being colorblind, specifically deuteranomaly, it worked, but i do not see the blue green, i see the weird off green i normally do and then basically brown. i would imagine complete red-green would actually impact it
Staying cool without refrigerants: Next-generation Peltier cooling
91–100 of 329 posts
Re: Staying cool without refrigerants: Next-generation Peltier cooling
#92Earlier quoted context omitted.
> 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?
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Re: Staying cool without refrigerants: Next-generation Peltier cooling
#93Sounds like they’re using much thinner and thus more efficient bonding on each end of the Peltier device?
75% gains off that seems impressive. Must be something really fancy - thinking of a heat sink just using better therm paste barely moves the needle
Re: Staying cool without refrigerants: Next-generation Peltier cooling
#94I thought Peltiers can't lower the temperature by more than 40 degrees F, in practice less than that. This is not cold enough for a refrigerator on a warm day.
That's a question of mass and power.
Re: Staying cool without refrigerants: Next-generation Peltier cooling
#95I 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…?
Because Peltiers are, at their most inefficient 100% efficient?
At a reasonable delta T you can get 200% efficiencies.
Re: Staying cool without refrigerants: Next-generation Peltier cooling
#96I 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.
They weren't worth it. Their only advantage is they can cool below room T, but then you have condensation problems.
Re: Staying cool without refrigerants: Next-generation Peltier cooling
#97Re: Staying cool without refrigerants: Next-generation Peltier cooling
#98> Bespoke AI Hybrid Refrigerator
Come the fuck on.
Re: Staying cool without refrigerants: Next-generation Peltier cooling
#99What I want is a silent refrigerator, will this bring that? pray
You can hear your refrigerator???
You can't? Refrigerators have always made a noticeable background noise as they cycle on and off.
The advantage of the newer variable speed scroll compressors in some high end fridges is that they can run continuously at a slower speed.
Re: Staying cool without refrigerants: Next-generation Peltier cooling
#100Earlier quoted context omitted.
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…
"that is, it produces 35 W of cooling per 1 kW consumed." No, they don't. First, without defining a delta T, efficiency is meaningless (unless its a Carnot cycle). Second, the efficiency is (depending on op. point) higher than 100%. See [1]. You can pump 20 W of thermal power with 2 A @ 4 V = 8 W 20 W of cooling for 8 W of work, or an efficiency of > 200%. This is common to all refrigeration cycles, and frankly for a…
Oh, indeed I was wrong; COP of Peltier elements is much higher than I had gleaned from online charts, not the order of 0.03 (3%) but can easily reach values above 1.0 (100%) and be e.g. 0.5 (50%) at ΔT = 30C, enough for a home fridge.
Still a bit far from compressor-based designs, but not negligible, and almost doubling the efficiency is indeed a serious advance.