Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Thermoelectric heating stands at the brink of commercialization

spectrum.ieee.org

Post reply on HN
Print view View original

81–90 of 126 posts

Re: Thermoelectric heating stands at the brink of commercialization

#81

Post by wanderingbit »

c_o_n_v_e_x wrote: post #55
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.

>And I don’t get why replacing one is an all day job for three people. Let's go through the whole process. You need a system changeout for a ducted central HVAC system. Someone comes over and gives a bid. You accept. Your HVAC person needs to go to a supply house and purchase all of the parts and bring them to your residence in a vehicle than can hold everything. Assuming you have an existing system, the refrigerant…

It is detailed comments like this that make me feel very fortunate for the community here. Thank you!

Re: Thermoelectric heating stands at the brink of commercialization

#82

Post by speed_spread »

VBprogrammer wrote: post #80
deedubaya wrote: post #34

Earlier quoted context omitted.

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.

> If it cut my electricity bill in half it would take 10-20 years to break even. Presumably there is a useful life on your existing heating system. At some point it would need replacing?

Assuming electricity is already used for heating, baseboards heaters are just big resistors and have basically unlimited life.

Re: Thermoelectric heating stands at the brink of commercialization

#83

Post by elil17 »

As someone who works in this industry - no, thermoelectric heating does not stand at the brink of commercialization. The fundamental issue with thermoelectric heating is that you need a material with high electrical conductivity but very low thermal conductivity. zT is a metric that measures this ratio. Conducting electricity but not heat is a weird property for a material to have and no one even knows if zT can be raised much from where it is today. Even if it could, it would probably be expensive, so you'd probably want to use thermoelectric cooling for things like on-chip computer cooling, not to cool your whole house.

Re: Thermoelectric heating stands at the brink of commercialization

#84

Post by deedubaya »

tempestn wrote: post #43
deedubaya wrote: post #34

Earlier quoted context omitted.

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.

For a mini-split system, or central heat pump? Do you have existing ducts? What's the square footage? We recently upgraded our central heat pump as the old one died after 15 years or so. IIRC the total was $13k CAD, so around 9-10k USD, which included indoor and outdoor units for a roughly 3000sqft house, with installation. But all the ducting was there already, so it was just a matter of swapping out old unit for ne…

Central, augmenting existing electric forced air with existing ducts. Similar sized home.

Re: Thermoelectric heating stands at the brink of commercialization

#85

Post by kwhitefoot »

pjc50 wrote: post #67
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.

Replacing like for like should be a fairly easy job. But replacing between different systems does seem to be a nightmare. It's interesting that Americans are retrofitting them into HVAC systems, while in the UK we're trying to retrofit into natgas/water based systems, and seemingly the Scandinavians have gone for .. I'm not sure but it seems cheaper? I upgraded to a "hybrid" system because it was the least cost / min…

In Scandinavia we use air to air heat pumps. We generally don't have central heating of any kind so we aren't so tempted to try to shoehorn the heat pump into a system based on hot water.

Air to air is much cheaper and is more efficient because it doesn't need to raise the temperature of the working fluid so much and doesn't require a big fluid to water heat exchanger.

I'm having a Toshiba Polar 35 heat pump installed soon. Nominal output 3.5 kW, maximum output 7 kW. The total cost is 28 kNOK, about 2.6 kUSD, 2 kGBP. Should be enough for the whole ground floor of about 80 square metres.

Re: Thermoelectric heating stands at the brink of commercialization

#87

Post by quickthrowman »

thsksbd wrote: post #54
ctechbob wrote: post #50

Dupont will see that this never sees the light of day. Just like how we don't use butane/propane/CO2 as refrigerants which are just as safe as most of the flourocarbons but have the downside of being too cheap to make any money off of.

Well they're also inflammable and not as good as CFCs. Kinda how we don't use toxic ammonia as a refrigerant. For what it's worth, my mini fridge and my chest freezer use some hydrocarbon refrigerant. They're littered with warning signs not to puncture them.

> Kinda how we don't use toxic ammonia as a refrigerant.

Ammonia is definitely still used as a refrigerant, just not in consumer equipment. It’s commonly used for ice rink chillers, at least in the US and Canada. Not sure about Europe.

Re: Thermoelectric heating stands at the brink of commercialization

#88

Post by stetrain »

pjc50 wrote: post #67
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.

Replacing like for like should be a fairly easy job. But replacing between different systems does seem to be a nightmare. It's interesting that Americans are retrofitting them into HVAC systems, while in the UK we're trying to retrofit into natgas/water based systems, and seemingly the Scandinavians have gone for .. I'm not sure but it seems cheaper? I upgraded to a "hybrid" system because it was the least cost / min…

It's fairly common in the US to have central AC plus a gas furnace. Retrofitting the AC with a heat pump lets you move away from the gas system.

Re: Thermoelectric heating stands at the brink of commercialization

#89

Post by leoedin »

skyfaller wrote: post #7
grecy wrote: post #2

Something I've always thought about. Northern Canada we run our wood stoves for ~8 months a year. Temp on the surface of the stove is 200C to 300C. Outside is -20C to -40C. Let's say an average of 200C temp delta across the TEC. Throw a radiator on the outside of the cabin, use coolant with a tiny pump to circulate. How much power am I going to generate with a square foot (or two) of TECs strapped to the wood stove,…

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…

> I do not consider burning wood to be sustainable

You can't really make such a broad statement. Sure, burning wood isn't a sustainable solution for everyone everywhere, but there's plenty of situations where it's the least-worse option for heating. My parents heat their house with wood they gather from their property which mostly falls naturally. It's impractical to do anything else with it.

Perhaps they could let it decompose - releasing approximately the same amount of carbon it releases in burning - but while that might benefit the local ecosystem marginally, it would also mean they were heating their house with fossil fuels instead.

Re: Thermoelectric heating stands at the brink of commercialization

#90

Post by leoedin »

Scoundreller wrote: post #33
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.

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%…

The problem is that heat pumps exist, so resistive heating is never the best option.

An aluminium smelting at home heating solution would have a maximum CoP of 2 (as you're reducing the energy usage of the smelter by the same amount). A heat pump could easily have a CoP of 3 or 4.

Post reply on HN