉, with an offset of 32. We don't really use Kelvins either, but Kelvins are equivalent to Celsius with an offset of -273.15. Rankines can fuck right off. Liquids boil at lower temperatures at higher altitudes (boiling occurs when internal vapor pressure equals atmospheric pressure). Water expands both above and below 4℃. A quick table: | * We don't use Fahrenheit, but it's worth knowing that each ℃ is 1.8℉, with an offset of 32. We don't really use Kelvins either, but Kelvins are equivalent to Celsius with an offset of -273.15. Rankines can fuck right off. Liquids boil at lower temperatures at higher altitudes (boiling occurs when internal vapor pressure equals atmospheric pressure). Water expands both above and below 4℃. A quick table: | ||
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* Neither air- nor water-based cooling can get your temperatures below ambient (this can be achieved with phase cooling, thermoelectric aka Peltier, and cyrogenics). If it's 30 degrees in your room, your coolant and component temps are going to be at least 30 degrees. <b>It is useless to report temperatures without reporting ambient temps.</b> The effectiveness of your cooling system is measured by how close it gets to ambient, ΔT. Likewise, your heat-generating components are going to be hotter than your coolant. | * Neither air- nor water-based cooling can get your temperatures below ambient (this can be achieved with phase cooling, thermoelectric aka Peltier, and cyrogenics). If it's 30 degrees in your room, your coolant and component temps are going to be at least 30 degrees. <b>It is useless to report temperatures without reporting ambient temps.</b> The effectiveness of your cooling system is measured by how close it gets to ambient, ΔT. Likewise, your heat-generating components are going to be hotter than your coolant. | ||
* <b>The goal is to move heat from the heat-generating components, and ultimately from the case.</b> If you can't remove as much heat as you generate, temperatures will rise with time. If you can remove all the heat you generate, temperatures will fall towards ambient. Effectively moving heat requires (a) thermal conductivity, (b) contact area and (c) a temperature gradient. The thermal conductivity of air is about two orders of magnitude less than water, which is about two orders of magnitude less than aluminum or copper. | * <b>The goal is to move heat from the heat-generating components, and ultimately from the case.</b> If you can't remove as much heat as you generate, temperatures will rise with time. If you can remove all the heat you generate, temperatures will fall towards ambient. Effectively moving heat requires (a) thermal conductivity, (b) contact area and (c) a temperature gradient. The thermal conductivity of air is about two orders of magnitude less than water, which is about two orders of magnitude less than aluminum or copper. | ||