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Staying cool without refrigerants: Next-generation Peltier cooling

news.samsung.com

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Re: Staying cool without refrigerants: Next-generation Peltier cooling

#41

Post by sunshine-o »

nine_k wrote: post #19
cosmotic wrote: post #9

Earlier quoted context omitted.

The article says they have made peltiers 75% more efficient than existing ones.

OK, a typical Peltier device has 3.5% coefficient of performance, that is, it produces 35 W of cooling per 1 kW consumed. Fine, let's expect that the new tech doubles the efficiency, to 7%. Still, to my mind, pretty wasteful, on par with a steam railway engine. A Peltier element is good in cases where you can afford a large heat removal device, but need precise temperature control and no moving parts. For a home frid…

While Peltier cooling have low efficiency wouldn't it be ideal in some cases like:

- energy source is solar, DC already and abundant.

- cold climate so the fridge can contribute to heating the room

Anyway good to know those small electric cooler with Peltier effect must be consuming a lot electricity.

Re: Staying cool without refrigerants: Next-generation Peltier cooling

#42

Post by javiramos »

mort96 wrote: post #28
bluGill wrote: post #17

Earlier quoted context omitted.

They claim 75% better. I doubt this is better than compressors in general but they seem to be going for a niche where a high power compressor does the high load part but when only a litte cooling is needed the compressor is now very inefficient and so the peltier is better. Normal fridges just let the temperature have a wider swing which is good enough for most needs.

> Normal fridges just let the temperature have a wider swing which is good enough for most needs. These wide swings annoy me. You hear that you shouldn't let your fridge go above 4°C, because that's dangerous. And you obviously don't want your fridge to go below 0°C. But finding a setting where the hottest part of the fridge doesn't go above 4°C (or even 5°C or 6°C) during the hottest part of the cycle and the coldes…

You should buy a fridge with a fan in the cooling chamber. My Samsung fridge has a nice fan and associated ducting to circulate air and keep temperatures ~uniform.

Re: Staying cool without refrigerants: Next-generation Peltier cooling

#44

Post by HPsquared »

fghorow wrote: post #27

For those worried about tiny COPs from these gizmos, trawling through the actual paper -- as well as the PR from JHU APL -- in this HN post [1] shows claims of COPs of ~15 for Delta Ts of 1.3°C. A compressor based cooler gets a COP of about 4 in the real world. I'm pretty sure this is an apples to oranges comparison to an expert (I am not one of those) but a factor of 3+ increase in COP is fairly noteworthy -- if it…

What about a ΔT of say 20°C? I'd reckon most refrigerators and air conditioners are around there (temp difference of refrigerant between evaporator and condenser).

Stacking a bunch of these Peltiers to give more temperature difference would give a pretty low CoP. Say, for a 13°C temperature difference you'd have to stack 10 of them and use 10x the power. It's even worse actually as the hotter ones have to also pump the waste heat from the cooler ones.

Re: Staying cool without refrigerants: Next-generation Peltier cooling

#47

Post by toomuchtodo »

bob1029 wrote: post #29
Tistron wrote: post #16

What I want is a silent refrigerator, will this bring that? pray

I've been thinking about what it would look like to convert my GE fridge into a minisplit (i.e., move the compressor, condensing coil & fan outside). You can buy R600a on Amazon right now. One $60 can will charge the system ~5 times.

https://patents.google.com/patent/US20120192586A1/en

(abandoned)

Re: Staying cool without refrigerants: Next-generation Peltier cooling

#48

Post by MobiusHorizons »

fghorow wrote: post #27

For those worried about tiny COPs from these gizmos, trawling through the actual paper -- as well as the PR from JHU APL -- in this HN post [1] shows claims of COPs of ~15 for Delta Ts of 1.3°C. A compressor based cooler gets a COP of about 4 in the real world. I'm pretty sure this is an apples to oranges comparison to an expert (I am not one of those) but a factor of 3+ increase in COP is fairly noteworthy -- if it…

I believe the “apples to oranges” is the temperature gradient. AC units would routinely manage 15-20c and are rated for more than that. And some freezers manage up to 50c. The greater the gradient the worse the efficiency in general.

Re: Staying cool without refrigerants: Next-generation Peltier cooling

#49

Post by storus »

iLoveOncall wrote: post #35
NuclearPM wrote: post #33

Earlier quoted context omitted.

Why?

Not OP but it's a massive nuisance if you live in a studio. People don't realize how noisy a fridge is until there's one in the room that they sleep in.

Just today I ordered a 32dB Liebherr; the previous one had 35dB and could be heard all around the studio (I measured the noise using a dedicated sound meter).

Re: Staying cool without refrigerants: Next-generation Peltier cooling

#50

Post by koakuma-chan »

TealMyEal wrote: post #43
1oooqooq wrote: post #37

AI compressor. It's full on clown world.

What's even AI about it?

Much like a hybrid vehicle, this system intelligently switches between the two cooling methods depending on what best suits the situation.
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