Garden, Camping & Festival No Electricity Fridge!

Intro: Garden, Camping & Festival No Electricity Fridge!

It's getting hotter every day and your electricity bills are not environmentally friendly.

This credit crunching fridge is a sure way to be sure your beverages will stay chilled in the hottest of heats.  It's much greener than your average electrical fridge and will work anywhere where there isn't a lot of humidity.

The pot in pot refrigerator or Zeer was made by Professor Mohammed Bah Abba, though there's evidence it was in use in early Egypt.  It works on the principle of evaporative cooling.

You will need:

Two terracotta pots.  One has to fit inside the other with an inch or so between all the way round.
Sand.
Water.
A towel/cloth big enough to go over it
5-10 minutes, maximum!

STEP 1: First Pot

Add about 1-2" of sand into the bottom of the big pot.  Don't worry too much about the holes at the bottom, the sand packs down and forms a plug.

Firm down the sand before putting your second pot in.

STEP 2: Filling the Pot With Sand

Put the 2nd pot into the first, and start packing the sand round the edge.  Layer it and firm it as you go - this ensures the pot stays straight.  Don't worry too much as it'll self correct in later stages.

The last image shows me stopping filling a little way down from both rims - the pots are pretty much flush with each other.

STEP 3: Watering

First use a jug or hose to gently wet the sand.  The first time you wet it, the sand may sink.  This isn't too much of a problem.  You're trying to water log the sand as much as possible.

The terracotta pot is porous, so it wicks the moisture into the external pot.

The sun and wind evaporate the water which causes heat loss - effectively cooling the inside.

To cover, use an old towel and wet this as well.  You could put one end of the towel in a reservoir (a bowl of water) and it would continue to wick water up onto the top and evaporate causing more of a temperature drop.

STEP 4: Fin

Within about an hour, the cans had cooled from warm to quite chilled, enough that when removed, they had condensation on them.  Not bad for a particularly varied conditions of Britain.

Comments

[Chang1821]

How Long does this fridge last?

[spark master]

how cold do they get, actual temperature difference. If you are in Britian and it works then the drought must be fierce cause you are not in a "dry" place. We here in the USA like our beer much colder, but this would be nice for water bottles, (reusable of course, cause ,( ferget the enviroment for a moment), they cost a fortune. If these make something say 20 degrees cooler and it is 100 degrees outside then that beer is 80 degrees, yeck. Ok for scotch maybe with a cube, but not a nice DinkleAcker Dark. That requires an American beer fridge set at about 36 degrees F and 24 hours of cool , then an insulated mug /stein/bottle wrapper. Boy does my gout ridden toe scream when I discuss beer, natures most perfect food!

[Bspoony]

long time ago but you may still be there. I used this principle in the Iraq desert. A wet sock and soda can. The hotter the outside temp the colder you can get it, so long as you have moisture that is, anything that will evaporate to cool the 'machine' and I have frozen soda with water and a sock left in a breeze in direct sunlight and periodically made a little wet

[spark master]

I will give it a try we get off shore breezes here, If you remember shoot me a reminder in the spring. I have heard these work for a few degrees, frozen water however thin sounds boastful, but heck I was not there, so I will need to try it for myself. Also you were in a dessert and the air IS DRY, add to that the air temp in desserts drops quite a bit at night w/o water masses to absorb and release later. So if the air is at say 40 it is dry and you can get a 10 degree drop by evap. shoot we are talking beer temperature ...mmmmmmm tatsy

I have also read in various places if you make a parabolic type reflector and put a water bottle in the focus then point it away from the moon, over night , you will get very cold water , thin film of ice, in summer. I do not believe it, until I do it. This all sounds like a "free lunch", so it remains a show me experiment. I will pass this on to an engineering student I know, should be fun for the class to try out.

Evaporative coolers are a very old, ancient concept.

see the wiki entry

http s://en.wiki pedia.org/wiki/Evaporative_cooler

they do work well in places like aridzona or iran but the UK perhaps not so much, or here on the east coast of the US

[Bspoony]

you are totally correct and I doubt the complete effectiveness for freezing in the UK for those very reason, however, the benefits we have during our summer is that if you wet the cooler overnight before your party it will likely still be frozen the following day lol

[tim_n]

Nice!

[Arano]

the temperature difference is dependend to the temperature where u use it and the dryness of the... and if you really like beer that much you should take a trip to germany ;)

[spark master]

I doubt I will ever have the spare cash to go to Europe. Mr Bush and the repugnican party screwed the middle class here. I would like to go to Italy for a month , just to goe to Roman sites and eat . Then do France (foo, useums as well) then Briton , (not sure why) then Germany for a month , just to find the best pilsner. LOTSA taste offs.

ciao

[tim_n]

I do regularly :) Munich is a lovely city with many wonderful beer gardens :)

[Arano]

i hope you visit more than just munich, else you'll miss much of what germany has to offer to visitors ;)

[kelceybrackett]

Only bad beer needs to be that cold.

[spark master]

Sorry I am a yank, I like it cold under 40 degrees. But I notice in German bars they have a fill lne strictly observed, but in British/Irish Pubs ,(here and on BBC tele shows), they fill them to the tippy top. My kinda beer glass, FULL! (soon to be emptied, then refilled).

ciao

[ducktape.mac]

would plastic pots work?
i'm on a VERY tight budget and i just looked on lowes.com for the prices and they got pretty pricey.
if it's possible, could you please answer fast?

[tim_n]

Will only work with clay pots because water has to soak through and evaporate to cool the pot. You are exposing sand which does the same thing but which doesn't have the surface area.

What you can do instead is use any old pot filled with water and put a tea towel over the top but make sure it goes over what you're going to cool and into the water. The tea towel wickes up the water and evaporates it to cool. Same principle but doesn't have the same thermal mass and won't last as long.

Obviously requires more water which the zeer doesn't require.

[ducktape.mac]

would you mind explaining what a tea towel is? is it just like a rag or something?

[blodefood]

I think it helps to keep the cold in better and keeps out bugs and dust.

[ducktape.mac]

okay, thanks. that helped a lot.
i plan on making one today!

[LobosSolos]

Looks nice, only problem is it would never work in Arkansas.  We're notorious for having high humidity when we have heat, so evaporation wouldn't happen quickly enough to cool anything.

[graydog111]

You are correct about it not working in Arkansas, LobosSolos, but in west Texas, and New Mexico, evaporator coolers or swamp coolers get the house really cold.

[justin.jackson]

i was literally about to start doing and instructable on this very same thing.