
Einstein Refrigerator - denzil_correa
https://en.wikipedia.org/wiki/Einstein_refrigerator
======
jmiskovic
This design is among many low-tech alternatives to modern appliances and
processes mentioned in book The Knowledge: How to Rebuild Civilization in the
Aftermath of a Cataclysm. It was not successful because of already established
industry of refrigerators that were good enough. The book is excellent.

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tinus_hn
According to the article the patents were bought by Electrolux. It could be
this was just to block this technology from being adopted.

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AstralStorm
No, it has been actually deployed and is commercially sold as heat recovery
chiller.

The problem is an much lower efficiency than compression refrigerators, some
of which could be regained by tuning the liquids used in the system. That is
not a problem when you're working with waste heat though. (E.g. solar thermal,
recovery from solar concentrated, cogeneration, geothermal.) The other problem
is that it has to be perfectly leak checked or it does not work at all, where
in compression leakage just reduces efficiency - and there's much less piping
that has to be pressure sealed.

COP of maybe 1.3 for best designs is available, compared to say 5 of a top of
the line screw chiller, 7 of a rotary chiller and 3 of very good heat pump.
(Maybe COP could be pushed a bit higher with exotic liquids. But the economics
of this endeavor are suspect. Current top efficiency liquids are water-
ammonia/lithium bromide-water dual loop. It is not safe compared to HFCs.)

It starts making sense when the installation is building sized, because
maintenance is cheap compared to an electric chiller.

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gwbas1c
I thought this is how RV (propane) refrigerators work? Or, am I confusing this
with a different, but similar system?

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baybal2
You mean fridges that use propane as fuel or ones that use it as a freon?

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jhiesey
As a fuel. And yes, it's the same principle.

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Scoobert
There's a good write-up here: [https://www.wired.com/story/einsteins-little-
known-passion-p...](https://www.wired.com/story/einsteins-little-known-
passion-project-a-refrigerator/)

It's a bit conspiratorial to suggest this was technology bought and buried by
Big Air Conditioning

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0db532a0
It would be interesting to know the practicality of this fridge and its
efficiency in relation to more conventional fridges.

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mikestew
The practicality is answered by the fact that many/most recreational vehicles
you see going down the road will use a refrigerator like this. As for power
efficiency, in comparing compressor fridges to absorption, I think a well-
design compressor fridge will use less electricity (absorption fridges can use
an electric heater, too), but not by a huge margin. But if your efficiency
question is about how well it keeps things cool, ours will make ice cubes when
it's in the 80s F.

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hn_user2
The last time I researched this, absorption fridges when run on electric
resistance heating use on the order of 300% more energy.

But of course in the case of an RV where you are on a car battery but have a
large propane tank, they make sense in terms of energy storage.

With the more cost effective Lithium batteries the higher end RV coaches have
all eliminated the absorption fridges and gone with compressors and bigger
batteries.

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0db532a0
Are you saying that they run on a propane flame in the RV?

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jml7c5
Correct! Any heat source of sufficient temperature will work, but propane is
convenient. I recently took a ferry in Idaho; before loading, people in RVs
were told to turn off their refrigerator to reduce fire risk. Searching for
"absorption refrigerator diagram" (or checking out the wikipedia page) should
provide useful information.

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0db532a0
Thanks.

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abfan1127
I'm not sure, but RV refrigerators work the same way, by heating Ammonia (via
propane usually). because the heat source is typically propane, its great for
locations without electricity.

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timeattack
Looks like you're talking about
[https://en.wikipedia.org/wiki/Icyball](https://en.wikipedia.org/wiki/Icyball)

~~~
abfan1127
it says its used in RV applications, but I don't see how the described system
uses propane to heat a portion of the closed loop.

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DoreenMichele
If you are looking for post-apocalypse design options, or even practical
solutions for current real world problems to try to avert the apocalypse,
there is also a zeer, aka "pot in pot refrigerator."

[https://en.m.wikipedia.org/wiki/Pot-in-
pot_refrigerator](https://en.m.wikipedia.org/wiki/Pot-in-pot_refrigerator)

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mirimir
> ... requires only a heat source to operate.

Nope. It also requires a heat sink.

~~~
mirimir
Belated edit: See
[https://en.wikipedia.org/wiki/Einstein_refrigerator#/media/F...](https://en.wikipedia.org/wiki/Einstein_refrigerator#/media/File:Einstein_Refrigerator_pat1781541_clarified.jpg)

> ... Intermediate Condenser ... Cooling Water ...

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dredmorbius
NB / OT: I'm getting NET::ERR_CERT_AUTHORITY_INVALID for wikipedia.org
currently.

Update: Working with Wikipedia on this. They pushed a new set of certs earlier
today. There may be issues with some UAs. My old, stale Android (5.0.2) and
Chrome (76.0.3809.132) aren't happy with Wikipedia _or_ Globalsign's root test
URL:

[https://valid.r5.roots.globalsign.com/](https://valid.r5.roots.globalsign.com/)

(Also an ERR_CERT_AUTHORITY_INVALID)

I suspect a stale CA list somewhere.

~~~
dredmorbius
This has been resolved, working through Wikipedia:

 _We 've deployed a cross-chained intermediate back to the older R3 root now,
which we believe will fix this for you (and other such clients). It has a
small perf impact on all of the modern clients, but I think Android 5 isn't
quite old enough yet that we can just ignore its compatibility._

(Via email.)

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devnulloverflow
Is there an actual explanation of how the design fridge works?

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madengr
They received the equivalent of $10k for their patent. Doesn’t it cost about
$25k today to file a patent?

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SuoDuanDao
I imagine Einstein, given his first job, could file a lot of the paperwork
himself ;)

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mhb
_Einstein used the experience he had gained during his years at the Swiss
Patent Office to apply for valid patents for their inventions in several
countries. The two were eventually granted 45 patents in their names for three
different models._

