
'Reverse microwave oven' quickly cools drink cans - tartoran
https://www.bbc.com/news/video_and_audio/headlines/51028494/ces-2020-juno-reverse-microwave-oven-cools-drinks-in-seconds
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gus_massa
Let's do the math:

Let's assume they use a can of soda of 350ml (12oz). In the video they say
it's "almost too hot to touch", let's say 60°C (140°F) and it cools to
refrigerator temperature, let's say 5°C (41°F), so it's a 55°C difference. We
can assume a specific heat of 1cal/g°C and a density of 1g/ml (metric units
are nice). So they have to extract 19250calories. (They need to extract some
calories from the can, but let's assume it's a small number.)

The 19250 calories are 80500J. They extract them in 90 seconds in the video,
so they have in average 895W.

They use between 100W and 200W of electricity, let's use 200W. So the
efficiency is about 4.5. In a air conditioner the usual efficiency is between
10 and 20, but it's a big device with a noisy heat exchanger. In a Peltier
device the efficiency is approximately .05. The efficiency changes a lot with
the temperature difference in both cases.

So, it doesn't seam to be theoretically impossible, but it looks too good to
be true. The only way I think this may work if it has a big chunk of ice
inside as a heat sink, so it can cool a few cans in 90 seconds, but it needs
like half an hour per can to regenerate the ice using a Peltier device.

> [...] _and it says fizzy drinks won 't spray in your face after a spin in
> Juno._

Nah.

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slater
I wonder what the difference between that and those rapid chillers is, e.g.
[https://www.amazon.com/Cooper-Cooler-Beverage-Chiller-
Silver...](https://www.amazon.com/Cooper-Cooler-Beverage-Chiller-
Silver/dp/B0000U3CIW/)

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mytailorisrich
They say that their prototype does not need an external source of cold and is
purely electric, so I'm thinking it might be using something like the Peltier
effect to generate cold. Apart from that they do look superficially similar.

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duelingjello
So is it sonic, cryogenic or something else (either fraudulent or real)?

