Build a Solar Food Dryer
Written onJune 01 , 2008
I built this solar food dryer about 15 years ago and I’ve been using it ever since to dry vegetables, herbs, and mushrooms. The design is similar to a suitcase. Each end has a simple screen–covered frame that allows warm air to circulate from the bottom, over the eight drying racks, and out the top, while preventing unwanted guests from getting to your food. This easy–to–build project is a great way to preserve food.
I started by constructing the sides of the dryer. They are made up of two pieces of 3/4” pine. The outside piece is 3/4” x 3” x 39”; you’ll need to cut two of these. The inside pieces are cut from 3/4” x 2 1/2” x 39” stock and they are then notched to receive the drying racks (See detail for measurements). To assemble the sides, I simply glued them together.
Next, I made the frames for the top and bottom of the dryer. Using 3/4” x 3/4” stock I cut 4 pieces to a length of 24” and 4 pieces to a length of 3”. I notched out each end of the stock to create a lap joint. I then assembled the frames using glue and a brad to hold them in place while the glue dried. Once dried, I covered the frames with a nonmetallic mesh screen, which I purchased at the local hardware store. Here I also used non–rusting staples to attach the screen to the frames. For the back of the dryer I used 1/4” plywood cut to 39” x 24”. Next I cut 4 pieces of 3/4”stock to 1 1/2” x 24”.
Assembly consists of first gluing and nailing the back to the sides. I then attached the 1 1/2” pieces to the top and bottom of the back using finishing nails. Flipping the dryer over I attached the remaining 1 3/4” pieces to the top and bottom of the two sides using the same method. At this point the top and bottom screen frames can be attached to the dryer using finishing nails or screws.
The door of the dryer is constructed of two pieces of 3/4” x 1 1/2”by 36” stock and two pieces of 3/4” x 1 1/2” by 24” stock. A 22 1/2” x 34 1/2” piece of 1/8” Plexiglas fits into a 3/8” deep by 1/2” wide rabbet cut in the back of the doorframe pieces. I used 3” wood screws to assemble the frame. The Plexiglas is held in place with a 1/4”quarter–round molding, mitered to fit the frame. The finished door is mounted to the dryer using two 2 1/2”butt hinges. At the top of the dryer frame I attached two double-wing flush clips.
There are eight drying racks and they are constructed of 3/4” x 3/4” stock, 21” long and 4” wide and covered with the same nonmetallic screen. The racks sit in the grooves in the dryer’s interior and can be inserted or removed as you need.
For the back legs I used 2 pieces of 3/4” x 1 1/2” x 18” stock for the legs and 1 piece of 3/4” x 3” x 21” for the middle brace. I used 3” wood screws to fasten the legs and middle brace together. I also attached a 3/4 ” x 3” x 4” piece of stock to the back of the dryer below the leg assembly to mount the double wing flush clip. The leg assembly is attached to the dryer using strap hinges (see detail below).
To help reflect the sun I painted the interior of my dryer with white milk paint, since the idea is to dry the food not cook it. The final touch was to install a handle on the side.
To use the dryer all you need to do is set it up facing the sun and arrange your food on the drying racks. I like to slice the vegetables and mushrooms thinly as I find this aids the drying time. The great thing about this solar dryer is that it’s easy to transport, set up, easy to use, and easy to store.