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Evaporative Cooling

Keeping produce fresh with refrigeration methods that require no external power.

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Kris Pope said:

Hallo everyone I am keen to try this out in our lodge. I work in the Serengeti National park in Tanzania. I have been searching the web for an actual design of a charcoal evaporative cooler. However I have just found write ups & pictures. Does anyone have a design? My mail address is Thanks

Commented on: 2014-03-19 17:36:00


Barrie Axtell for Practical Action said:

Dear Melanie

First I must apologise for not replying to your enquiry before. I have had computer problems and for some reason this one seems to have slipped through the net.

You are absolutely correct in that evaporative coolers work best in areas of low humidity. I would think 65 to 75% RH should provide some cooling perhaps 5C or so. Air flow is also very important, try and place the cooler in a place with wind. This will move the moisture away and assist cooling. It is also important to get rid of field heat as quickly as possible so a bath or spray of cold potable water before cooling will help.

Many years ago ITDG reviewed evaporative coolers in India and there is an article in Food Chain. If you would like a copy of the article please email

I can only suggest you build a small, low cost unit and test it to see what happens. A small reduction in temperature can have a profound effect on shelf life.


Barrie Axtell

Commented on: 2014-03-04 12:48:00


Melanie said:

Has anyone ever tried to build a charcoal cooler in an environment with 65-75% relative humidity? I work in Liberia on an agriculture project and we'd like to try the charcoal cooler to use with fresh vegetables just harvested from the field during the dry season - lettuce, cucumber, watermelon, bell pepper, onions, tomatoes, hot pepper. It would be temporary storage before transport to the market. Any advice? We will build a prototype to test in about a month.

Commented on: 2013-11-22 17:07:00


Usman Suka said:

Very wonderful, simple perserving technology. Just what we need here in Nigeria where we suffer from unstable power supply. Thank you.

Commented on: 2012-04-11 09:47:00


Mr Titus Lanre I was looking for someting like this for a long time for usu in my village it a well said:

I was looking for someting like this for a long time for usu in my village it a wellcome systeme thank you.

Commented on: 2012-03-29 21:27:00


Neil Philip Noble said:

The download seems to work now and to open. If you have probelms with the download then I can send the copy by email, just fill in the enquiry form.

Commented on: 2012-03-29 12:49:00


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