HACKER Q&A
📣 sschueller

Bitcoin miner vs. my hot water heater


Serious question regarding energy usage.

Is there a large difference between the energy used by my hot water heater which is basically a wire with resistance that gets hot vs a crypto miner that gets hot?

How does flipping bits in a CPU compare with the resistance in a wire?

I'm not going to replace my hot water heater with a miner but I am curios about how they compare. People are complaining a lot about the wasted energy in mining and I am wondering if it would make sense or be feasible to use the heat energy generated by mining like in certain data centers. [1]

[1] https://en.wikipedia.org/wiki/District_heating


  👤 TrickyRick Accepted Answer ✓
100% of the energy you put in to a computer gets converted to heat. So if you have a GPU that draws 250W, that's 250W of heat you're putting into the atmosphere. It's not that much compared to a heater which I would presume is on the order of a few 1000W and also directs the heat straight into the water it's heating.

👤 h2odragon
Bitcoin miners are going to be slightly less efficient heaters than heaters, usually, because they "waste" some electricity making light, too.

Your water heater is more efficient at heating the water because its in direct contact with it, and those heat elements get hotter than any part of computers usually should.

Otherwise, watts are pretty much watts and heat acts the same whatever generated it.

I built my house in 2005 intending to use the 500 sq ft data center portion of it to heat the rest. Of course, those plans changed and now the house has a natural cold room and nasty heating bills in winter; but we barely spend anything for AC in summer.


👤 yagizdegirmenci
Something like this was previously discussed earlier this year: How I heat my home by mining crypto currencies and cutting my electricity bill in half in the process [1]

[1]: https://news.ycombinator.com/item?id=26235414


👤 twobitshifter
Yes you could it and it would be a better use of money than an electric water heater. From my understanding of crypto mining, the energy usage on off the shelf machines is usually greater than the immediate value of the coins mined. Using it to heat water could change the economics. As the value of coins is always changing these coins could be held as an investment or coins could become valuable enough that they are profitable from the time of mining.

I remember a startup selling cpu based heaters to support cloud services, there could be a similar market for water heaters. If you have a cpu in your house you’re already heating with it whether you know it or not.


👤 imhoguy
Manufacturing, safety, maintenance and recycling cost definitely matters. Other than that from physics point of view you just immerse it and hundreds of Watts radiate into liqid as heat, and with miners a few Watts return as electricity with the information over wires.

You may need no sealing if dielectric thermoconductive liquid is used, but such is synthetic toxic mix usualy.

Don't forget abot heat from power supply unit.