“This is my powerless Fridge design that can bring temps from 96deg down to 64deg.”

Mr. Teslonian Inventions
In case you missed it, be sure to see Mr. Teslonian’s wood stove that runs a generator, produces gasoline, runs a fridge and heats hot water.


Comments

Evaporative Refrigerator no electric bill — 18 Comments

  1. The link to the paper on Scott Nielsen’s passive refrigerator no longer works. I recently visit one built locally. Operating since 1980. I have been asked to help with some repairs. If you could repost the paper or have a hard copy that would be very helpful. I’m hoping that with what I learn combined with the work of Tom Tailer’s Ecofreeze to create a larger refrigerator.

    • Sometimes people restructure their websites, delete content, etc. It’s not practical for us to fix every broken link, sorry. Just do a careful search with the exact title and maybe you can find it posted elsewhere.

  2. Evaporative coolers are great.

    However, I encourage anyone considering building such a device to dig a hole several feet down and stick a thermometer in the ground. Root cellars often will produce better and more consistent results, and are much more easily scaled to large sizes. Never have to worry about running out of water or other similar maintenance issues. The the temperature underground (once you go deep enough) will approach the average temperature at that particular site over an entire year.

    If one only wants a small cooler, just bury a barrel. Something bigger? Build an earthbag root cellar like have been shown in some of Owen’s designs here on this blog.

    It’s simple. It’s easy. It’s extremely effective.

    If someone is searching for far colder temperatures, there are other ways.

    Personally, I’d love to build a system like this one built by Robert English:
    http://fourmileisland.com/IceBox.htm

    Be certain to view the photos listed on the left hand side of the page.

    That refrigeration system is simply brilliant in its low maintenance and its simplicity. Of course, that system only works in a climate that has winters cold enough to freeze a big block of water into ice.

    For a deep freezer, I like the idea of a solar powered absorption freezer.
    The magazine article on page 20 detailing has a nice home built system.
    http://library.neit.edu/homepower/Files/HP53.pdf

    Those 3 options cover a wide range of cooling needs and are my personal favorites.

    Each one can be built into a structure for a minimum of additional cost, especially if one is diligent at finding free salvaged materials.

    • It’s difficult cooling food in humid tropical climates. Evaporation is very low in humid areas. And if it’s 90-100+ degrees every day… well, I guess the best alternative is a stream or river. Any other thoughts?

      • The Solar Powered absorption cooler is probably the best bet in tropical humid climates.

        An absorption cooler can also be powered by any heat source on a cloudy day, even a small wood stove.
        http://en.wikipedia.org/wiki/Icyball

        With such a device, it becomes practical to scale it up and even make ice.

        Absorption coolers are not a new technology, they’ve been around for a long time. Many RV Refrigerators powered by propane are absorption chillers.

        No reason why the heat source must be propane, it can easily be solar or wood. Many individuals have modified the old RV propane powered units to run on other sources of energy.

        • That’s right. I forgot about absorption coolers for this climate. Biomass wastes such as rice hulls are very inexpensive and can be used in wood gas stoves to fuel the process. Rice hulls are ideal because they will flow at a steady rate from a hopper. Dr. Paul Olivier’s stove design could be scaled up.
          http://www.naturalbuildingblog.com/esr-making-waste-our-greatest-resource/

          A small solar panel could run the fan. One side benefit is the production of biochar (rice hull ash), which works great on gardens.

          • I stumbled across this video showing an antique absorption chiller today.

            I instantly thought of you, Owen.

            Don’t let the title of the video fool you. The item shown is not an “evaporative” cooler. It is an absorption chiller.

            http://www.youtube.com/watch?v=_sZVN7UOXBE

            The ball on the outside of the insulated box gets heated using whatever means is available. Then it is allowed to cool again. Through thermodynamics, the ball on the inside of the insulated box cools the box, even forming ice inside.

            Note that the two balls are positioned at different heights. That difference in elevation is extremely important to the functionality.

          • Right. Icy-ball refrigerators have been around a long time. They seem to get favorable reviews. I wonder if very many people still use them?

          • I guess that depends upon your definition of “very many”.

            In my rather subjective judgment the number of Icy-Balls still in use is very small.

            However, RV propane refrigerators also are absorption devices. They are very commonplace. Most RV fridges also have an electric capability for use when the RV is hooked up to Grid power at RV Parks. The electrical components are usually the first to die in such devices, but the Propane Absorption capacity rarely is the part the dies. The number of salvageable propane powered RV fridges is very abundant and for very low cost, if not free in some cases.

            Those Propane powered fridges can be easily modified to use another source of fuel other than propane, even solar heat.

            Even if the plastic insulated box and door of a RV absorption fridge is severely damaged, it’s still possible to salvage the key absorption chiller components and build a new insulated box that fits with the design of a home. Then power it with excess heat from the cook stove, or a camping sized rocket stove.

            The amount of heat required by these devices is a lot smaller than most realize. Most RV absorption fridges are powered by a propane flame comparable in size to a typical pilot light.

        • I’d love to have a gas absorption air conditioner/chiller in the summer months. It gets unbelievably hot here. This wiki article covers the basics: http://en.wikipedia.org/wiki/Chiller

          The trick is to capture benefit from each part of the cycle and use the simplest design with fewest parts. Rice hulls would be my preferred fuel since millions (billions?) of people have low cost rice hulls available. Just some ideas at this point:
          – optional: use the combustion heat to bake/cook food first. Ex: have a little BBQ shop or bakery next to the house.
          – the excess heat then drives the chiller
          – the chiller cools the house
          – the resulting warm water is used for baths, doing dishes, laundry, etc.

          My preference would be to buy an affordable unit that could be readily adapted to a direct-fired rice hull burner. A small, simple one-room unit (without attached bakery/BBQ) would be very popular here. Ideas are welcome. Free plans would be the ultimate.

    • Here is another (better) link for the Heat Pipe refrigerator I referenced earlier with the fourmileisland link.

      http://nmsea.org/lib/Sunpaper_V5N3.pdf

      On page 17 of the above newsletter, Scott Nielsen describes in detail how the system is built and how it works.

      It’s a very ingenious concept. Of course, this design only works in climates that have winters that get below freezing.

      This design is different from the absorption chiller design mentioned in other comments. This is a heat pipe, not an absorption design. Don’t get the two confused. They work very differently.

      • That’s a good article. It also covers his summer kitchen/ice house refrigerator combo. I love designs like this that do multiple things.

  3. When I was in the Army we had a saying that applies here.
    Improvise, Adapt, Over Come. I’d like to try this using a metal box. It’s a good thing to know.

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