Posted by & filed under Energy Systems, Processing & Food Preservation.

Most of you will be familiar with the pot-in-pot refrigerator by now. Well, today we’ll revisit this concept by taking a look at the ‘MittiCool’ refrigerator, a possible ‘upgrade’ that also uses evaporative cooling through the use of clay, but which looks a little more like the refrigerator you’re more familiar with. And, just like the pot-in-pot refrigerator, the MittiCool uses no electricity.

How does it work? The topmost section holds water, which very slowly drips down the sides. As permaculturists will know, one of many ‘constants’ we can count on and use to advantage is that evaporation cools. As the water evaporates from the porous clay surface, it cools the interior, enabling you to store fruit, vegetables, milk, etc.

There is even a tap on the front of the unit, so it doubles as a water cooler as well.

In the following videos you’ll meet the maker of MittiCool, and learn how it is made from a specific combination of four different types of clay he has found in his local area. The video states that the inside temperature of the MittiCool can be up to 8°C lower than the outside temperature.

This refrigerator will not function everywhere, of course. Evaporative cooling only works well in dry climates. But for those people living in the right conditions, this looks to be a very sensible, low-cost and planet-friendly way to extend the shelf life of your produce.

This use of natural constants in our designs will, I hope, become more commonplace as society finds itself unable to breach the peak energy impasse. Where previously we had energy to spare and so could just design with fossilised sunlight, we will instead be forced to find sustainable alternatives. It reminds me of the urban legend (myth) about NASA spending millions of dollars to create a pen that could write in the vacuum of space, while Russian astronauts simply used a pencil. Although not a true story, it does graphically illustrate how our industrial mindset leads us to overlook simple solutions in favour of ‘being clever’ instead.

8 Responses to “MittiCool – Clay Refrigerator”

  1. Chris McLeod

    Hi Craig. Nice post. Traditionally here Down Under, they used the Coolgardie Safe which relies on similar evaporative cooling techniques. It doesn’t have the thermal mass that the MittiCool system has, but I remember my grandfather had one in a bush camp up in the high country and it always fascinated me as a kid.

    http://en.wikipedia.org/wiki/Coolgardie_safe

    Reply
  2. Barbara Kovats

    This is really good to see – thank you!
    A question to Chris McLeod: Is such a refrigerator as you describe it still in use or even to be bought?
    We work on a solar Testfield in Tamera and would love to shocase these technologies – especially as cooling is one of the most important energies for kitchens in sunny rich countries.
    Looking forward to hear from you,
    greetings
    Barbara Kovats

    Reply
  3. M. Ravindranath

    I live in Bangalore (South) and I wish to know who can supply Mitticool Fridge to me locally. Kindly send me ur Bangalore dealer’s Name/Address/Tel.No./Mob. No. and ur most competitive price.

    M. Ravindranath
    H-203, Soudhamini Apts.
    Ashram Kitchen Road,
    Next to Sri Sri Ravi Shankar Ashram,
    Off 21st Km. Kanakapura Rd.
    Bangalore (South)-560 082.
    L: 080 6710 2442
    M: 098712 61714

    Reply
  4. Arun Deshpande

    I wish to purchase mitticool refrigerator for my house at Talegaon-District Pune.
    We have 30% RH and around 33 deg C temparature here in summar. Please let me know the nearest dealer/ outlet in this area.

    Reply
  5. esmee lane

    I live in nsw Australia and would like to bye a minicool, is this product available?.

    Reply
  6. Selene

    I really love this design. I live in Perth Western Australia and would like to buy a Mitticool. Are they available anywhere in Australia? Thank you for your reply.

    Reply
  7. Andre Busch

    I am in the process of setting up an ‘off the grid’ tipi camp-site and am investigating all I can on evaporation fridges. The pot in pot idea is great but too small for my application, I need space in each fridge for about 4 people for atleast 3 days.

    Have heard that larger models can be made building a double layered wall (filled with sand or charcoal) and if I had more time this would be a great project and I will eventually get to this. I need a quick time saving interim solution and my idea is as follows:

    Have sourced an old chest freezer and already taken it apart by separating the inside from the outside. Next step is cover the outside of the inner compartment (which is roughly 160cm high x 50 cm x 60cm deep) with chicken mesh. Lastly to roughly plaster onto and into the chicken mesh with a sand/cement mix to a thickness of around 3 cm. Once installed in its final position, to keep the cement wet with an irrigation dripper system.

    Before I do the whole hog I was hoping someone would be able to provide some valuable insight into my project which will enable me to make useful modifications. Would like to know if you think that the cement will work? My idea was to use lots of sand in the mix, therefore making it more porous and hopefully allow for better evaporation. I have no idea what else to use and have tried a small experiment with insulation material (as used largely in roofing here and is made from recycled plastic bottle such a 2litre coke bottles) but it does not readily absorb and internally distribute water when poured from above.

    Thanx
    Andre

    Reply

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