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

Staying cool without refrigerants: Next-generation Peltier cooling

news.samsung.com

Post reply on HN
Print view View original

71–80 of 329 posts

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

#71

Post by rcxdude »

madaxe_again wrote: post #67
dayjah wrote: post #18

I worked on a scientific instrument a while ago, it had a Peltier heater on it to raise the sample to 60c from whatever residual environment temp was (approx. 20c in a lab). It was pretty amazing to see my old overclocking cooling solution come back around and be used in my professional career some 20+ years later

And they couldn’t use a 100% efficient resistive element because…?

The TEC is more than 100% 'efficient' - you get more heat out than power you put in. Though I would guess it's mainly there to get heat control that can span above, around, and slightly below ambient.

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

#72

Post by majormajor »

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.

New appliances are far better than old ones here. Especially old ones that (I assume) haven't been maintained and so are working far harder than they used to. I've lived in places with old ones that were fine and old ones that were awful, both. I've had much more consistently good results in places with newer ones.

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

#73

Post by rcxdude »

BearOso wrote: post #8

AI has literally nothing to do with this. Why do they feel the need to sprinkle the phrase everywhere? AI inverter/compressor? Come on, have some sense of shame, please.

It's the name of the game, alas. In the area I work in, I've seen many companies get many multiples of the investment we've gotten because it's "quantum", even though they're trying to do the same thing we're doing and doing less well at it.

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

#74

Post by elzbardico »

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…

The time it stays above 4C unless you're opening the door of your refrigerator all the fucking time is mostly negligible in terms of the difference it will make for bacterial growth.

The foodstuff itself is loaded with water, it won't have an excursion dangerously above 4C just because you opened the door and the air temperature raised a few degrees.

If you are really worried about it (you shouldn't), and you don't keep your refrigerator full, add a few water bottles for thermal mass.

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

#75

Post by icehawk »

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…

The COP generally varies with Delta-T, a compressor-based heat pump's isn't any different. An AC unit is more efficient when it is cooler outside.

That said, 1.5C is tiny.

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

#76

Post by s0rce »

madaxe_again wrote: post #67
dayjah wrote: post #18

I worked on a scientific instrument a while ago, it had a Peltier heater on it to raise the sample to 60c from whatever residual environment temp was (approx. 20c in a lab). It was pretty amazing to see my old overclocking cooling solution come back around and be used in my professional career some 20+ years later

And they couldn’t use a 100% efficient resistive element because…?

typically only used if you need to stabilize the temp very close to room temperature or cool it below, unusual choice otherwise compared to a heater.

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

#77

Post by binarymax »

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…

For anyone wondering (like me) what COP is in this context, it’s Coefficient of Performance: https://en.m.wikipedia.org/wiki/Coefficient_of_performance

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

#78

Post by mousethatroared »

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…

COP has to be compared at the same delta T. The COP of a loss less refrigerator is infinite at Delta T = 0

And you dont get to stack Peltiers to increase COP, only to increase delta T.

Still, Peltiers are super cool and I have some ideas for their use od they get slightly better. Advances are super welcome.

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

#79

Post by elzbardico »

Tistron wrote: post #16

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

Move it outside a cabinet, let it free stand. I found out that my nice kitchen niche for the refrigerator acted like a nice resonance chamber for the frequencies the compressor generated.

I can barely hear it now.

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

#80

Post by dangus »

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…

If you buy something good like a Sub-Zero it will stay within 1 degree of the set point.
Post reply on HN