A Solar Food Dryer from Cardboard Boxes

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Making your own cardboard box solar food dryer is so easy and cheap, you might have to make two!

It seems that — at long last — a goodly number of people in government and industry are beginning to come around to the notion that, yes, there might be something to this sun-energy concept after all! Unfortunately, whenever the bigwigs begin “talking solar,” they invariably speak in terms of multimillion dollar projects, brain-trust technologies, and the all-too-familiar decade-long implementation schedules.

Well, all that may be necessary (although I doubt it) for some solar energy applications, but I’ve designed a solar food dryer that anyone — and I do mean anyone — can put together for pennies … and in minutes!

To build your sun-powered unit, choose a long, shallow cardboard box and cut a few holes in each of the narrow ends. That done, paint the inside of the container black or line it with black plastic sheeting — whichever is easier. Cover the box with clear plastic, and your heat catcher is complete.

Now, take another cardboard box and make several holes in one side. Then use some scrap cardboard and masking tape to form an air duct connecting the shallow “solar” unit to the side of the drying box. Set the latter on a table or stand, and lean the solar box against it at the most effective angle to catch the sun’s rays. Finally, lay a cloth screen on top of the drying box and deploy the food to be dehydrated on that surface.

If you really splurged on this device, you might be able to spend $1, but I doubt it! Granted, it’s not very permanent, and it’s certainly not waterproof. But, then, you wouldn’t leave your drying comestibles out in the rain or snow anyway, would you?

Note: Run the dryer for a few days without any food, to drive off any fumes that might be released from the paint or plastic.


The Solar Food Dryer book, by Eben Fodor. If you are thinking of building a solar food dryer, or you just want to learn the basics of how to preserve food by dehydrating, this is the best book available. Includes full details on how to build a very effective solar-powered dehydrator. Order now.