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

61–70 of 329 posts

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

#61

Post by rcxdude »

WarOnPrivacy wrote: post #2

I used peltier coolers on K6 processors 1M computer years ago. They worked great and lasted about as long as the PCs did. Not long after I bought mine, they disappeared from cooler offerings. I've wondered what became of the tech.

TDP went up. TECs are extremely inefficient, and have limits on how much heat they can pump in a given area anyway. a 10W chip, you can maybe get away with, and it might be a meaningful improvement compared to the other cooling tech available at the time, if you don't mind the power usage. with a 100W chip, you have no chance.

(You can see a demo here where LTT try it, and they, after dumping 500W into the cooler, can get the CPU to a vaguely reasonable temperature, until they actually load it up: https://www.youtube.com/watch?v=sWrqyQWfhrs)

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

#63

Post by savrajsingh »

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.

Because it works wonders on non-technical people

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

#64

Post by userbinator »

bob1029 wrote: post #55
esseph wrote: post #46

Earlier quoted context omitted.

You can hear your refrigerator???

The latest wave of appliances is really fucking loud for some reason. I think they're using different kinds of motor windings, bearings, insulation, etc. it's not related to the refrigerant or other system parameters. I've had older r600a fridges that were dead silent compared to anything sitting in a Best Buy showroom right now.

Likely high speed compressors --- the oldest hermetic systems used an induction motor running at 1800 RPM, then later they went to 3600 RPM, and now they're running on a VFD that possibly goes much faster. By making it pump faster, they can use a smaller compressor and reduce costs, at the expense of longevity and noise.

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

#65

Post by rcxdude »

wtallis wrote: post #23
numpad0 wrote: post #21

Earlier quoted context omitted.

There are no inherent max temperature deltas for Peltiers, just coefficient of performance, or watts moved per watts wasted, is atrociously low compared to just about everything else.

Peltier coolers have non-zero thermal conductivity and are pretty thin. At some point, heat leakage from the hot side to the cool side catches up to the rate of heat removal the cooler is capable of. What that point is will vary between devices, so there's no single or fundamental limit.

You can also stack them, but you need ever-increasing areas of TEC and corresponding power consumption. I think a triple-stack is sometimes practical if you want to get something to well below ambient and it doesn't really generate much heat itself (and you don't really want to use a traditional cooler due to size or vibration or something similar)

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

#66

Post by madaxe_again »

bob1029 wrote: post #55
esseph wrote: post #46

Earlier quoted context omitted.

You can hear your refrigerator???

The latest wave of appliances is really fucking loud for some reason. I think they're using different kinds of motor windings, bearings, insulation, etc. it's not related to the refrigerant or other system parameters. I've had older r600a fridges that were dead silent compared to anything sitting in a Best Buy showroom right now.

They use lighter lubricant oils than were historically used, which allows more vibration. It’s also why compressors burn out far more quickly than they used to.

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

#67

Post by madaxe_again »

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…?

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

#68

Post by obfuscator »

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…

Why should that be dangerous? I have never heard that.

I have always had my fridge at 8°C and never had something dangerous happen to me. I have never come across fridges that were way cooler, apart from fridges of friends in Canada and the US. What's the reasoning?

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

#69

Post by rcxdude »

closewith wrote: post #15
szvsw wrote: post #13

Earlier quoted context omitted.

FWIW, in a typical apartment or single-family home, refrigeration uses a fraction of the energy that space cooling (also via a refrigeration/vapor compression cycle) requires on a warm day (and probably year round too unless in very mild climates). The psychrometric chart path is different so there are of course differences in the amount of energy required for the sensible and latent components, but the real differen…

Definitely not the volume of air. The thermal mass of air is tiny. The difference is in the thermal mass of the building and the surface area exposed to the sun.

Also the area that needs insulating, and in the extremes the amount of air that needs to be exchanged with the outside to make the house livable, and the heat generated by the people living in it (stick a 100W lightbulb in a fridge and see how cold it can get).

The insulation is actually solvable, and for heating can basically remove the power requirements: a house heated and using heat exchange on air leaving vs entering can be heated a lot just by having people inside it, let alone the other energy they use for other purposes. It's just more expensive to build this way, and with cheap energy it can a long time to pay back. Cooling you can't push down past the heat generated inside the house divided by the COP of your cooler, though.

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

#70

Post by userbinator »

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.

It's worth noting that the very earliest electric refrigerators had a separate condensing unit outside; see this interesting 1920s Frigidaire training video for an example of what that was like: https://www.youtube.com/watch?v=W-t7DqOAMME

There were also centralised systems for apartments where one condensing unit supplied many evaporators in the refrigerator in each suite.

Post reply on HN