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Thermoelectric heating stands at the brink of commercialization

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Re: Thermoelectric heating stands at the brink of commercialization

#31

Post by fy20 »

antisthenes wrote: post #11
skyfaller wrote: post #7

Earlier quoted context omitted.

To steelman your proposal, I should mention that Low-Tech Magazine thinks you're on to something, although they suggest putting the panels on the stove inside the cabin: https://solar.lowtechmagazine.com/2020/05/thermoelectric-sto... I disagree with that article for the simple reason that I do not consider burning wood to be sustainable, or healthy for anything with lungs. Wood should be used for long-lasting constru…

Most burned wood is wood unsuitable for construction. No one goes into the woods and cuts down a 200-year oak to burn in their stove. Short lengths, widths, knots, imperfections, wood waste pressed into pellets, etc. Although you do have a point about it being bad for air quality. Especially old stove installations.

Here in Europe there is so much demand for wood that forests are being grown just to be cut down and turned into pellets - it's not just waste that goes into them.

Maybe it's not as bad as fossil fuels, but it still has the same issues as commercial monoculture farming, which is why there are issues with bark beetles now. And most of these forests start by tearing down old growth forests.

Re: Thermoelectric heating stands at the brink of commercialization

#32

Post by Kye »

davidw wrote: post #30

We recently got a heatpump and... it feels like witchcraft. It chugs away even at 20F blowing hot air into our house.

At 20F that's probably the backup heat kicking in. Heat pumps start losing their efficiency advantage around 40.

edit: apparently I was misinformed, but it doesn't seem like something worthy of being downvoted into oblivion.

Re: Thermoelectric heating stands at the brink of commercialization

#33

Post by Scoundreller »

pishpash wrote: post #18
Retric wrote: post #16

Earlier quoted context omitted.

You’re allowed to make use of the same energy at different points in time. The 1% used by the fan is the same 1% that’s heating your room. A computer converts 99.9% of the electricity to heat a room just like a space heater. However, you can play video games on the PC while it’s heating your room.

That's why all electric heating should be devices that do work or compute. Do not waste the Gibbs free energy of the universe.

I want a cottage industry of aluminum smelters in cold climates.

Pick up a pile of aluminum oxide from a depot, electrolyze it into aluminum at home, and drop off the finished aluminum at the depot for a cheque that covers your electricity.

"The theoretical minimum energy requirement for this process is 6.23 kWh/(kg of Al), but the process commonly requires 15.37 kWh."

https://en.wikipedia.org/wiki/Hall%E2%80%93H%C3%A9roult_proc...

That's quite a few kWh of heat per kg of finished product. You're going from Al2O3 to Al, so your returns will weigh less than your pickups.

Comparable to coal or oil heat:

"With a complete combustion or fission , approx. 8 kWh of heat can be generated from 1 kg of coal, approx. 12 kWh from 1 kg of mineral oil"

https://www.euronuclear.org/glossary/fuel-comparison

Re: Thermoelectric heating stands at the brink of commercialization

#34

Post by deedubaya »

bilsbie wrote: post #4

I’d pay a premium for a solid state AC or heat pump. It’s absurd how much they cost to install. And I don’t get why replacing one is an all day job for three people. There should be standard connections they just plug into. Like a dishwasher.

I was just last month quoted 15-23k for an install in the mountains of Idaho. I got a competitive quote and the price was similar.

If it cut my electricity bill in half it would take 10-20 years to break even.

Re: Thermoelectric heating stands at the brink of commercialization

#35

Post by andbberger »

pishpash wrote: post #18
Retric wrote: post #16

Earlier quoted context omitted.

You’re allowed to make use of the same energy at different points in time. The 1% used by the fan is the same 1% that’s heating your room. A computer converts 99.9% of the electricity to heat a room just like a space heater. However, you can play video games on the PC while it’s heating your room.

That's why all electric heating should be devices that do work or compute. Do not waste the Gibbs free energy of the universe.

this was the only sane argument for blockchain mining but it was never competitive with heat pumps

Re: Thermoelectric heating stands at the brink of commercialization

#36

Post by ChatGTP »

antisthenes wrote: post #9
bilsbie wrote: post #4

I’d pay a premium for a solid state AC or heat pump. It’s absurd how much they cost to install. And I don’t get why replacing one is an all day job for three people. There should be standard connections they just plug into. Like a dishwasher.

What in the world are you talking about? The hardest part of installing AC is the ductwork. Swapping out the outside + inside heat exchanger unit is a 1-person 3-4-hour job. Sorry if some HVAC company scammed you, but it's definitely not a 3 person job, unless we're talking some commercial building 5+ ton units.

If you're system is hooked up to "floor heating", hydraulic stuff that runs under your floor it's still a one man job but can be a little bit harder to do.

Re: Thermoelectric heating stands at the brink of commercialization

#37

Post by Scoundreller »

andbberger wrote: post #35
pishpash wrote: post #18

Earlier quoted context omitted.

That's why all electric heating should be devices that do work or compute. Do not waste the Gibbs free energy of the universe.

this was the only sane argument for blockchain mining but it was never competitive with heat pumps

Depends how cold it is outside, but yes, heat pumps usually win.

Re: Thermoelectric heating stands at the brink of commercialization

#38

Post by davidw »

Kye wrote: post #32
davidw wrote: post #30

We recently got a heatpump and... it feels like witchcraft. It chugs away even at 20F blowing hot air into our house.

At 20F that's probably the backup heat kicking in. Heat pumps start losing their efficiency advantage around 40. edit: apparently I was misinformed, but it doesn't seem like something worthy of being downvoted into oblivion.

No, because the installer set it up right at 20. We do have a gas furnace that kicks in below that.

It'd be amazing if someone put together some kind of dynamic calculator that could take electricity and natural gas prices and examine inside temperatures based on a smart thermostat system and rejig the cutoff temperature based on all of it.

Re: Thermoelectric heating stands at the brink of commercialization

#39

Post by patmorgan23 »

davidw wrote: post #38
Kye wrote: post #32

Earlier quoted context omitted.

At 20F that's probably the backup heat kicking in. Heat pumps start losing their efficiency advantage around 40. edit: apparently I was misinformed, but it doesn't seem like something worthy of being downvoted into oblivion.

No, because the installer set it up right at 20. We do have a gas furnace that kicks in below that. It'd be amazing if someone put together some kind of dynamic calculator that could take electricity and natural gas prices and examine inside temperatures based on a smart thermostat system and rejig the cutoff temperature based on all of it.

Bet you could do this in home assistant

Re: Thermoelectric heating stands at the brink of commercialization

#40

Post by tempestn »

Kye wrote: post #32
davidw wrote: post #30

We recently got a heatpump and... it feels like witchcraft. It chugs away even at 20F blowing hot air into our house.

At 20F that's probably the backup heat kicking in. Heat pumps start losing their efficiency advantage around 40. edit: apparently I was misinformed, but it doesn't seem like something worthy of being downvoted into oblivion.

Modern cold-climate heat pumps can definitely handle 20F. Yes they're more efficient at higher ambient temperature, but you can get at least 2.5 COP at 20F. (And good ones can continue to outperform resistive heating at much lower temperatures than that.)
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