Instructables
Picture of Solar Food Dehydrator (Dryer)
Dry your fruit, vegetables, and other goods with your own sun powered dehydrator. Electric Food Dehydrators can be expensive and consume unnecessary energy.

This solar dehydrator was made entirely of recovered materials. It was constructed with scrap ply wood, 2x4s from an old ladder, a house window, and other items which could be considered trash. It was created as a project at Maharishi University of Management in Fairfield, Iowa.

Why We Dry: Removal of moisture prevents bacteria from ruining your values fruits and vegetables. Drying is a form of preservation.
 
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Step 1: Learn the Design

Picture of Learn the Design
Become familiar with the design to minimize mistakes...

There are vents underneath in the front which are hidden in this picture. The darker section is a piece of heat absorbent material, we used painted metal for this particular dehydrator, but other materials will do as long as they are dark. The food itself is placed on the shelf, which will be made out of a cloth screen. Other screen-like materials can be used, but take chemical leeching into consideration to prevent contamination. The back piece of ply wood can be opened to remove the shelf and provide additional ventilation.

Step 2: Find Materials

Picture of Find Materials
Thin Ply Wood (Body)

4 2.5' Long 2" x 4"s

10 feet of 2" x 2" wood (Braces and drying shelf support)

A Window (20" x 23 1/8") or a suitable slab of clear plastic.

Screen (For covering vents)

Stretchable Cloth/Material. We used stalkings. (For drying rack)

2 Hinges

Screws

Staples

Thermometer

A Hook & String (To fasten the rear door)

Caulk (For perfectionists)



Step 3: Size Pieces

Picture of Size Pieces
Here is a checklist for the plywood pieces.

-1' x 23 1/4"' (Top)

- TWO 20" x 12" x 26 1/8" x 14 1/8" (Sides) This has a diagonal cut.

-26 1/8" x 23 1/16" (Bottom) This will be trimmed to fit legs and vents.

-14 1/8" x 23 1/16" (Back) This will be on hinges.

*Careful Cutting
gcai_fwb4 years ago
Great Idea and instructable!

However for use in more northern climes the sun is not enough during the cooler months and we have to resort to electrical methods.

Rather than using a stand alone dehydrator I've found a single 100W incandescent light bulb placed at the bottom of the oven of my stove works very well, creating sustained 150-160 degree heat.  I've added a light dimmer to vary the bulb intensity ie. a heat control - a little expermentation and I have a cheap and effective dehydrator with relatively low running costs. For more heat add light bulbs or a combination of different wattages.

Note: CFL bulbs will NOT create the desired heat. 
just a tip ...try instaling a hairdryer motor on a timer ...we use it for making biltong (jerky) and it really works great.
Now THAT I like. I might be able to wing that in my little brooklyn apartment.

Isn't it a bit loud?
YIP its a bit loud but mine is outside in a shed.Just run it when your not around to hear it.All its doing is speeding up the drying by evacuating the warm air with the moisture in it. It works well with just with A 100W globe but takes longer.Do not try to run a hairdryer on the hot setting as you want to dry not cook and i assume you do not wanna burn the building down.I run it 15min in the hour so as not to burn out the motor.
diy_bloke afridave11 months ago
I like your idea but as a real guy I would be using a 2000Watt hot air gun that is used to bend pipes and strip paint :-)
Nothing like having yr jerky done in 5 minutes :-)

(Sorry, the idea is stolen from 'Tool Time' in which Tim Allen builds 'a manś kitchen', using an acetylene blow torch to roast turkey. Could not resist :-) )
If the climate is too cold for a solar dehydrator you can make this wood fired one that will also be adaptable to  your amount of dehydrating crops. Also most of the materials can be picked up for relatively inexpensive.
www.backwoodshome.com/articles/hooker41.html
sthomas83 years ago
Well this is simply lovely and i would love to try it with the local apples that are just coming into season here in new england but its too dern cold. But I had an idea of using the suction from an overhead stove fan to move heat from a gas burner through a dehydrating chamber and out of the house through the fans exhaust duct. Any feed back that might help me on my journey or prevent me from burning down my house?
You'll have to be careful not to cook the apples instead of drying them- a light bulb gives of plenty enough heat to dry them. Should work, though, as long as you can keep the heat down
I ussed a little different system for heating. I used a 60W bulb and the temp went to 140 deg in 40 minutes. I loaded sliced bananas on a vinyl tray and in 4 hours the slices had "glued" themselves to the vinyl tray. any suggestions? JJ
dropkick1 year ago
Have you ever thought about adding a sliding cover screened opening to the door or even the top of the dehydrator? You could adjust the temperature by adjusting how much it was opened, and with the screen you wouldn't have to worry about insects (like you would if you propped the door open).
jonesaw2 years ago
way cool, i think im going to try it out!
geofarm2 years ago
Here in the southwest at 6,000' our challange is controlling the heat. Living on an off-grid PV system we also consider choices for things using electrical current.

A fan option is the style used in cooling electronic equipment. Many are very quiet and use very little energy. Shop carefully - some run on less than 120VAC. Sources for used are numerous, no need to buy new.

I would add a chepo thermometer that can be mounted outside with the senson probe inside - something like a Taylor 9940 - maybe $19.00 new.
godbacon3 years ago
Good project!
I like the simplicity of the build/design.

some thermal mass would help even out the temperature. and it would be nice to have some kind of a swivel to follow the sun or another pane of glass to take in wider sun angle.. early morning to late day.

a more automatic temperature control is needed. something based on the expansion of metal to open a vent or flap, maybe. Some kind of leveling/stability is needed for those of us that don't live on flat land, don't want it tipping over.
Overall a really good job on the project and the instructable.

ANDY!4 years ago
I read a book on this! I made something similar with a pizza box.
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joanofarc4 years ago
 What is the purpose of the "feet" on the front legs?
Permaculture (author)  joanofarc4 years ago
It's hard to see in the picture, but the feet have little toes carved into them. It's purely aesthetic, nothing else.
unlvdating4 years ago

Thanks a lot for the post. I really want to learn how to grow plants using hydroponics but I don’t have much knowledge about this method. I appreciate your effort in writing articles or posts about hydroponics which helps me a lot in understanding matters about this amazing method of planting.

Climate Control

its really great to see some best thing created out of junk
DrChill4 years ago
For cooler climates, consider - double glazing. This can be glass or clear plastic film wrapped around the window.

Also consider thin insulation; either rigid foam or aluminized bubble pack.
This may solve the - not hot enough problem, but it may tend to over-heat sometimes.

Yours is a nice design/ idea, but my only concern is that there is no temp/humidity control mechanism.

There are green-house roof window controls that open & close depending on the temp. Maybe something like this could be added to the design.
nfarrow4 years ago
What software did you use to make this?
Permaculture (author)  nfarrow4 years ago
Adobe Photoshop :) I just used the line tool and traced the realphotograph on another layer.
jessimata4 years ago
VERY NICE!
I live about four hours away from there. It's been so cold and rainy lately, that this wouldn't be of much use. I do agree that electric dehydrators consume lots of energy. They are kind of like ovens that run all day long.