Cardboard Solar Dehydrator

As summer is approaching and temperatures are soaring it is an ideal time to use a solar dehydrator to preserve produce. Through this instructable, you will learn to make your own dehydrator with supplies you probably already have at home. Fast, affordable, and easy to make!

It has two main parts, a solar collector where high temperature is harnessed from solar energy and a dehydrator part with trays inside. The main goal in such food preservation is evaporating as much moisture from it using higher temperatures and good airflow. The heat inside collector rises through a dehydrator that has vents at bottom and top allowing mositure to escape, thus drying the goods inside. You can dry herbs, food, mushrooms and vegetables.

Materials used:

• Cardboard and/or carboard boxes
• Cardboard tube
• Tape
• Transparent foil
• Glue
• Fine mesh
• Wooden stick
• Black spray paint

Tools used:

• Utility knife
• Scissors
• Measuring tape
• Ruler
• Pen
• Stapler gun

The working principle of this part is a transparent foil that lets sun heat pass through but doesn't let it escape. Heat is absorbed on a black surface and rises to the dehydrator.

I made mine out of a cardboard box as it is easier and all I had to do was cut down the height of the box to about 15cm high and add a black cardboard piece on the back of it.

Tape the box seams to make it stronger.

Cutt out the bottom vent and tape the mesh over it.

Collector is positioned at an angle to absorb solar energy better and channel the heat upward.

For this part, you want the box that is the same width as the collector part but a bit smaller in height and length. Tape the seams together and cut out the part that will be the doors of the dehydrator. Attach the door using tape from both sides to act as a hinge. To close the doors I used two magnets, but you can use velcro tape or other means.

Add a cardboard tube as support on the bottom side. A smaller box can be used as well for this purpose. The height of the support has to match the angle on the collector part.

Once you have everything set, cut out the port where the collector and dehydrator box will be joined.

One, more port needs to be cut. That port will be a top vent so it is necessary to add mesh to prevent insects from entering.

Few wooden sticks are needed as tray supports inside the box. I used the stapler gun to add them from both sides.

Before joining, I painted mine with spray paint.

The tray can be made from cardboard, here I used three-ply and it worked fine. Maybe, in retrospect, it is better to use wood or plastic to make the frame.

Cut the cardboard pieces a bit smaller than the inside of the dehydrator box. Cut the middle part out leaving about a 2-3 or 1-inch border around where you attach the fine mesh. Use staples,glue or tape to attach the mesh.

Next step is to join two parts. Start by taping the bottom edge of the collector part to the bottom edge of the box. Tape from both sides to make strong seam, then join the two sides together.

Last step is to add the foil, Cut the foil just a bitt bigger than the collector and tape it to the collector edges.

Try to get the foil as flat as possible and you can then paint the rest of it if you will.

Depending on the weather conditions and water content of the things you try to dehydrate it can take just a few hours up to a couple of days. For now, I used it to dry herbs, but as soon as fruit and vegetables are ready to be harvested I will dry those. Some fruits need to be covered in a bit of lemon juice to prevent them from discoloring such as apples and bananas. You will know goods are dry once they are brittle and hard to the touch.

Hope you liked this project. It was easy quick and cheap. Make it as big or as small as you want.

Cardboard is a great material for this as it is light, strong, and a great thermal isolator.

Have fun!