Build a Solar Food Dehydrator—Easy, Inexpensive, Detailed Plans
Thursday, 23 August 2012 00:00  |  Written by Tonya Kay | Article

Solar Dehydrator photo courtesy of Tonya KayWho doesn’t love dried fruits and vegetables? There’s the extra sweetness and concentrated flavor. They can be eaten “as is” or reconstituted with water. They’re lightweight—easy to carry to class, to work or even around the world. And don’t forget their environmental friendliness: they can be stored nearly forever without refrigeration, they don’t need to be cooked to be enjoyed and, unlike so many other foods, they don’t come wrapped in excessive packaging (especially if you make them yourself).

Under the right conditions in the right climate, certain foods dehydrate naturally. But you can build your own food dehydrator to create favorable conditions wherever you are with the free plans below.

Raw vegans have a special appreciation because they believe, and scientific investigation bears out, that produce heated to no higher temperature than the sun would, retains its nutritional integrity and life force.

However, raw-fooders aren't the only people who enjoy using food dehydrators. Backpackers make lightweight soups, homesteaders make winter seasoning blends, naturalists dehydrate healing herbs, and some dads make mean all-fruit roll-ups.

There are many food dehydrators on the market, but by constructing one yourself, you can build it to your size specifications and make it completely off-grid.

If you like a lot of dried food, or like giving it away to friends, you should consider building a roof dehydrator. It’s fun to assemble, easy to use, and is powered directly by the sun and wind (which means no waste of energy and no increase in utility bills!).

A rooftop food dehydrator works by using the color black to draw in the sun's heat through a clear barrier. The heat then warms the air, which rises and is directed through screens with food on them.

If you are a true DIYer and have a set of tools to tinker with, go for the hardcore solar-food dehydrator like the one pictured. For the really hardcore, the rawer than raw, the useful object recyclers: why not use all reused or compostable materials?

My solar dehydrator, for example, is on a rooftop in Hollywood, dehydrating nine months of the year, so the sun is providing a generous power supply. Here are some tips to build your own:

  1. Drill holes in 3/8" Window Grade Lexan door to be attached to the box painted black for absorbing heat.

    Solar Dehydrator photo courtesy of Tonya Kay
  2. Install flashing over raw Lexan edges for skin safety. Notice the shelf mounts inside the box.

    Solar Dehydrator photo courtesy of Tonya Kay
  3. Using recycled window screens cut to fit new dimensions, it is now time to roll in the new aluminum screen.

    Solar Dehydrator photo courtesy of Tonya Kay
  4. Here it is fully assembled and positioned (illegally) on a Hollywood rooftop. But really, what landlord would scoff at these environmental and money-saving efforts? Notice the lid props for safe bracing while loading and unloading the dehydrator.

    Solar Dehydrator photo courtesy of Tonya Kay
  5. An aluminum screen at the top and bottom of the box allows ventilation and prevents birds and insects from entering.

    Solar Dehydrator photo courtesy of Tonya Kay
  6. The legs on casters allow for easier moving, though the Lexan on this bugger weighs a ton!

    Solar Dehydrator photo courtesy of Tonya Kay
  7. Earlier in the day on my hand-crank blender (another human-powered kitchen appliance) I blended up: 20 medjool dates, one lemon's juice and one teaspoon of organic cinnamon and spread over one-and-a-half quarts (soaked volume) of buckwheat groats. I am scooping them onto two food-grade silicone baking sheets, though unbleached or recycled parchment paper has proven to be a preferable option due to its ability to allow better airflow.

    Solar Dehydrator photo courtesy of Tonya Kay
  8. The other shelves are lined with unbleached parchment paper that can be washed and reused instead of being thought of as disposable (what does that word mean, anyway?). Notice the dehydrator's handle is made of wood, which does not absorb the rooftop's heat so I can grab it to open! Other trays hold kale chips and sweet potato chips.

    Solar Dehydrator photo courtesy of Tonya Kay
  9. Ravenous Do-It-Yourselfers can hardly wait to celebrate their teamwork!

    Solar Dehydrator photo courtesy of Tonya Kay

The above concept can be used as a guide to concept your own customized dehydrator. This is a pretty simple design which should be transparent from the photos. You will need the usual hinges and screws for attaching. If you have tools and even limited experience building things, it shouldn't be hard. Proceed as you would with other conceptual designs and base the dimensions of the box and cover on what is available on your rooftop space—and how much dried food you want to produce.

Certainly, you don’t have to build a solar dehydrator as big as mine. You can find plans below for a small, easy solar dehydrator that can be built in a few hours for less than $10. Tailor the plans to fit your specific climate, space and food needs. But do build one.

I mean, how cool would it be to send your child to school with a luscious whole dehydrated banana in her lunch box? How about some date-sweetened "buckwheaties" with hemp-seed milk for breakfast cereal? Or you might want a work snack of apple slices spread with sun-warmed coconut butter. It's easy to replace potato chips with a more mineral-packed variety, and if those kale chips were dehydrated in your personally built, solar food dehydrator made from recycled material, what could be greener about your late-nite snacks?

Help the Earth, Spread the Word: Share this article with friends. Copy and paste this shortened link http://bit.ly/9IFEiE or click on the "Email This" or "Share This" links below right.

Additional resources:
Hardcore Solar Food Dehydrator Plans (pdf)
Simple and Fast Solar Dehydrator Plans
The Solar Food Dryer: How to Make and Use Your Own Low-Cost, Sun-Powered Dehydrator
DIY Projects for the Self-Sufficient Homeowner: 25 Ways to Build a Self-Reliant Lifestyle
Other writing by Tonya Kay on EcoHearth.com
The Clean and Green Everyday blog by Tonya Kay
Other easy DIY environmental projects

[Sign up to be notified each time Tonya publishes a new Clean and Green Everyday blog entry on EcoHearth. See a complete list of writing by Tonya Kay on EcoHearth.com or visit her Clean and Green Everyday blog. – Ed.]

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Comments (30)add
Written by Tonya Kay , October 22, 2013
It's about 4x4. The important thing is of course to measure it out according to the (salvage) materials you have at hand so the shelves match the box and the lid matches, too. Obviously. I'm a very creative designer.
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Written by Mario , October 21, 2013
What are the measures of the box?
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Written by m , August 23, 2013
I've seen this one before. Only came back to ogle that hot handyman again. What a fine specimen he is!!!
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Written by Joannarenee , July 14, 2013
Big question. What kind of black paint do you use. I have read about many solar projects and some complain about fumes and odors from the paint. So what paint is "safe" to use.
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Written by Tonya Kay , July 12, 2013
Hey, C! Florida's humitity and rain will be harder, but if it were me, I'd tweek it for the climate. Build similar to the one I built (or smaller:-) and see how that works. If you food just isn't drying, then cover the vents at night, which is when most of the condensation happens. See how that does. If that still doesn't work to get the food drying enough, more air flow would be the key. The indoor variety use a small fan, so you could use a fan at the bottom vent to blow upward, too. Of course that will cool off teh interior, so getting a nice ratio of air flow vs temperature is dehydrating key! Knowing you live in a high humidity / high rainfall location, I do suggest making your first solar food dehydrators out of inexpensive or free materials. You WILL have to tweek and rebuild. Even a cardboard box painted black inside would be a nice start for housing while you are experimenting.
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Written by TomM , July 10, 2013
Add a thermometer and vents. A solar box can "cook" when you really want drying air flow. Also screen to keep bugs and mice out.
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Written by C.Cannon , July 10, 2013
That looks awesome. I've saved the instruction to give to my son. Not really sure if it will work here in SW Florida when our humidity is always super high..... ? But we are going for it.. Thanks for the great idea.
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Written by Tonya Kay , April 29, 2013
Rick, thank you - yes, exactly - I hope that readers already have tools and are experienced building a few DIY projects when they consider this guide. Leland, I come up with my DIY designs right out of my head to fit my personal application, so YES everyone should do like Tami and use what materials they can repurpose to fit the space, geography and climate they live in. And even if the article simply inspires beautiful memories like Sophia's, that's what it's for as well. The simplest solar dehydrator is indeed just placing the fruit on a screen in the sun! It's a tradition with grapes in Amarone, Italy to concentrate the sugars slightly before fermentation by placing them in the hot weather (in the shade) on straw mats for air circulation - the result is an Amarone style wine with a thick mouth feel and higher alcohol content, more like port, but not so brutal. Worth a taste: http://en.wikipedia.org/wiki/Amarone
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Written by Tami , April 28, 2013
This makes me think about all of the materials I have laying around the property that I could use to make this. I have a set of wood steps that came off of my deck that I took apart.I could finish closing the steps in (the rise) and maybe line them with aluminum foil. Then I have these great old sliding glass doors that I found on the roadside that could be the top glass. I would hinge the glass door to the steps probably on the side since it is so heavy. I love seeing ideas where I can use my imagination about repurposing stuff instead of buying new. Thanks!
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Written by Leland Stone , April 28, 2013
The idea presented here is sound and provides a sufficient template for any reasonably accomplished DIY-er to follow. The author clearly advises that readers adapt his idea to available resources, reusing and recycling where possible, thus it's not practical to provide a bill of materials and a cut list (both of which are provided with more traditional building plans).

The idea presented here is a good one, and readily adapted to individual skills and resources, thanks for sharing it.
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Written by Sophia , April 28, 2013
What a great idea, though i cant build to save my life. i want a dehydrator so bad, im even willing to build one myself to get it!! When i was young, we lived next to a cute elder couple from Italy. they would tend to the tomatoes, like they were their children. you could see them outside spreading the tomatoes on a board in the sun, and allowing them to sun dry. we would always get a jar of those delicious tomatoes made into the best Italian sauce. Yummo!
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Written by Rick , April 28, 2013
Leonessa1122, the writer did not provide specific sizes for the box since each reader will have more or less space available. You can use the photos and instructions provided here as a jumping off point to customize your own dehydrator to your own needs and space. It does assume that you have tools and some know-how, such as building a frame (four pieces of wood, nailed or screwed together in a box shape) and a stand (two or more, if your box is big like the one pictured, pieces of wood attached to the frame by nails or screws) that the box leans on to keep it at the best angle for the sun. However, there are included, at the end of the piece, links to other examples of plans that can inform the design you eventually settle on. I hope this helps!
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Written by Leonessa1122 , April 28, 2013
These instructions are far from detailed. It says nothing about how to build the box, or where to get the box, or what to make the box from. Suddenly it says, "Drill holes in 3/8" Window Grade Lexan door to be attached to the box.." Then you attach aluminum screen..to what? And how do you make the framing that allows it to lean like that? How much will this thing cost? This is, in fact, quite vague.
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Written by tonya kay , December 26, 2012
Oh, Linnie, that's a gift to me and the environment and your health and electricity bill, too! What great news!
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Written by linnie , December 25, 2012
Thank you. Years ago I meant to build a solar dehydrator, and never did. Recently, I've got the bug again after watching how tedious and energy-consuming the commercial domestic dryers are... These solar dryers look fantastic... :)
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Written by Drew , May 13, 2012
I need more specifics on materials list. Somethings on the PDF material lists and build descriptions are just a little vague for me. I need elaboration. I'm perfectionistic and follow directions to the tee and find it hard to figure what some of this is saying. 1" x 2" 120 FT? that can't be right can it? Can you please help clarify this for me. Thanks. I'd like to build this large one for myself and a few other people. Thanks for responding.
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Written by sara stillman , March 21, 2012
wow this looks really awesome and i think that I can manage building it, it definitely looks ideal for dehydrating a lot of fruits etc. Its really great that its solar too, thanks for the instructions!!
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Written by Elizabeth , March 14, 2012
Good stuff! I'm wanting to build a dehydrator in central america. It can be 30 degrees celcius or higher for much of the day, maybe dropping to 20 degrees in the morning/evening.
While it is dry six months of the year, the time of the year we have the most fruit to dry will be the most humid months. Which kind of design would you suggest?
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Written by Tonya Kay , February 27, 2012
How often does it rain, what hours of direct sunlight can you offer and how hot does it get?
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Written by Orlando Neus , February 27, 2012
New to this topic but I am very interested I live in an country right on the equator north east coast of south america 35* deg Celsius 90% + humidity two seasons of rain and drought.Question which solar food dehydrator would be the best for me to use the days are short.
will be very obliged with your professional opinion.
Kind regards
Orlando
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Written by tonya kay , May 29, 2011
India! wow how exciting! even if your country did sell electric dehydrators I'd still encourage the electricity free style. if your climate can support it. you will need five day stretches of sunny days to use direct application solar power. I'd say if the seAsonal temp has a high of at least 70 f and low above 60 that's a good start. also consider the humidity. but in this style of dehydrator you are the thermostat. your relationship to the process regulates the temp. it becomes intuitive in short time. I placed a auction cup air temp thermometer on the glass inside. at first I'd check it every two hrs - if too high temps, prop that door open. if too cold, plAce a towel over the top vent to raise the temp. now I just know.
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Written by Elise , May 28, 2011
Hello, Was wondering if there is some way to build this with a temperature controller? I live in a country that doesn't sell electric dehydrators (we don't need them here in India, but I live in the Himalayas where it doesnt get hot enough just to let the sun dry things + Lots of bacteria etc). I want to start cooking more RAW meals for my family. Any ideas on how to add a temp control?

Thanks for listening!
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Written by Tonya Kay , March 08, 2011
Since I'm a vegetarian, I would never recommend it! But yes, I do make a raw vegan version of jerky quite effectively in the solar dehydrator. It's dehydrating strength is contingent upon the hours of sunshine and heat that you get in your region. For example, my raw vegan jerky consists of a spiced brazil nut meat wrapped in nori sheets. This is a thick, fatty, long-term dehydration food. And to dehydrate this food in the solar unit would take three 9 hour 85 degree days. In other words, you can choose your foods for dehydration appropriate to the season, since we are working with sunshine as our fuel-source here. A warm, sunny summer day is necessary for some items.
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Written by Mike Bumgardner , March 08, 2011
Can you make jerky with this set up ???
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Written by Tonya Kay , January 17, 2011
What country will you be moving to? Direct solar application is the most sound reasoning for power supply I have encountered. Instead of turning solar into energy stored in a battery, which is inefficient, but still practical, we could first consider how directly to use the heat and light the sun generates. Water heating, food dehydrating or cooking, clothes drying, paper drying - all ideas for direct solar energy application. Oh, let's not forget the direct solar application for humans: Vit D production and the most powerful anti-depressant available. Shine on, benevolent sun!
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Written by Laura Dreyer , January 17, 2011
Thank you for this fabulous article - we are moving to a country with erratic power supply but masses of sun - so now I have a dehydration solution. I'll spread the word as your tips are practical and through. Thanks again.
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Written by Terry Parks , January 31, 2010
Great one, Tonya! I love ideas for things I can build myself. Your other columns have wonderful practical advice which makes me feel like I'm making the world a better place one thing at a time. Thanks!
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Written by Auggie , July 21, 2009
Very nice design! Am looking at building one as I have a large pear tree that is loaded to the max with fruit, thanks to cool and abundant rain in New England. The only question I had was will the direct sunlight hurt the food you are dehydrating? I have seen another home model that blocks the direct sunlight. Comment?
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Written by Tom Croom , June 22, 2009
I am truly a sucker for banana chips... always have been.

Just sayin'

Good article :)
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Written by Wendi Dee , June 22, 2009
EXCELLENT article! Feel free to add links to the AllRawDirectory.com for any of these raw food articles. Many people would love to come here to read the helpful information you are sharing!

This is an awesome idea to have an off-grid dehydrator! I've seen do-it-yourself ones that require electrcity, but this one is totally RAWESOME!

After our tour, when we settle down, we'll be coming back here to find the directions to build one for ourselves, too! Thanks for sharing the information!

Lots of love,

Wendi
XOXOXO

p.s. You have a beautiful assembly person putting your dehydrator together! *blows kisses*
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