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I heat my home by mining crypto currencies

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Re: I heat my home by mining crypto currencies

#391

Post by imtringued »

amackera wrote: post #304
danans wrote: post #288

Earlier quoted context omitted.

No, because a CPU isn't a consumable resource, like electricity or labor. You should occupy the CPU with all valuable work (for whatever definition of value) but keeping it pegged for no reason makes no sense, and just wastes electricity.

In a way, by not running useful work 100% of the time, you're wasting the resource of time.

If my phone or laptopbattery dies on me I could lose a lot more time/money than by simply not wasting precious resources like battery charge. People buy devices for specific needs. If they can't meet those needs the purchase is a net negative.

Re: I heat my home by mining crypto currencies

#392

Post by yarcob »

noxer wrote: post #235

Someone clearly doesn't understand thermodynamics at all if he seriously thinks putting that thing outside and let the warm air be sucked in, is more efficient that running it inside. for obviously reasons (isolation loses/heat radiation) more energy (heat) is lost outside than inside (inside has zero loses because even the heat that doesn't go where you want it, still is inside the house.)

- He mentioned that mining is more efficient when the GPUs are cooler, so using them to pre-heat outside air is better than using them to heat up room temperature air.

- since he would be forcing a lot of air through the miner, almost all heat would be transferred into the house using convection. The miner would stay cool and there would be very little radiation loss.

- finally, his ventilation system probably needs pre-heating on very cold days (often with a resistive pre-heater). Using the miner for that is smart.

Re: I heat my home by mining crypto currencies

#393

Post by OJFord »

drran wrote: post #384
OJFord wrote: post #302

Earlier quoted context omitted.

> or heat taken in.

Ambient heat is not a "heat taken in", because you don't need to supply it. Usually, heat is taken out from the system and dissipate as ambient heat, so a heat pump can use the same heat again and again, without exhausting of ambient heat.

Of course you need to supply it, you wouldn't use one in Antarctica . (I'm no refrigerant expert, but I assume there's nothing that would work well enough to be worthwhile.)

The only reason I can think of for 'or heat taken in' in that definition is exactly to stop people claiming >100% efficiency for heat pumps, which is a corollary for perpetual motion, and equal nonsense.

> so a heat pump can use the same heat again and again, without exhausting of ambient heat.

That's just not true, they are heat interfaces, thermal energy is transferred from outside to a refigerant, to inside (or inside water, or whatever).

If this were true, they would have a closed tank of hot air as well as a closed refigerant loop (as the vast majority do) so it would always be oprrating optimally in any environment, never running out of hot air.

The clue's in the name - pump! - they just move heat about, you wouldn't claim pumping water is >100% efficient because you're creating water out of nothing and you'll never run out of water in the infinitely massive lake you're pumping from, would you?

Put a box over it. Look at what goes into the box and what comes out, on all sides. Efficiency = Outs / Ins. It's a yield. A ratio of how much of what you put in you get back out in the form you want.

Re: I heat my home by mining crypto currencies

#394

Post by Nextgrid »

tom_mellior wrote: post #158
Nextgrid wrote: post #86

Earlier quoted context omitted.

The proof of work in tokens has to be a net waste of energy; the idea is that the proof of work is costly enough to prevent a 51% attack. Making the proof of work do “useful” things would lower the cost of said work thus lowering the barrier of entry to an attack.

> Making the proof of work do “useful” things would lower the cost of said work thus lowering the barrier of entry to an attack. How does this follow? If the work is so universally useful that it lowers the cost of the work, it lowers the cost for everyone . Not just "attackers", but "defenders" as well. As it happens, Bitcoin miners mine not out of the goodness of their hearts but for financial profit. Bitcoin POW i…

The problem is that the usefulness of said work might not be the same to everyone. Let's imagine a potential coin where mining involves cracking hashes.

This work is useless to you and me (thus the only extracted value would be the reward from mining), but might be useful to someone who's got hashes to crack (so they get extra value out of the same process). In this case, the latter party can enjoy a 51% attack at a fraction of the cost of the former.

Re: I heat my home by mining crypto currencies

#395

Post by noxer »

yarcob wrote: post #392
noxer wrote: post #235

Someone clearly doesn't understand thermodynamics at all if he seriously thinks putting that thing outside and let the warm air be sucked in, is more efficient that running it inside. for obviously reasons (isolation loses/heat radiation) more energy (heat) is lost outside than inside (inside has zero loses because even the heat that doesn't go where you want it, still is inside the house.)

- He mentioned that mining is more efficient when the GPUs are cooler, so using them to pre-heat outside air is better than using them to heat up room temperature air. - since he would be forcing a lot of air through the miner, almost all heat would be transferred into the house using convection. The miner would stay cool and there would be very little radiation loss. - finally, his ventilation system probably needs…

>He mentioned that mining is more efficient when the GPUs are cooler...

Its simply not true. GPUs dont work fast or slower based on temp as long as the temp is in the rated range. It could potentially save energy by spinning the fans slower if the air around is super cool but the energy savings from that would be incredible small.

>since he would be forcing a lot of air through the miner, almost all heat would be transferred into the house using convection. The miner would stay cool and there would be very little radiation loss.

That's also not how thermodynamics work. The greater the temp differences are the more heat will be lost. The air need time to pick up the heat so you have a partially open box full of warm air outside that will heat up everything around it and possibly radiate heat directly in the sky unless it is extensively isolated. But even then you cant effectively isolation the air intake.

>- finally, his ventilation system probably needs pre-heating on very cold days (often with a resistive pre-heater). Using the miner for that is smart.

Sure, using the miner _outside_ is the not smart part.

Re: I heat my home by mining crypto currencies

#396

Post by LocalH »

CobrastanJorji wrote: post #300
seniorsassycat wrote: post #297

Earlier quoted context omitted.

A heat pump in a −273 °C space will convert electricity to heat at a 1:1 ratio. If you count the heat taken from the space around the condenser, which you should based on Google's definition, heat pumps are only 100% efficient. Calling heat pumps >100% efficient is like calling my solar water heater >100% efficient. True if you only count the electrical input, and not other sources of energy.

You will be pleased to know that the majority of heat pumps are installed in homes whose exteriors stay above 0 kelvin year round. Also, in what I assume is an efficiency feature, most heat pumps do not allow operation in a zero Kelvin environment. Also, to nit pick: Kelvins are not degrees and do not use a ° sign.

Good thing they wrote −273 °C and not "0 °K".

Re: I heat my home by mining crypto currencies

#397

Post by IneffablePigeon »

tialaramex wrote: post #381
IneffablePigeon wrote: post #274

Earlier quoted context omitted.

This is an interesting topic - I agree with your interpretation, but to add another wrinkle, I live in the UK which has a decent but not amazing proportion of renewable energy now. I pay a little extra to my supplier to provide me with "100% renewable electricity" - meaning that for every customer on that tariff, they total up the power usage and buy at least that much renewable energy from the grid. I assume that th…

"100% renewable electricity" obviously doesn't change where the electricity you actually use comes from. We certainly don't want the lights to go out and our oven to stop working just because it's a cold still night and all the hydro was used up. You would need to check the supplier's fine print very carefully if you actually decide you care what this means. The consumer magazine "Which" have attempted that for you i…

Thanks for the in depth answer - pretty much what I suspected. I think this sort of thing only even starts to work when you have a critical mass of people on this kind of tarriff (and more than that, willing to pay more and/or switch supplier for it). I wonder what actual proportion of the UK market is currently on a "100% renewable" plan.

Re: I heat my home by mining crypto currencies

#398

Post by cgufus »

throw0101a wrote: post #345
shoo_pl wrote: post #85

Earlier quoted context omitted.

On principle, yes. There are quirks - the COP is different for lower temperatures, and becomes 1:1 at around 5F (-15C). So preheating the air could improve the effectiveness at low temperatures, and I am guessing it might look like this: - before: 1kWh in, 1kWh out - after: 1.9kWh in, > 1.9kWh out However, if it was that simple, I suppose heat pump manufactures would include a pre-heating as built-in feature. It's ve…

> There are quirks - the COP is different for lower temperatures, and becomes 1:1 at around 5F (-15C). It depends on the unit. Some (Mitsubishi FE12NA) have a COP of 1.75 even at -10F / -20C. See Table 6: * https://www.nrel.gov/docs/fy11osti/52175.pdf

The used coolant mainly infleunces these numbers.

check chart on: https://www.researchgate.net/figure/Coefficient-of-performan...

Re: I heat my home by mining crypto currencies

#399

Post by yarcob »

noxer wrote: post #395
yarcob wrote: post #392

Earlier quoted context omitted.

- He mentioned that mining is more efficient when the GPUs are cooler, so using them to pre-heat outside air is better than using them to heat up room temperature air. - since he would be forcing a lot of air through the miner, almost all heat would be transferred into the house using convection. The miner would stay cool and there would be very little radiation loss. - finally, his ventilation system probably needs…

>He mentioned that mining is more efficient when the GPUs are cooler... Its simply not true. GPUs dont work fast or slower based on temp as long as the temp is in the rated range. It could potentially save energy by spinning the fans slower if the air around is super cool but the energy savings from that would be incredible small. >since he would be forcing a lot of air through the miner, almost all heat would be tra…

> GPUs dont work fast or slower based on temp as long as the temp is in the rated range

Correct me if I'm wrong, but I assumed that mining would quickly cause the GPU to reach the maximum temperature, at which point it would automatically throttle. The performance mainly depends on the cooling power. And air at -10°C will cool a lot more efficiently than air at 20°C. (I'm assuming the ventilation would move a roughly similar amount of air through the miner as the normal fans, which may or may not be a sensible assumption)

> The air need time to pick up the heat so you have a partially open box full of warm air outside

As far as I understood he's planning to pull the cold outside air through the miner. The warm air inside the miner would immediately be pulled inside the house.

I assumed that the amount of air used by the ventilation system of the whole house is enough to keep the miner pretty cool. The GPUs would get hot, but since a lot of air is moving through the outside of the miner would not get very warm at all.

I mean, yes, depending on where he places the miner and how long the hose to the air intake is, there will obviously be some lost energy. But I don't think it's as stupid as you say.

Especially since there is probably not a lot of space to put it inside the house, as typically the heat exchanger is very close to the air intake, to avoid long ducts with cold air inside the house.

Re: I heat my home by mining crypto currencies

#400

Post by zirkonit »

420codebro wrote: post #182
zirkonit wrote: post #140

Earlier quoted context omitted.

Another one: Yandex (disclosure: the company I work for) is using one of its datacenters to heat the entire town it is in. Proof: https://helsinkismart.fi/case/waste-not-want-not-data-center...

Interesting. Never ran across someone who worked for Yandex. Overall are you happy with your employer?

Absolutely! By any definition, the pinnacle place to work for in Russia.
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