Well this is interesting

Posted Mar 3, 2026 22:06 UTC (Tue) by epa (subscriber, #39769)
In reply to: Well this is interesting by Cyberax
Parent article: Gram 1.0 released

I guess if it's winter and you need to heat your home anyway, the energy is not totally wasted.

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Well this is interesting

Posted Mar 3, 2026 22:45 UTC (Tue) by Cyberax (✭ supporter ✭, #52523) [Link] (3 responses)

Sure. But then why aren't you using a heat pump for heating?

I guess the only really advantageous use of CPU-based heating is for hot water heating. I know that there were bitcoin mining rigs integrated with water heaters, but it might be tricky to do for regular computers. Typical ~50C water temperatures don't provide a lot of thermal headroom.

I was idly thinking about using my computer to pre-heat water in an intermediary tank, a 200W computer will heat 1 liter of water by 1 C every 20 seconds. This is more than enough to cover my daily usage, so a larger heater will just need to boost the temperature from whatever the intermediary tanks ends up at to the nominal 55C.

Well this is interesting

Posted Mar 4, 2026 0:30 UTC (Wed) by himi (subscriber, #340) [Link]

Heat output of a single PC is going to be too variable to be useful for anything other than basic space heating - your outlet temperatures won't get high enough to be useful unless it's running flat out for an extended period of time, the average temperatures will be so low that they'd only be marginally useful even for heating. Not to mention the challenges of managing the /inlet/ temperatures when you're trying to extract useful heat energy across a fairly wide range of temperatures.

This is another situation where you need to do things in bulk for it to be useful - the heat energy byproduct of a datacentre is going to be far more consistent, and therefore much easier to work with even if the actual outlet temperatures aren't really high.

Well this is interesting

Posted Mar 6, 2026 15:22 UTC (Fri) by smoogen (subscriber, #97) [Link] (1 responses)

Some of the 'this is what your datacentre will need to supply if you want to use our XYZ server' have been "you could heat a Roman bath house". One set was talking about gallons of water per minute per block(*) with an intake temperature of 4C and outtake temperature of 40+C. [* It wasn't clear in the short read I had was if this was per rack of servers or per server.. I am hoping it was per rack.] This seems to be one of those 'oh we don't look at those costs' which get hidden in AI uses X amount of electricity. There is a large amount of water needed to basically turn to outside steam at chiller plants plus other cooling technologies. Now instead of just pumping that water to the sky directly.. why not put a large neighborhood bath and steam house for the people who have to hear the fans 24x7

Well this is interesting

Posted Mar 7, 2026 0:42 UTC (Sat) by malmedal (subscriber, #56172) [Link]

> why not put a large neighborhood bath and steam house

Heating e.g. swimming pools has in fact been done, but the cooling effect of vaporising water is equivalent to heating the water by 540 deg C, so most datacenters want to exploit that.