Introduction: Homemade Clay Refrigerator - BEING ECOFRIENDLY !

Picture of Homemade Clay Refrigerator - BEING ECOFRIENDLY !

Hi, I am Sahas Chitlange , aging 14 , from India . Here's my new innovation on fridge from clay. Its very easy and cheap to build and very cheap. In india the cost is about  Rs. 300 only. The project's principle is based on evaporation. you can take this system for camping where you need a fridge to keep your cokes cool. The materials required for making this easy fridge are:
1) Clay pots
2) some sand
3) water

For the first time to get the cooling effect you need to wait for 10-12 hrs. The thing you need to remember is adding water after a day.

Step 1: Chose Correct Pots

Picture of Chose Correct Pots

You need to chose correct size pots so that they go into each other easily. Prefer new ones because old ones have their pores blocked. This affects cooling.

Step 2: Adding Sand

Picture of Adding Sand

Add some sand in the base of the larger pot. You may close the pot holes. I did not.  You may also heat the sand strongly to kill the germs as in India you get the sand on roadsides!

Step 3: Insert the Smaller Pot

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Now insert the smaller pot in the larger one. Take care you may get your hands jammed during this process. I got once, Very painfull...
Also see that you have some gap left on the sides , you need to add sand there later.

Step 4: Add Sand to the Sides

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Carefully add sand on the sides of the pot. Avoid spilling it into the smaller pot , its very difficult to get that stuff out once spilled in ! Also add some water after you add sand.

Step 5: Cover It

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You can make a cover out of old pots as i did or simply cover it with a damp cloth.

Step 6: Enjoy Cooling

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Its the time to enjoy cooling.


rodolfo.masiero (author)2016-09-27

Ben fatto!

andriajithu (author)2015-09-08

Good idea... can try it at home.... Thank you...

jacobpv (author)2013-11-17

how long it will take to get the required low temperature???

ccooper-burke (author)jacobpv2015-07-09

That depends on the sizes of the jars, how cold the water was, when you dampened it, the ambient temperature, and the relative humidity. So, it would be difficult to give an accurate answer.

Cambenora (author)2015-05-04

Cool instructable (if you'll pardon the pun...)

In Australia in the 19th century there was a thing called a Coolgardie safe:


which was a refrigerator which used water evaporation as its cooling mechanism much in the same way as you have here. A different design, but the same principal.

Good work.

TrevorS3 (author)2015-03-09

So this stays outside? Should it be in the shade or out in the sun? If it is in sun then it will evaporate faster and cool better but will also need more evaporation to compensate for greater heat... I live in a smallish trailer and don't want to use propane to keep food cool and don't have it in the budget for a large solar panel.

I will try and rig up a drip irrigation emitter to drip over bowl part into sand and either use timer or get very low flow emitter and drill an overflow opening towards top.

Saakaar Barthwal (author)2014-12-08

wowwww cool it is just like mitticool

burnettis.1 (author)2014-10-05

very nice and more power to you for sharing your knowledge.

I live in Morocco, so it is good news for poor people and those with out electricity.

I will share your generous work.

snoopindaweb (author)2014-06-01

cOOl.! ~( : - } )=>=== ] Favorited. The vote don't seem to work.


coinegue (author)2014-05-31

Thank you Sahas for sharing that knowledge.
Great, this is very sustainable!
Once I saw a Berber fresh water keeper. It was made by metal, covered by fabric parts. The trick is to mantain it wet, adding water outside. The water evaporation gets it super fresh. And the guy who add it told it works really well with high temperatures. I also heard and read about this techniques used in the north of Africa.
I'm from Portugal. The old arabs left in our culture this ancient technique, made with clay, then straw, then some fabric parts covering all. I think the only inconvenient is the smell it gets after a while, needs to change all the cover.
I want to try this in the Azores, but there is very humid. I saw here that it might not work so well. I'm curious, but I believe that will be the same or better...
I like the design of yours, its very cool... The sand and how you configure inside is fantastic.

aebe (author)2013-12-13

Low tech is always good , even if it just sits in the back of your mind , waiting for a need. In areas of low humidity , you might find that ice (frost) is possible , just by using a northern exposure at night .

neelakantam aravindraj (author)2013-11-20

thanks.....for posting.......
i am from india......

jsolterbeck (author)2013-11-19

This is so cool thanks for posting! I will try it here in America! ;)

tekaka (author)2013-11-19

thanks Sahas, we have been working on this for a couple of years, next spring we will go for our tenth year without fridge here in hot andalucia. thanks for giving us, he world, this support in surviving. abrazo tkk

kidharris (author)2013-11-18

In addition the nay sayers for the use in high humidity regions are neglecting several other factors.

1. Insulation value & thermal mass of the pots, sand, and water slow down the heat up of the interior during the day.
2. Radiation to the night sky can cool down the pots at night.
3. Some water does evaporate regardless of the high humidity. If it did not then people in Florida could not mop their floors, clean their counter tops, or use clothes lines to dry their clothes. The "experts" talking about dry bulb & wet bulb temperature and evaporation are confusing air conditioning with refrigeration. Air conditioning has to do with cooling massive amounts of air to provide human comfort which is much different from keeping a few pounds of food from over heating. Human comfort involves how the human "feels" and reacts with its environment. Things like chill factor (how fast the water/sweat evaporates off the human body) are involved here. Meat on the other hand does not feel chill factor, however, it can dehydrate or rot, which is what we are trying to prevent or slow down with the pot system.

kidharris (author)kidharris2013-11-18

I forgot to thank the author for exposing more people to the concept that everything does not have to be high tech or expensive to work.

I do not think that this will catch on here in the USA because it requires effort and conscious daily thought to work, it is not automatic or convenient. However, I do hope that they will remember it, because it could save their life, or at least make it more comfortable, in the event that there is ever a long term breakdown in energy &and/or food supply in their area. I'm sure that the preppers will pick up on it.

kidharris (author)kidharris2013-11-18

Sorry, I'm so forgetful.

A possible improvement might be to have 2 lids. One black, possibly made of metal, to help with night time radiation to the night sky. The other white/silvered (reflective) and insulated for daytime use. You would have to be very conscientious about changing both lids while it is dark outside.

rkrishnan7 (author)2013-11-17

Great Instructable! Your instructions are brief but clear and illustrated well. You may want to add that the temperature difference that you get between the ambient outside and the inside of the pot depends a lot on the relative humidity in your region. The effectiveness is best in arid areas where the relative humidity is low. I recall that these worked well during the hot New Delhi summers, but were not too good during the Bombay monsoons :)

gn0stik (author)rkrishnan72013-11-18

The terra cotta should do a pretty good job at absorbing most ambient moisture, just keep it out of the rain. As long as it is well sealed, and covered, it should be fine.

rimar2000 (author)2013-11-14

Excellent work! I certify that these simple water based coolers are surprisingly effective.

oakback (author)rimar20002013-11-15

Only if the humidity is low. I always get excited reading about these and "swamp coolers", but when it's hot in my area, it's always very humid as well. Evaporative cooling doesn't work here! (Florida)

astral_mage (author)oakback2013-11-16

actually it can work prpoerly if u do yr research. many of the native tribes in the florida belt did the same thing but with larger pots. there are many examples that remain intact even to this day.

Calandril (author)astral_mage2013-11-18

Unless I understand it incorrectly, given the wet bulb temp of Houston average, Your fridge would not cool much lower than 77f on most days... I think the coolers you're talking about Astral, were the kind that were also buried near a river or other water source. The temperature of these pots could get down much lower, but out in the air (as this and any reasonable modern version in any regular subdivision would have to be) won't go much below the wet bulb temp.

So Oakback is correct. We do not use swamp coolers in the south because the humidity is so high. This reduces the evaporation rate, raising the wetbulb temp, reducing the efficiency of such a cooler
According to: TLA = TDB – ((TDB – TWB) x E)
TLA = Leaving Air Temp
TDB = Dry Bulb Temp
TWB = Wet Bulb Temp
E = Efficiency of the evaporative media.

Without the added heat sink of a subsurface flow, you just can't get low enough to do better than our AC's already does. In fact, as the AC reduces the temp in a humid environment, the air becomes more saturated as the relative humidity gets closer to 100%. This means the wetbulb and dry bulb temps are pretty much the same in a house using AC to reduce the temp in Houston or Florida when it's humid.

Yes, the natives used swamp coolers to keep food better, but their methods are impractical for most, and if you have an AC, not very useful.

VadimS (author)rimar20002013-11-14
These types of coolers will keep the inside at just above the wet bulb temperature.
If the part of the world you live in has low humidity it's perfect (swap coolers for home cooling work on the same principle).

jaxboy (author)2013-11-18

This is similar to a swamp cooler. I lived in Arizona, where the temperature would get to 112F occasionally in the summer. I remember one night when the low for the entire day occurred about 4:30 AM, and it got down to 100F! Anyway, we had only a roof-mounted swamp cooler, and the temperature inside the house never got above 80F. It was entirely adequate year-round, and very economical, especially compared to a traditional A/C.

tauhid (author)2013-11-17

This cooler was called “aka Zeer” (pot ini pot) created by Mohammad Bah Abba (Nigeria) in 1995 and awarded Rolex Laurante in 2000. This cooler has been used in Africa as important life saver by keeping foods for a longer shelf life (more than 24 hrs) by reducing the temperature down to 15 degrees Celcius.

tauhid (author)2013-11-17

More than ten years ago such a refrigerator reported helped many Africans to keep their food or vegetables for a longer shelf life. I'm not sure who did but such a food cooler designer had been awarded by international organization (WHO?).. About a year ago I proposed such a use in my facebook account for Indonesian remote populations who have no electricity.

Ilan Voyager (author)2013-11-17

Many thanks to the author for this very nice and well made instructable, It's good to remind that there are ancient and effective techniques for cooling. As some have already pointed it works only in hot and dry climates. In Spain the "botijos" for cooling the drinking water are common.

gingerely (author)2013-11-17

To make this work (chill) even faster, I would soak the pots in clean water beforehand. Then put them together with the dampened sand as you have done. Maybe even put the whole thing in something that will hold enough water to keep the pots moist.
Nice instructable!

primosanch (author)2013-11-17

Nicely done.

vincent7520 (author)2013-11-17

This is the basic cooling system by evaporation? And let me tell you, it works great !
The same idea has been use by putting large jars full of water in egyptian house where the could pass a stream of air that was cooled by passing between the jars and the refreshed ai cooled the house. The technique worked for centuries in Egypt and other countries in the region … 
In rural France (before the 40's I saw many butter jars that prevented butter from melting by covering the butter pot with a cover that that was designed to contain water that could evaporate.
You certainly will not get a chilling effect … but it will keep food and dairy stables at a reasonable temperature under strong heat.
The basic ot what on may call "pottery refrigeration" is to use non varnished pottery for you can soak the part you want to be evaporated first in the water (ie cover) Ideally no varnished pottery should be used at all because … the higher the evaporation rate the more efficient the system will be

ManifoldSky (author)2013-11-17

Being that at no point in his comment here did astral_mage do that, I am at a loss as to what you believe your point is.
Feel free to quote where he does.

sdartnut (author)2013-11-17

Thanks for sharing this. I think I have seen something smaller for keeping butter cool on hot days.
Your instructions were well presented.

Steamcrunk (author)2013-11-14

Neat instructables. So it will keep veggies like tomatoes and ginger, as well as yogurt cool?

Yes ofcourse! It will cool down everything (exept icecreams).

well done, I love it.

onemoroni1 (author)2013-11-17

This is a good instructable. Thank you for sharing.

BCWatson (author)2013-11-17

Very good instructions! Could you explain a little how this works.

devangs3 (author)2013-11-17

I use a similar one at home, it seems similar to a traditional arrangement in our locality. Still, its good work :)

nreed4 (author)2013-11-15

Could you use salt and water to lower the temperature even further?

diy_bloke (author)nreed42013-11-16

I am not sure if salt and water would make a difference. The principle here is evaporation and salt does not do anything for that, might even harm it.
The reason why salt-water combo can get cold is because salt lowers the freezing point so the water can get colder (below zero) before it turns to ice, but in itself it does not cool at all

Chitlange Sahas (author)nreed42013-11-15

Will try

diy_bloke (author)2013-11-16

Great Idea Chitlange

BG_instructs (author)2013-11-15

Greatm whats the science behind this?

PS118 (author)BG_instructs2013-11-15

The phase change (water evaporation) consumes heat energy and cools the pot. Similar principle to how sweating helps us cool off.

PS118 (author)BG_instructs2013-11-15

marcellahella (author)2013-11-14

Cool! How much water do you pure in? All the way full?

Not all the way full ! Jut providing the inner pot a damp environment.

Not all the way full ! Jut providing the inner pot a damp environment.

About This Instructable




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