It's actually very inefficient use of energy to use miners as electric heaters.

Now that we care about energy efficiency and atmospheric pollution, hopefully more people will learn that efficient electric heating takes the form of a heat pump, where you end up with more heat energy in your space than just the electricity put into the device.

A miner cannot match the heating efficiency of a heat pump because it dissipates the negative-entropy into computation instead of pumping.

Kind of true, but is it widely used form of producing heat? From where I live, the heater burn gas from PG&E. So it is still doing the inefficient kind of turning energy into pure heat.

I’m still undecided on the subject (whether crypto-currency is intrinsically bad to the environment or not.) Eg what if we regulate and only allows renewable energy to perform this. The basic argument is to intercept energy which would have been turned into heat anyway (solar, geothermal, etc.) and instead directly turned into heat, perform mining first then to heat.

For others who may misunderstand, they are talking about thermodynamics. Ie the amount of heat produced can be higher than the energy you put it, because it also get some from the environment. A random article found on the subject: https://courses.lumenlearning.com/physics/chapter/15-5-appli...

Indeed. The only use case for resistive heaters is when air-sourced heat pumps are much less efficient - in the extreme cold (significantly below freezing).

In any case, the miner fans are loud.

Or when you don't have central heating/air.

Or when you can't afford a retrofit of your system with a heat pump.

Or when you need to target dry a small room or a pair of wet shoes.

They have plenty of other uses, the only caveat I guess is that they aren't used as the main source of heat.

> In any case, the miner fans are loud.

That's why I proposed encasing them in a heat transfer shell and keep the thing submerged in water. They could keep the water in the boiler at around 60 Celsius.

At what temperature would a heat pump be less efficient than an electric resistance?

A proper heat pump is never less efficient than an electric resistance.

Soil, at a depth of only around a few meters, rarely exceeds 10C, even in summer. That gives you a 45C differential for your boiler in the worst of worst cases with a ground heat exchanger, which is more than enough for best-case efficiency, year long.

This will be less expensive than a crypto in material cost very rapidly.

> This will be less expensive than a crypto in material cost very rapidly.

That I never doubted.

> At what temperature would a heat pump be less efficient than an electric resistance?

There is no such temperature, with a good enough design of heat pump. A good heat pump is always more efficient at heating than electrical resistance.

The improvment is a multiplication factor, which can be quite large; it's not just a few percent. The factor is why I'd describe mining - or resistive heating - as a very inefficient use of electricity for heating.

Since we are theorising about the merits of miners, we may as well use the theoretical limit for the alternative. Wikipedia explains: "If the low-temperature reservoir is at a temperature of 270 K (−3 °C) and the interior of the building is at 280 K (7 °C) [...] only 1 joule of work [...] 28 joules of heat are added to the building interior".

In other words, a heat pump can be 28 times more efficient than running a miner or other resistive electrical heater in those conditions. But that's a high number, a theoretical limit in conditions chosen to put heat pumps in their best light.

More realistic, based on real devices: "In Europe, the standard test conditions for ground source heat pump units use 35 °C (95 °F) [...] and 0 °C (32 °F) [...] the maximum theoretical COPs would be [...] 8.8. Test results of the best systems are around 4.5. When measuring installed units over a whole season and accounting for the energy needed to pump water through the piping systems, seasonal COP's for heating are around 3.5 or less. This indicates room for further improvement."

So 3.5-4.5 times more efficient than running a miner for heating in real conditions with current heat pumps, which can be improved. That translates directly to reduced atmospheric emissions from electricity generation.

The efficiency of the heat pump reduces when the outside temperature reduces, and reduces when the inside temperature increases. Conversely, if you are heating water, the time when the heat pump is most efficient is in the summer.

Cost is distinct from efficiency. The cost of a unit of energy as electricity is higher than the same unit of energy as gas, for example, so if you are comparing an electrical heat pump to gas heating, at a low enough outdoor temperature the gas heating is cheaper. This is why some places switch between heat pump and gas modes. The same argument does not apply when comparing with electrical heating like miners, or with an electrical water boiler.

> reduced atmospheric emissions from electricity generation

That's a key point. If your power comes from renewables, this discussion is a lot less interesting. I'm all in for efficient use of energy (and I don't think crypto mining is a good use of it), but I also know a heat pump is a lot more complicated than an electric resistance (or a hot PCB board).

> It's actually very inefficient use of energy to use miners as electric heaters.

Not sure I get where are you going here. There is no mechanical output of the miners, only heat.

> A miner cannot match the heating efficiency of a heat pump

My hot water comes from the heat pump in the winter, when heating kicks in, but the boiler relies on an electric resistance in summer, when the house is mostly in equilibrium with the outside.

> the boiler relies on an electric resistance in summer, when the house is mostly in equilibrium with the outside.

That's the situation where a heat pump is most efficient. I think you could reduce your hot water electricity cost by a factor of 3 by using heat-pumped hot water in the summer, instead of resistive heating. I guess the reason your system doesn't do that in summer is that it would require separate equipment.

With the assumption of outdoor temperature 30°C and water 60°C, the theoretical limit is a factor of about 10.

With so many people experiencing a cost-of-energy crisis at the moment in the UK, it's disappointing that these methods are rarely seen here. I've never seen a heat pump in a home in the UK.

If you were to invest the amount of money that a good crypto setup would cost, a heat-pump with an underground loop would be miles more efficient in the summer than an electric resistance.

This is the only justification for mining I’ve ever been able to come up with.

It's not even correct. It's much more efficient to use a heat pump.

Heat pumps may be more efficient, but they can't be employed everywhere an electric resistance is used. To be fair, miners can't either, but are much easier to deploy.

We don't need to think solely of miners - crypto-mining is just one form of monetizing computing. If we could have something like a reverse Amazon Mechanical Turk, we could put computing resources available to receive and process packaged workloads cheaper than, say, an EC2 Spot Instance could, provided the client can cope with the added latency. As for incorrect answers, it could use some consensus where you send the payload to two independent parties and, if they don't match, you send it to additional parties until your consensus is ready.

There are no applications I can think of where crypto-heating works, but a heat pump doesn't. Miners are a lot more difficult to deploy than a heat pump - they need an internet connection, they can break down, they will eventually need to be upgraded, etc..., whereas a heat pump is pretty much once-and-done, and you'll maintain it once every few years.

As for your second paragraph, will it ever be cheaper to do a computation twice independently than once in a trusted party? I'm sure there are a few situations where that's the case, but I struggle to think of them.

Here are two scenarios when a heat pump is harder to deploy: 1) Heat pumps need access to the outside cold reservoir, for example they don't work entirely inside a closed room, where an space electric heater would be fine. 2) If the temperature gradient is too large, heat pumps are less efficient than a regular heater. So many heat pumps fall back to a regular heater when the outside gets too cold. If it is very cold all the time, a heat pump would not make any sense at all. This is why they are deployed mostly in places with mild winters.

This is flat out wrong. Heat pumps are only practically efficient within a range of temperature differentials.

You already need the heat, might as well help launder some money ;-)

More or less. I guess there’s incentive issues too. Maybe now people keep their houses unnecessarily warm to mine more —- but again, this is the closest thing to any kind of justification I’ve ever heard.

Now all we need is a way to make that boiler lined up with top-process silicon costing thousands of dollars per square inch cheaper than the one that uses an electric resistance.

And do that for the environment!

With all the discussion around UBI, housing shortages, and crypto, I think it would be interesting to build tiny houses with solar arrays that would be funded and heated by the crypto miners running in them.

They don't need to be tiny (unless we want to maximize external surface and, with that, the heating requirements).