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Comment by legutierr | Hacker News Reader

> there are enough anecdotes of people in Siberia heating their kitchens with GPUs

Hey, all you blockchain skeptics, here’s what you are always asking about: a practical use for blockchain tech.

Resistive heating will generally be less efficient than heat pumps, although potentially Siberia is cold enough to mitigate that?

I couldn't actually find anything about this in a search, but I think the point is that they're already using the GPUs for something else, and heating their kitchen with the excess heat just makes sense at that point.

The only thing I did find was that apparently Russians are taking the components from kitchen appliances to use for other things, which seems entirely unrelated.

This isn't really a "practical use for blockchain tech". Rather it's just a positive way to use the side-effect that blockchain tech requires computing components that generate a lot of heat.

Ultimately the heat output has nothing to do with how the tech is used (like bitcoin). If Bitcoin (or other cryptocurrencies) stopped holding value people wouldn't heat their homes like this because it would cost more than traditional heating methods (as someone pointed out above about heat pumps.)

I've been doing a lot of ML training, particularly when my office is cold. Kills two birds with one stone.

But with bitcoin mining your heat pays for itself, while if you use a heat pump you have to buy power to run the heat pump. So while heat pumps are more energy effient, bitcoin miners are far more economically efficient.

This is only true if the value of the Bitcoin you mine is higher than the difference in cost between buying and operating a heat pump and buying and operating a mining rig.

Heat pumps are not cheap, $10-$15k installed for a small one.

the one in my cabin cost me $800 including installation.

Neither are GPUs that are run 24/7 at full speed

A split AC unit that can also run backwards is less than 1000 and basically a heat pump. Not all split units that heat will do that, but a bunch do.

Are you talking about something that fits in a window and warms a single room?

I recently replaced the 3 ton hvac unit on my small 1500 sq ft single family home with a heat pump and all the bids were in that range.

Yeah single room. There's dual room splits that run a bigger compressor with two heads too. They are usually way cheaper than bigger units even when you account how much juice they eat up but you should do your own math because it depends on the house and the setup.

Also if you want to control every single room including bathrooms and walk in closets it gets tricky.

2/3rds of that cost is labor. 3 ton multi-zone heatpump kit is $2500-3500, another $250-500 for an electrician to pull #6s and a ground to a 60A disconnect outside and sealtite whip into the heatpump, and 60-80 hrs at $125/hr to install the heat pump and air handlers, including all the exterior wall penetrations and sealing, running glycol lines, installing thermostats, wiring air handlers, etc.

I don't agree with a lot of things in CAPEX vs OPEX, but this is one that is clearly right:

Having equipment sitting around unused is way more expensive than most people care to think about.

A heating coil might not be terribly valuable in July, but come November it will have roughly the same value it had the previous February. Bitcoin mining hardware that's switched off for five months is losing value at an alarming rate, and very quickly won't be a net reduction in costs.

Very quickly a heat pump becomes cheaper to operate, and cheaper to purchase. And if you amortize the cost over the life expectancy, that threshold is very, very low. People who have recent memory of living paycheck to paycheck are constantly screwed by the latter, and that Venn diagram overlaps heavily with several other circles that make crypto super attractive to some people and super ridiculous to others.

I went down this avenue of compute as radiator long ago, and I could never get the math to work, unless I moved somewhere that was cold most of the year, and that sure as fuck is not going to happen.

Curious, what things in “CAPEX vs OPEX” do you not agree with? I’m no economist, but this sounds interesting.

In a very brief nutshell, the ways in which buying a little hardware or a tool to save thousands of hours of frustrating development work is not a slam dunk because of colors of money.

In either case, you still have to compare against using the fossil fuels to heat your house instead of turning them to electricity first, to heat your house via the heat pump or the resistive heater

This video does a great job at considering that aspect: https://youtu.be/MFEHFsO-XSI

In that case you would still have an absorption refrigerator that "cools" the outside and dumps to the inside as an alternative. They are usually either gas-fired or running off of district heating (well, 50-120C seems usual).

For bitcoin mining to pay for itself, you need to leave it running to the max 24/7. Each miner is a noisy ~3000w machine. So that's a 3000w heater. You would normally turn down the heater during the day, but if you turn off your miner during the day, you won't break even.

Apparently you haven’t heard of immersion cooling. It’s essentially silent, and many people are using DIY setups to augment a heat pump or hot water heater.

Commercial solutions have been in development for a few years. Here’s one example: https://www.wisemining.io/

Edit: after re-reading your comment I realize you also aren’t aware that miners can be throttled. Powering it down is not the only alternative to consuming 3kW.

It pays for itself in dollars but what about the carbon emissions?

If you live in Siberia you presumably want the planet to warm up more. ;)

> If you live in Siberia you presumably want the planet to warm up more. ;)

No you don't, when permafrost melts it causes ground to move. It is really bad for everything build on or in it. Something like houses sinking and falling apart. In some cases it cause big holes in the ground and they got even bigger over time.

Most of Siberia does not have permafrost, though.

Because permafrost melting is the only negative consequences of climate change. There are no forest fires, no problems with insect due to milder winters, etc.

Do you really think anyone in Siberia, one if the poorest places in the world, cares about carbon emissions?

My point is that when we as outsiders look at this practice and evaluate its merits, we should care about the carbon emissions even if the people there don’t.

> Do you really think anyone in Siberia, one if the poorest places in the world, cares about carbon emissions?

Unfortunately they care. For now only poor face real consequences of climate change. They are to poor to mitigate its effects.

It seems Siberia is one of the places where living conditions might actually improve https://eos.org/articles/climate-change-could-make-siberia-a... (the "big bog" scenario does cast doubt on that -- e.g. existing structures may collapse).

There are sinkholes appearing due to permafrost melting and ice keeps ground solid, otherwise there would be mud(and sinkholes) all over the place.

The problem is almost noone there can afford a heatpump

For a guy in Siberia various climate models show that the global warming will improve life. Winters will be much milder, agriculture will be less risky.

My understanding is that this isn't true, because Siberia's muskeg soil isn't very suitable for growing things, whether frozen or not. (Same with northern Canada. Muskeg and mosquitos are why northern Ontario has never been settled.)

I'd assume that they were going to use carbon-generating fuel, and that someone somewhere would already run a mining rig. IE: It's murky.

If they were going to heat using an electric space heater, it's a wash.

If they were going to heat using natural gas, but the electricity comes from nuclear, it's lower carbon.

If they were going to heat using natural gas, and the emissions are higher. BUT, if they were going to run the mining rig anyway, and they've merely turned off the gas heat, the emissions are overall lower.

They could heat with an electric heat pump with can be 2.5x more efficient than an electric heater.

But heat pumps don't pay you to run them! (I wish mine did.)

I understand this, but the argument I was responding to was "you're already going to use the electricity, you might as well make profit", but actually you could use less energy so it's not a given that all this electricity was going to be used. It is instead a choice between profit and carbon emissions.

Which is really interesting because electric space heaters are 100% efficient.

Yes, heat pumps use 1 watt to apply 2.5 watts of heat to a room (by using the outdoor ambient air as an energy source).

(Apologies if you already know this.)

Heat pumps work by moving heat, they usually move more heat than input energy.

Basically, a refrigerator is a heat pump. The input energy runs the heat pump, which it uses to move heat out of the refrigerator. Typically, for every watt of electricity, more than a watt of electricity is moved out of the refrigerator.

They work by compressing gasses into fluids, and then letting the fluid expand back into a gas. Basically, when a fluid evaporates, it absorbs heat as potential energy. The energy can be harvested by compressing the gas at a high enough pressure that it condenses into a fluid. Do this in a loop, and you can move heat.

No laws of physics violated!

Or an example that might be more readily acceptable, being something that a person without any domain knowledge could simply test* to prove it to themselves:

Suppose you built a shed around the outdoor unit of a central air conditioning system and let it come up to max ambient temperature. Then right next to it you built a shed with a resistive heater which consumes the exact same wattage as the air conditioner. The first shed will be much warmer because you're not creating heat so much as you're moving heat. If you increase the resistive heater's wattage by about 2.5x then the sheds will be about the same temperature.

* Don't actually do this and expect the system to survive.

Why would we assume they are (I'm not sure that the "someone somewhere" part of that is material either) going to use a mining rig already to assess the merits of mining rigs for heating? That's tautological.

A lot of places that do electric resistive heat have cheap electrical sources - often hydro or nuclear.

You can still use a heat pump that takes the heat from the exhaust air to warm the fresh air. That way you can get the same amount of heat as if you were using three+ times as many graphics cards.

I usually use GPUs for heating during winter as the power has to be used anyway, so why not get ethereum for it.

> You can still use a heat pump that takes the heat from the exhaust air to warm the fresh air

Unless I'm misunderstanding part of this proposed setup, I'm pretty sure this doesn't work. The higher efficiency of heat pumps comes from the fact that the outdoors is an effectively infinite (for the purposes of a house) source of temperature differential. You can only move as much heat as exists, so you can't use a heat pump to multiply a finite heat source.

I'm not sure what there is to misunderstand. Heat is taken for the outgoing hot air, and transferred to the fresh air coming in. So instead of hot air going out, the air going out will usually be freezing.

That sounds like heat recovery ventilation; while useful, it serves a different purpose than heat pumps (which heats up enclosed spaces without the ventilation). Also HRVs normally work with whatever existing air and don't use extra heated air…

You are recovering the heat from the ventilation, yes. But you're doing so using a heat pump.

Check out e.g. Nibe F750 with SAM40.

I'm using the heat pump to heat water using the extracted air. That water is then used for floor heating, ventilation air heating and ofc. hot water.

In my experience, people usually try to avoid exchanging air with the outdoors when they're concerned about significantly heating/cooling their homes. If you're exchanging air then a heat pump could super heat/cool the outgoing air, and that's the piece I was missing from your proposal.

A house must exchange air. Better insulated houses are basically air tight, so you must have ventilation to get fresh air.

A pro with that solution is that the extracted air has a high temperature all year, making it more efficient that using a heat pump to extract heat from outside that might be -30 celcius. A downside is that the amount of air is limited, so if you need more heat then you have to supplement it with something else.

You get it, but it seems there are a few others that don't realize that a heat pump can also be used to increase efficiency by reducing the heat lost. While I do get that it's unknown to most people, some people here perfectly illustrates the Dunning-Kruger effect...

> You can still use a heat pump that takes the heat from the exhaust air to warm the fresh air.

I don't think you understand how heat pumps work. Heat pumps have significantly greater than 100% "efficiency". They don't turn electricity into heat. They use electricity to move preexisting heat, and it turns out that's far more efficient in terms of Joules of heat delivered to your home per Joule of energy spent. In fact, for any given Joule of energy spent, you can generally move two to three Joules from outside your home to inside of your home.

If the source of heat you're pumping is coming from resistive heating you're using electricity for, you're only getting 1 Joule of heat for every Joule of electricity. Adding heat pumps to this system doesn't help you.

> I usually use GPUs for heating during winter as the power has to be used anyway, so why not get ethereum for it.

Because owning and operating a heat pump is almost certainly cheaper than the costs of owning and operating a mining rig, even offset by the value of the cryptocurrency you generate. You'd almost certainly be better off by heating your home with a heat pump and using the energy savings to buy that same cryptocurrency.

The exceptions to this are if you are in a location where energy is extremely cheap, or perhaps if you generate more than your household usage of electricity (including resistive heating) through solar or wind but aren't able to sell that electricity back to the grid.

I know very well how heat pumps work, and I find it ironic that you assumes others don't know because you don't understand it or haven't heard of it.

A heat pump doesn't have to take heat from the outside. By using heat from the extracted air, you can use whatever you want to generate heat inside and get multiple times the effective heating as it's reused. Use wood, electrical floor heating or GPUs. It doesn't matter. The energy from the extracted air is transferred to the fresh supply air. The exhaust air will be freezing.

Also, electricity has been expensive the last two years, but mining has still been profitable, considering I already have some GPUs in my workstation and home server.

You don't earn money by using a heat pump, you do(or at least did) by mining. By mining and using a heat pump on that energy I increase the usage of that energy. Win win win.

> I know very well how heat pumps work, and I find it ironic that you assumes others don't know because you don't understand it or haven't heard of it. > > A heat pump doesn't have to take heat from the outside.

If you're already spending 1J of energy to get 1J of heat, a heat pump is not going to turn that 1J of heat into 2-3J of heat, nor is it going to recover any of the Joules you've spent to generate that heat. So sure, you can use a heat pump to move that heat around a space. But doing so just spends more energy and decreases the overall efficiency of the system.

The principle of a heat pump getting such efficiency numbers is entirely predicated upon the notion that you're able to move that heat from somewhere it already exists "for free" in sufficient bulk.

> You don't earn money by using a heat pump, you do(or at least did) by mining. By mining and using a heat pump on that energy I increase the usage of that energy. Win win win.

You fundamentally misunderstand the economics of this situation. Mining costs money in the form of hardware and electricity. In exchange you can potentially extract some amount of revenue. If your alternative was to use that energy to generate one Joule of heat for every Joule of energy spent, you might as well mine to get a rebate.

But the sum of mining revenue minus mining costs are almost certainly less than the costs of simply operating a heat pump instead. Again, you'd be better off using a heat pump to heat your home and using the money saved on energy to simply buy $CRYPTO at market prices.

As I said, I already have GPUs. If you don't think mining has been profitable for me and others during e.g. the last year then you need a reality check, cause it has been profitable.

> If you're already spending 1J of energy to get 1J of heat, a heat pump is not going to turn that 1J of heat into 2-3J of heat, nor is it going to recover any of the Joules you've spent to generate that heat.

It's not magic, or complicated. The energy spent is used multiple times, as I said. You can save energy using a heat pump both by using it for initial heating, or transferring existing heat that would otherwise be thrown away.

So no, I'm not misunderstanding anything. If you think it's not possible then you too can get this "magic" using e.g. Nibe F750 + SAM40. Check their documentation, it even has charts for everything!

Why would you be throwing away the heat? You're not exhausting the warm air outside, are you?

There was a comment on another web site a while back: "The words you're using - it's like you know what a microwave is, but you keep calling it a fridge, and you want that fridge to do an oil change on your cat."

You insist you know about heat pumps, but your comments indicate you don't understand the fundamental principles.

It's an interesting topic, if you find the time.

The Mitsubishi Mr Slim heat pumps that we install are able to warm your home in temperatures as low as -15°C and -25°C

When temperatures drop below zero degrees, ice will build up on the outdoor unit of any heat pump. How the heat pump reacts to this determines how effective it will be in providing heat to your home. To remove the ice build-up the heat pump will need to go into Defrost Mode. During this time the heat pump will not be delivering heat into your home. HyperCore’s Defrost Logic has been fine-tuned to extend the period in-between defrost periods and optimise its heating performance.

Mitsubishi Electric offers heat pump systems with Hyper-Heating INVERTER® (H2i®) technology which can provide up to 100 percent of heating capacity at 5° F and continue operation down to -13° F even wiThe Mitsubishi Mr Slim heat pumps that we install are able to warm your home in temperatures as low as -15°C and -25°C thout auxiliary heat.

https://www.mitsubishicomfort.com/articles/what-is-a-heat-pu...

https://www.mitsubishi-electric.co.nz/materials/aircon/broch...

Until 100% of our electricity is provided by renewables or nuclear, resistive heating is just turning converting fossil fuels into heat, which we convert into electricity, which we convert back into heat. It would be more efficient to just burn the fossil fuels on site.

You’re ignoring heat pump technology, which can result in greater overall efficiency than converting energy directly to heat.

The parent comment already addresses heat pumps. I'm explaining that there is virtually 0 practical use case for using mining to heat people's homes.

that assumes the use/utility of the computation is 0. We can all debate if that's true or not about cryptomining.

One day we may heat our homes with distributed computing like BOINC.

Consider the house that marginally has electrical resistive wall heaters (Like the bay area) and an excess of spare computers sitting around (also like the bay area) ... It's marginally better for the house nerd to leave their PCs on using BOINC than run the wall heater.

If by mining, you mean cryptocurrency creation, the utility is effectively 0. You can achieve the same utility if a cryptocurrency simply credited all new coins to my wallet. If by mining, you mean validating transactions, then that's something you have to do all year round, even if it's warm. That makes about as much sense as asking VISA to send me a rack that does computations for them only when my home is under 20 C.

yes, which is why the rest of my comment was about BOINC

Burning fossil fuels on-site means transporting fossil fuels to people's houses. Natural gas has a GWP which is 21 times that of CO2, and residential natural gas distribution systems are responsible for massive emissions just due to the leaks.

>> more efficient to just burn the fossil fuels on site.

You forget exactly how efficient a coal-fired powerplant actually is. Love or hate them, they have 100+ years of technological innovation to squeeze every watt out of coal. Your fireplace at home is not nearly as efficient. So an electric heater powered by the grid is almost certainly more efficient than burning your own coal at home in an inefficient stove.

A good oil-burning heater has over 90% efficiency. Even no so good and cheap one can get over 70%. The best industrial electricity-generating plants that runs on oil has efficiency bellow 60%.

Does that oil-burning heater need oxygen? If it does then it needs ventilation, air movement in/out of the house, pushing that 90% efficiency number way down.

Tech connections has what you're looking for: https://youtu.be/lBVvnDfW2Xo

Efficiency wise, the comparison between a heat pump and a furnace depends on the outside temperature. Heat pumps lose their efficiency for high ∆T, so for winter in a Russia, a furnace is likely the better option

90% is overtall efficiency including losses due to ventilation. Such system with its heat exchangers is not cheap, but long term it pays off compared with less advanced heater.

Unless you assume CCS for the fossil plant, which is not a setup that would work well for a typical residential forced-induction gas-fired central hot water heater (combined with passive radiators in rooms or underfloor heating).

This is pretty common. I've been using my gaming rig for cryptomining in cold weather for years. I make money and keep my office warm, win win.

Ah, money laundering, the international past-time-space-crime.

This was the best blog I ever noticed on this topic,an Australian using exhaust air from their miners to pre-heat incoming air to their heat pump. TL;DR - it's worth it.

https://blog.haschek.at/2021/how-i-heat-my-home-by-mining.ht...

Is this the reason of global warming?

The Russian energy grid doesn't really have a reputation for being carbon neutral...

Don't they have more nuclear poweplants than most places in the west?

Might be more, but it's still a minority of their grid. Wikipedia has a graph for 2016: 18.1% nuclear, 47.9% natural gas, and 15.7% coal.[0]

"Energy Matters" says that EU energy production was 26% nuclear in 2015, but only 12% for consumption[1], so I'm not sure how to look at that comparison. Either way, that's probably mostly France (~80%[2]). US around 8-9%[1].

TL;DR: Yes, most western countries probably have less nuclear, but it's a low bar.

[0] https://en.wikipedia.org/wiki/Electricity_sector_in_Russia#M...

[1] http://euanmearns.com/primary-energy-in-the-european-union-a...

[2] https://en.wikipedia.org/wiki/Electricity_sector_in_France#M...

Russian nuclear is ~17% (compare US at 19%). Overall it is slightly less CO2-intensive than the US, as it uses less coal. They have almost as much hydroelectric power as the entire US renewable sector.

They have a sizeable nuclear electricity production, and in energy use overall they are behind USA, but still worse than many other places:

https://data.worldbank.org/indicator/EN.ATM.CO2E.PC?end=2018...

As much as you living in a steel reinforced concrete house.

There are those that day global warming is caused by politicians talking crap about global warming. My theory is global warming is caused by the people that vote for the politicians that talk crap about global warming.

Cryptocurrency is not even 1% of global energy consumption. The environment is being destroyed by China, western nations, fossil fuels. If anything cryptocurrency is just a very small drop in their bucket.

1% of global energy usage is an insanely high number for something like this. 1% is absolutely not a drop in a bucket.

Something completely useless like bitcoin, absolutely. I wouldn't mind even more energy being poured into Monero though.

Monero is almost solely use for crime. Most exchanges won't touch it, and that's a good thing because it would pour fuel on top of the existing cryptocurrency-enabled ransomware trash fires, if it was actually usable.

So? If some criminal usage is the price we must pay for real privacy, so be it. Total warrantless surveillance is the greater crime.

If we were talking about petty crime, I may agree with you, but cryptocurrencies enable ransomware, which frequently shuts down critical services like hospitals and schools. Ransomware attackers have also leaked personal medical records from hospitals, and student's private records from schools.

Surveillance is an issue, but for the most part, it's not warrantless in our current system. Cryptocurrencies, excluding things like Monero and Zcash actually make it considerably easier to do warrantless surveillance.

If I'm forced to choose between some instances of illegal warrantless surveillance, and the complete inability to trace financial crimes, I'll take the instances of illegal surveillance, with the hope we'll try to fix those issues.

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