The Einstein refrigerator.
 

Einstein refrigerator.


Few people know about an joint designed invention that Albert Einstein helped design and its impact for off grid homes and the RV industry today.

The Einstein refrigerator is an absorption-type refrigerator which has no moving parts and requires only a heat source to operate. It was jointly invented in 1926 by Albert Einstein and his former student Leó Szilárd and patented in the US on November 11, 1930 (U.S. Patent 1,781,541

From 1926 until 1933 Einstein and Szilárd collaborated on ways to improve home refrigeration technology. The two were motivated by contemporary newspaper reports of a Berlin family who had been killed when a seal in their refrigerator broke and leaked toxic fumes into their home. Einstein and Szilard proposed that a device without moving parts would eliminate the potential for seal failure, and explored practical applications for different refrigeration cycles. 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 eventually being granted 45 patents in their names for three different models.

The refrigerator was not immediately put into commercial production, the most promising of their patents being quickly bought up by the Swedish company AB Electrolux to protect its refrigeration technology from competition. A few demonstration units were constructed from other patents.

The invention of Freon in 1930 rendered the vapour compression process the standard for refrigeration; however, concerns about the effects of Freon as an ozone depleting agent may cause a revaluation of Einstein and Szilard's design. - Wikipedia



AB Electrolux is now renamed Dometic Inc. the leading manufactor of gas refrigerators for the RV industry.

The absorption cycle refrigerator has been designed from handy portable units the size of chest coolers to double door freezer fridge for modern homes.

An interesting feature of these refrigerators it they will operate on a variety of fuel sources, LP gas, natural gas, 120 VAC and 12 VDC power.

I highly recommend these units, I own a couple of the units, a Norcold double door LP/120 vac unit and a portable Dometic mini freezer for fishing trips.



Of course if you own an RV, odds have it, you also own an Einstein refrigerator.

Re: The Einstein refrigerator.
 

QWAK,bsdetector,I would be interisted in learning more how the refrigeration cicle works.

I took a 1902 Oak Ice box and turned it in to a modern freezer refrigerator many years ago. In moving a freeon line was damaged and NOW it is almost imposable to get R12 freeon to put it back on line.

the DUCK

Re: The Einstein refrigerator.
 

There is something called Redtek that the mechanics use to recharge auto air conditions on the cheap. It is supposed to be able to replace R12 and R134. It worked great on my truck's AC, but I don't know how good it is for a freezer.

Re: The Einstein refrigerator.
 

I think that a dilute ammonia in water solution is used in commercial absorbstion refrigerators. another potential refrigerant that could be used, and is cheep enough: propane.
Guy I know wants to run a closed system heat engine with ammonia at 45 PSI driving a pelton wheel, plan is to make efficient use of a 60 degree temperature differential, primary heat source solar with the potential for passive farm waste decomposition ( translation: compost heap) to augment in winter.

Re: The Einstein refrigerator.
 

I bought on of those ThermoElectric rigs for my truck, a real disappointment, lucky to get cool enough to keep a candy bar from melting.

I heard they did okay in an air conditioned room but not for outside real world hot climates. I use it as an extra glove box now.

The TE rig I bought draws 60 watts continuous, the little absorption refrigerator I replaced it with draws the same (on dc power) but actually makes ice. At the camp site I just run it on little disposable propane bottles instead of draining the car battery.

Re: The Einstein refrigerator.
 

Another type of primitive refrigeration, you can run it with a wood fire. The Crosley Icy Ball. Info in the links below.
Information here
http://lionheart.net/fridge/descript.htm
Pictures and more info.
http://blog.makezine.com/archive/2006/10/crosley_icyball.html

Re: The Einstein refrigerator.
 

Mine's a Dometic, from an old tent trailer. Cheap (ruined) tent trailers can often be bought cheaper than a new 3-way fridge, and you can resell the stripped frame as a box trailer, usually for more than you paid out initially (if you're any good at all with a welder).

Re: The Einstein refrigerator.
 

Does anyone have plans I can work from to build an Einstien refridgerator? I'm pretty handy at welding a plumbing, but I need something to work from that's better than the 2" x 3" picture floating around the internet.

Re: The Einstein refrigerator.
 

Will the Service manual do?

Re: The Einstein refrigerator.
 

Anhydrous ammonia is deadly in small quantities. Unless you're a certified refrigeration mechanic (or a meth dope cooker with a death wish) I'd leave it alone.

http://www.gas-refrigerators.com/images/absorption.gif

Re: The Einstein refrigerator.
 

QWAK,I have an anteaque refrig I hauled down here orignaly ran on natural gas but seemed to work fine on propane. It usees Anhydrous ammonia and makes Ice. It was big but only small inside because of so much insolation.

Thing is built like a TANK.

I am wondering if it is the same thing?

I have it in my work shop and use it for storing my welding rod and other welding stuff.

The casting that holds the burner head is cracked making adjustment a hastle but other than that it is as good today as when it was manufactured long befor they started using plastic.

Built to LAST and about as simple as posable. I dbout any modern frig will last 1/4 as long.

the DUCK

Re: The Einstein refrigerator.
 

Actually, what you have left un-said is that ammonia is VERY UNPLEASANT in small quantities, unpleasant to the point that one is strongly compelled to vacate premises when even VERY small concentrations occur. It is actually hard to be around dangerous concentrations of ammonia because the normal reflex is to flee.
I know an older gentleman who had a very large ( as in fish packing plant) industrial ammonia refrigeration system catastrophically fail, and dumped a VERY large quantity of liquid ammonia on him, way indoors. eyewitnesses claimed that as he made it out of the burning building he was blowing liquid ammonia out his mouth and nose. He was hospitalized for some time, and had bad chemical burns, but he is up and around now. he walks, can handle stairs, but his lungs are marginal. there were several dozen employees present, but this guy was the only one hospitalized.
As the cloud from this particular explosion and fire was headed toward my house ten miles distant, I had my family pack up and relocate in a bit of a hurry. after about 18 hours or so the fire burned it self out, and the dozen or so stored ammonia cylinders blew up and vented without harming anyone.
Any way that was july 1999, and the end of Icicle Seafoods fish plant in Homer AK.

Re: The Einstein refrigerator.
 

That's because there's no compressor, moving parts.

It heats the ammonia solution and moves it like a coffee percolator.

My grandfather had a gas fridge, a Servel. Bought in 1940, went to estate auction in 1982.

It still ran.

Re: The Einstein refrigerator.
 

I don't mean to hijack your thread too much but you folks seem to be knowledgeable on an issue related to one I am thinking about. I would like to know how to build a workable ice house or ice cellar. Any favorite sources of info on such a thing?

Re: The Einstein refrigerator.
 

I have two servels sittin up the road a piece in a canyon , they were operable when I replaced them (also from the 40s)with a low voltage dc "Sunfrost" refridgerator which we never really liked that much. We left the Sunfrost in our old unocupied house (used for storage now) and are currently using a standard 110volt ac fridge that is powered as is the rest of our house from a 48 volt dc photovoltaic array converted to 110vac via a trace sine wave inverter.....and the first chance I get to replace this mainstream hunk a crap I will, although it has some nice features it uses to much energy for my taste.

The improvements would be going back in time and borrowing from the past by putting the compressor back on top so it can dissapate heat and keep the coil cleaner, then build it over square instead of like a shallow display case that lets the cold roll out when opened, and then of course it needs to be super insulated like a Sunfrost, BTW Sunfrost puts there dc compressor on top but there was no air circulation in it and there was always condensation on the bottom of the interior , we did overcome lack of air movement with a little battery powered fan.....I dunno, it just wasn't user friendly. If any major manufacturer opted to consider the need for efficent refridgeration ,and build one , there would be NO power shortages , refridgeration is by far the biggest power hog .

Re: The Einstein refrigerator.
 

Yes, the refrigerator is a huge consumer of electric power, I like my Norcold for power failures, it automatically switches over to LP gas during a power outage but it uses 12 volts dc for the controls so my battery bank better be charged up ...

The prices of a small double door fridge/freezer unit like my 8 cu.ft, is ridiculous, to buy new (about $1600) so its best to salvage a good old used RV fridge.

Even the little portable ones cost about $500, so I bought one that was slightly abused with a good cooling unit and rebuilt the controls, put new door seals in and a new burner. Cost me about $75 when all said and done.

Re: The Einstein refrigerator.
 

Who told you about my meth lab?

Ok, assuming I'm not looking to die yet... are there any other (simple) ways to build a fridge powered by a heat source?

Re: The Einstein refrigerator.
 

A zeolite refrigerator could be constructed using water as the refrigerant and zeolite as the absorber.

You'll need some form of manual vacuum pump to get it started and a heat source to recharge (dry out) the zeolite.

Good question, don't know for sure.


All I know is the thermoelectric rigs sold at Wally World suck a lot of power for crappy cooling.

My little Dometic cooler makes ice for the same wattage input and if needed I can run it on candle power !



.

Re: The Einstein refrigerator.
 

Light a fire to make things cold. Intersting.
Amish use these in natural gas, propane and kerosene versions.
Kerosene fridges operate very very cheaply.

http://www.howstuffworks.com/framed....bsorption.html

http://www.lehmans.com/shopping/prod...iProductID=557

Re: The Einstein refrigerator.
 

http://www.energy-concepts.com/isaac.html

you can take it a step further and use the sun as a heat source

Re: The Einstein refrigerator.
 

When I am not hanging around GIM I make Trailers or Caravans as they are called in Australia.

As you can imagine the climate can get very hot here...45 degrees celcius is common.

Anyway the Electrolux / Dometic Gas Absorbtion fridge is the best available and works quite well.

They will keep your beers sufficiently chilled but you wont be able to throw the backend of a moose in there sorry folks. :)

The Waeco, Engel and Vitrifrigo also do the job very well.

No amount of welding will make one of these units as they are finely engineered products and they use toxic chemicals to make the process work.

Re: The Einstein refrigerator.
 

When heat pump technology became more efficient than COP = 5 or better, self running (self powering) units became possible using environmental temperature gradients.

The usual source of one side (heat or cold as necessary) is a ground loop.

Total equipment cost is the prohibitive consideration, but it is possible to provide heat, electricity, and/or air conditioning with no electrical input other than available from environmental temperature gradients.

I believe carbon dioxide gas has also been used as the working media, however the commercial refrigerants are probably better choices.

You will need a trained engineer familiar with this science to design the system - no commercial model is available. Expect cost to be ~$20K or more.

Carver

Re: The Einstein refrigerator.
 

As a holder of a Universal Reefer license, I feel compelled to say this loudly and clearly, but not with insult:
PLEASE BE EXTREMELY CAREFUL WITH AMMOIA AND PROPANE. When you compress a gas, it heats up... VERY hot. Not so good an idea with with propane. Ammonia is also flammable in addition to being HIGHLY toxic to humans. Commercial units are built and engineered with cartain pipe thickenesses and materials and orifaces to maintain certain pressures and temperatures in certain parts of the reefer in certain stages of the refridgeration cycle.
Other notes: It sounds like he is building a Sterling engine with ammonia...

Re: The Einstein refrigerator.
 

Let me hijack the thread even further and tell you about a friends freezer,this thing is amazing! They also sell refrigerators in the same chest style.When you have sunshine 150 watts of panels will power this no sweat.Comes in 12 and 24 volt DC models.

Link To MANUFACTURER INFO

Here is my review of a sundanzer freezer in use,not much to say.Plug it in and it works...


A Sundanzer 8.1 cubic foot freezer,uses 2 amps or the equivalent of 2, 27 watt CFL light bulbs,or 2 amps when running.

Set to zero degrees F. Runs about 6 hours a day (12 amp/hrs per day at 24 volts,also runs on 12 volts) with ambient temps about 48-68 degrees F.
AMAZING!!!

Costs about 1100 dollars delivered.

http://i34.photobucket.com/albums/d1...alameal141.jpg

http://i34.photobucket.com/albums/d1...alameal142.jpg

Re: The Einstein refrigerator.
 

Me too, I'll repair burners and controls, maybe invert a vapor locked unit but I won't mess with a flat fridge. Trash it or buy a new cooling unit.

Re: The Einstein refrigerator.
 

I almost hesitate to bring it up, but I've read of something I'll call the "Hawking" icebox. :wink:

I'm not a physicist, but the idea is that a perfect black-body will absorb or emit radiation perfectly. In this case, it is the emitting we're interested in. Note that a black object will emit radiation (we're interested in heat) into space. The greater the surface area, the greater the amount of heat than can be radiated. A common application of this is in your computer in the form of a heatsink.

So, we should be able to apply this same principle to building an old-fashioned icebox. The main body--the food storage area--is a well insulated area. Inside this storage space is an aluminum (copper is even better) grid, ideally painted black to best conduct heat. This grid is channeled through a conduit in the top of the box, where it opens up into an array of radiating fins, like that computer heatsink has, although much bigger. Every other part on the outside of the icebox is white or silvery to reflect as much inbound heat as possible.

Set it outside at night. The theory is that the heat of the water or food inside will be conducted to the outside and radiated into space. Simply placing the box outside at night should allow you to create blocks of ice overnight, which could then be used to cool food during the day.

Things to remember: That black-body is also a perfect absorber of radiation, so we want to make sure we move it inside before the sun comes up, or heat will be transmitted back into the icebox. There are ways to make the process more efficient, like using car antifreeze as a medium for moving that heat more efficiently from inside to outside. It should be possible for this circulation to be solely conducted based on a colder liquid being denser than the hot and circulating on its own, but it will do better with a small pump--but you need electricity for that. Maybe a small battery-operated one will suffice.

As I said, I've read about it, but I haven't heard from anyone who has actually built one--which should in no way indicate it hasn't been done.

Re: The Einstein refrigerator.
 

Interesting idea. At the very least, the radiator as it faces the sky is going to need to be covered in glass (transparent to IR) inside a vacuum. Otherwise your radiator is just going to be cooled to ambient temperature by convection and no further. There also may be issues on cloudy nights.

Re: The Einstein refrigerator.
 

UL, what you are describing is a heat-pump free energy machine. A Maxwell Demon if you will.

http://universe-review.ca/I01-09-demon.jpg

Something on the subject

and something more

http://www.vectorsite.net/tpecp_10.html

Re: The Einstein refrigerator.
 

Thanks for getting me to think a bit more about things.

I forgot that the atmosphere will re-radiate infrared back at the radiator. I suspect that for this reason, the radiator, even if in a vacuum with a lens that is transparent to IR radiation, will not get colder than ambient. I could be wrong.

If that chamber was several km tall (such that the radiator was free to radiate to space unblocked by an atmosphere re-radiating infrared at the radiator) and the sides were silvered, I think that would work and it wouldn't violate the second law of thermodynamics. You'd probably need several layers of silvering and vacuum at the side to keep the sides in the middle of what is effectively a cavity radiator from heating up.

Of course, we are dealing with something that would be ridiculously expensive and hence impractical.

On a small scale, obviously it is possible for something the same distance from the sun as the earth to be passively cooled to very small temperatures. Satellites can be. The same principles can be extended to the earth.

To get it to work on earth, you need to be able to radiate the heat back into space at night time without the atmosphere radiating it back at you. And in fact, if you are to go to the extent of having a channel outside the atmosphere, you can design this channel such that the sun never shines into the channel, but the channel provides a port for radiation to shine out into the rest of space. In this way you get around having to have a door that opens and closes.

I suspect the idea of shutting the door triggered your reference to the "Maxwell Demon" analogy, but I don't believe it applies to this case.

Of course, I suspect that due to reflection of IR by the atmosphere, such a device will be impractical, but I don't believe it's due to being a free energy machine.

Re: The Einstein refrigerator.
 

Re: The Einstein refrigerator.
 

One more thing, it appears that the maximum amount of radiative cooling that can be done in the atmosphere is 6 degrees in optimal conditions.

I suspect that in a vacuum this would be more because it would eliminate convective cooling. Which would be entirely impractical, but nevermind.

Re: The Einstein refrigerator.
 

Hmmm...too bad, Still, it would seem to have a few practical applications, even if making blocks of ice isn't one of them.