absorption refrigerator

I know I'm just dreaming, but has anyone tried making an absorption refrigerator? I've been thinking of making a walk in freezer that uses heat to cool, but not very knowledgeable about such stuff. Just wondering if I'm the only one.

Tim Day wrote:…making a walk in freezer that uses heat to cool, but not very knowledgeable about such stuff. Just wondering if I'm the only one.

Ever since reading Mosquito Coast, which by the way I consider propoganda to keep people afraid of trying what the protagonist tried, I really wanted such a device! Alas, simple tasks kept me too busy to try....I am really hoping this thread gets the attention of someone who has done it.....there are things called cool balls which are no longer in production....but I want the kind which can be built not bought!

I think if I can learn to build it, if there are any problems I would know how to fix them. I've read of the original ammonia refrigerators and wonder if I could use anhydrous ammonia to get started.  

I have wondered about them, but did not get very far in my thoughts.

I think they could be built, they had hockey rinks built using ammonia from 100 years ago, so if it could be done then, it should be able to be done DIY. I am not sure I would get into anhydrous ammonia though, farmers who have been sprayed by that crap have been blinded for life. It is nothing to mess with, but I am not your babysitter, just know the dangers and do as you see fit.

In my case I ended up looking into buying a refrigerator to taking the engineering learning curve out, and in the end it was much less costly to just run an electric one, or get enough electricity in an off-grid situation to run an electric one. The propane consumption was fairly substantial.

I think going back to blocks of ice might hold more promise for low cost refrigeration. I live in Maine so it gets plenty cold here. I would think we have the technology now to make ice in the winter, and then retard the ice melt through most of the summer, and then refreeze the water in the winter again. I think something a bit better then cutting and hauling blocks of ice could be done.

Tim Day wrote: I could use anhydrous ammonia to get started.  

Yes you can but it is very poisonous, on the dhs watch list, and your system must have no room for error.

Here's the basic idea
https://en.m.wikipedia.org/wiki/Absorption_refrigerator
1-Evaporation: A liquid refrigerant evaporates in a low partial pressure environment, thus extracting heat from its surroundings (e.g. the refrigerator's compartment). Because of the low partial pressure, the temperature needed for evaporation is also low.

2-Absorption: The now gaseous refrigerant is absorbed by another liquid (e.g. a salt solution).

3-Regeneration: The refrigerant-saturated liquid is
heated, causing the refrigerant to evaporate out. The hot gaseous refrigerant passes through a heat exchanger, transferring its heat outside the system (such as to surrounding ambient-temperature air), and condenses. The condensed (liquid) refrigerant supplies the evaporation phase.

Now that you've pressed the point, I do remember someone creating a solar absorption frig....let me see if I saved it in my data files tonight.

Okay here we go, I did do some research and found these a while ago.

Here's a link to multiple tests:
http://www.appropedia.org/The_Design_and_Development_of_a_Solar_Powered_Refrigerator


...I swore I found one that did not require any pumps or fans or compressors...the heat was released overnight and the sun drove the process all over again during the day....


....sorry, going off line for awhile.....hope to come back and find you've put together a system!

connor burke wrote:Im curious about the apliation of using a solar heated chiminy to heat the lower bit while drawing moisture of of the fridge like a yakital thing. By creating a lower air pressure it could cool the food and such via evaporation easier. Yall have any thoughts

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...draw me a simple picture so I can understand (paint if windows, gimp if linux  who knows what mac does any more)

connor burke wrote:

Orin Raichart wrote:

connor burke wrote:Im curious about the application of using a solar heated chimney to heat the lower bit while drawing moisture of of the fridge like a yakital thing. By creating a lower air pressure it could cool the food and such via evaporation easier. Yall have any thoughts

\\
...draw me a simple picture so I can understand (paint if windows, gimp if linux  who knows what mac does any more)

i posted the thing, do you have any thoughts? i figured a absorption fridge would be good for supplementing the shoddy evaporation

My approach is to put all the cold in one area and all the hot in another area with great insulation between.  Rather pointing out the issues with your diagram, I encourage you to build a model or just one of these full size devices. In this manner, you will learn the difference between theory and real time heat energy (if you pay attention). Then make changes to your system or model so you can notice what variables produce what so you can understand how.  Good luck.

Possibly a zeer pot or similar?  India and other areas use smaller versions, but much larger ones are possible.  This is also on my experimental 'to do' list.

https://www.youtube.com/watch?v=enOjVc-kN7Q


If you want much larger, as for a community, perhaps a yakhchal?

http://www.historyofrefrigeration.com/refrigeration-history/yakhchal-ancient-refrigerator/

Is this the process they use for propane camper refrigerators?
I think they are full of ammonia.

Don't know if it is on topic but I wondered often if the lpg in cars (propane boils at -38 degrees celsius) couldn't be used to replace the compressor for the aircon. Normally the car's watercooling system absorbs this cold what is generated by leading the gas into the evaporator...

Also, i read somewhere a long time ago that some university student in india replaced the coolant of a fridge with propane, and it worked better than the original coolant. The safety was no issue as the amount was so low that it would never be a threat.

Interesting stuff../

Lots of good ideas to go over, thanks for all the input.

> propane refrigerant

Works very well. But it burns something fierce so it's not found in commercial products, especially vehicle products. They ever catch you with propane refrigerant in any kind of vehicle accident and you're looking at a world of hurt. Your call whether you feel it's worth the risk otherwise. Also, many systems need lubricant in the refrigerant to keep the mechanicals happy and there's a few other components that need to be changed/adjusted - takes a bit of engineering to get the system right and by the time it works (sorta) it might have cost more in just time than it's worth.

Not as bad a that ammonia stuff, though. When I was about 10, I was messing around my father's den in the basement and decided to plug in the old refrigerator from the 1930's that he used for a filing cabinet. Ran nice, purred right along, but all a sudden I started having trouble breathing. Ripped that cord out of the wall and RAN out of there. Scared the beJesus out of myself.


Rufus