Friday, March 28, 2008

The Solar Dehydrator!


I made a solar food dehydrator so I could dry the extra food I grow. This way I will have some home grown food during the heat of summer when the heat is too overwhelming to grow much in Phoenix. The best part is that not only is it free to operate, it was nearly free to build! I based it off a plan in The Solar Food Dryer by Eben Fodor which I borrowed from the library. The materials were nearly all things I already had -- hardware, casters, glass, metal and wood. All of the wood was scrap that I had laying around the studio, the main box part is made from birch that I normally would use for paintings, but these pieces had various flaws that made them not appropriate for art.
I wanted to keep the Rachel-Dehyrator9000 plastic-free so I decided that stainless steel would be the best material for the food screens... I couldn't figure out why the book would suggest using plastic screening. After a lot of searching I finally found a warehouse that carried stainless mesh so I went down there and was escorted (after putting on a hard hat and glasses) to pick out my mesh. I found it exactly what I was looking for and then learned it would be $55 for 8 square feet! Now I know why people are choosing plastic. Lucky for me, they were kind enough to get some perforated stainless out of their scrap bins, cut it down and give it to me for free. :)

So here are my total costs to build the dehydrator:
2 hinges- $2.39
Friction hinge- $2.79
Thermometer- $4.79
-------------------------
Total Cost: $9.97 plus tax.

My first use on an 80 degree day, the internal air temperature got to 160 degrees with the vent door partially opened. I've been leaving the food out from 10am until about 4pm but I think it is ready to come in after about 4 hours. I expect to be able to run 2 batches a day during the summer. Which I think may even be faster than an electric dehydrator. Hooray for self sufficiency and sticking it to The Man!

Banana chips:
4 organic bananas: $1.16

One of the trays loaded up (2 bananas worth)

In the dehydrator

Banana chips! (after I ate a bunch) :)

13 comments:

Bad Human? said...

It's nice to see someone else doing this. My fiance and I want to build one this summer in order to dry fruit since the only store bought kind we can find comes in plastic.

N.

http://badhuman.wordpress.com

P~ said...

Very Very Cool Rachel! I am all about people building it themselves and yeah, sticking it to "the man" is the best! I've read that book as well, and plan to make myself a dehydrator this summer as well. I was able to procure a vented steel server rack from my work that is solid black and has a glass front! Repurposing is even better when it's free. Great post. I'll have to check back for sure.
P~

Tania said...

This is something I want to... no I NEED to try!

Melvin & Theresa said...

Wow! I'm am very impressed. I have a front yard garden. It's not much, but a solar dehydrator will be of great use.Love your blog!
3sa

Anonymous said...

Very nice to see your blog. I just purchased Fodor's book and have been trying to figure out how I can construct it without costing a fortune. Your solar dryer looks super and the price was right. Hopefully I can scrounge up most of the materials.

Show Low Bob said...

I'm a beginning chicken farmer and small garden grower. I have a real nice solar oven that I built and it really works well. I would like to build a solar dryer and have ordered Eben Fodor's book. I hope I can afford to build one like you have (although not at your cost). I just found your blog, but will be checking it often.

jennconspiracy said...

Nice dehydrator! I am just finishing up mine now and looking around for tips and ideas...

David LaFerney said...

Simple, affordable, and not made out of cardboard and plastic. Excellent. However, I hate to say this, but did you ever wonder what that birch plywood is glued together with? It might be a good idea to leave it out in the sun for a while to evaporate off any nastiness before actually drying food.

rachelbess said...

David-
I did think about that, and did exactly as you suggested. After I made it I left it out for awhile hoping it would heat up and force out the majority of the formaldehyde etc that is found in plywood glues. I am currently building a wooden solar oven out of wood and will be making it out of planks rather than ply. :)

d said...

Great work Rachel! What did you use for the frames of your drying trays? Is it ok to have the sun shine directly on the food? does it kill some nutrients? I am planing to make one with a separate collector and drying racks to keep the food in the dark which will be bigger but will be able to be left out in the weather so it doesn't matter.

rachelbess said...

d- The drying trays are a heavy enough gauge of stainless that they don't bend at all so they don't have/need any frames. As far as the sun killing nutrients, I don't think the light kills any more than the convection heat that actually does the drying, if so, I'm guessing a negligible amount. Also, the second tray is basically shaded by the top tray. Send me a link to yours when you build it, I'd love to see it!

Joseph said...

I see you are living in Phoenix, where it is pretty dry. Do you think a solar dryer like this model would be good in more humid climates like Austin, Texas?

rachelbess said...

I do think it would work in more humid climates. It would be slower, but if I can dry two batches of tomatoes in one day, surely you'd be able to do one.