Ben's DIY Solar Food Dryer

[bennelson]

Hi everyone!

This summer, my wife and I joined a CSA - Community Supported Argiculture.

Basically, you "buy-in" for a share of whatever a farmer grows during the season. The trouble with that is you may end up with a whole bunch of who-knows-what that you can't possibly eat at once.

Wouldn't it be nice to be able to preserve some of that for the winter without canning or buying a (energy-gulping) freezer?

So, I tried building my own solar food dehydrator.

I had a few misc parts around, and figured I could build one out of junk for basically no cost.

First, I built a box out of foamcore and scrap 2x4s, then added glass to the top and plexiglass to the front.



I had two 12V DC computer fans that I attached to holes on the back top of the dryer.



Those run to a spare 12V battery from my electric car project. That battery gets charged up by a 15-watt PV panel.



Thus, the sun can shine in during the day and help dry, and the fans can run 24-hours a day, but still be solar powered. There are three holes cut in the bottom front of the dryer to allow in air, which are covered by a bit of screen to keep the bugs out.

Inside the box, I have 1x2's screwed to the side to support the screens. Those are recycled modern window screens which have been well washed.



Food is prepared by washing/peeling/slicing and getting laid out, single layer, on a screen. The screen goes inside and the fans pull air through it for a couple days.

So far, I have done tomatoes, basil, apples, pears, and peppers.
Tomatoes can stick to the screen. The basil got amazingly dry. Apples were good, but the pears almost turn into candy.

Here's a tomato after a few days in the drier. It gets sweeter, and is great in salads and pastas. (No I didn't Photoshop the clouds...just good exposure on the camera.)


Last night, I cored, peeled, and sliced about half a 5-gallon bucket of apples. After all that work, it came to about a screen and a half of slices.


I found that the apples were small enough that I could slice an entire apple at a time with my hard-boiled egg slicer, although it didn't cut as clean as a knife.

You can also see all these photos on Flickr by clicking the following link:
solar dryer dehydrator construction - a set on Flickr