A VERY GOOD SOLAR FOOD DRIER
The easiest and most efficient solar food drier possible made from recycled objects.
I spent many hours looking on internet for plans on how to make a solar drier. There are hundreds of different designs on pinterest and on homesteading sites. I almost started to make a couple of the most promising ones but fortunately I waited. I eventually found one that I considered to have the best concept at Elder Grove Homestead (see link below) I then realized that I already had all the materials needed to make a solar drier without buying anything and without building or constructing anything. My version uses a clear window with most of the heating happening on the bottom corrugated iron plate which generates a slow hot convectional current of air.
A piece of corrugated iron painted black.
Some metal mesh with fairly small holes wired down to panels of an old chicken run.
Some circular sand sieves. (builders use them for sieving sand)
Some old windows.
Some ground which has a slight slope.
The above photo shows the solar drier in use:
How it works.
The sun shines through the window and heats up the black corrugated iron base. The heat and air is trapped in by the glass. As the solar drier is on a slope, the hot air moves slowly upwards and then escapes from the top of the window. New air is constantly drawn in from the bottom. The food does not burn because as the temperature gets hotter the air moves faster. If it rains it is no problem the food is protected and it does not need to be brought in. The temperature is too hot for insects and even ants do not stay long.
We have two or 3 electric food driers but after a few days using this one I packed them away because this works so much better. In the hot sun of August most things were bone dry in one day. I even used this system to dry a load of comfrey leaves so that I don’t have to put up with the smell of rotting comfrey. I can just add the dried comfrey powder directly to the plants.
The main advantage is that no construction is required. If the drier is not in use you can just pick up the pieces and stack them somewhere. No electricity. No moving parts. A lot of the solar driers you see on internet have one window leading to a whole stack of food trays. Even in hot weather this must be slow. With our design the food is dried very quickly, at first you can even see the moisture condensing on the window.
If you have to buy the windows it could be quite expensive however old windows are quite easy to get hold of. Other websites say that the mesh should be made out of food grade stainless steel. This is probably correct but I think I will risk it. If you paint the corrugated iron you should probably leave it out for a few days to drive off any volatile chemicals. (I did not actually paint mine) . The builder’s sieves can be bought from any builder’s merchant alternatively you can make some wooden frames and staple mesh onto them.
As you can see we have two options of placing the food. On the sand sieves or on the mesh grids. Either work perfectly but the sieves are easier to load with produce and bring to and from the kitchen. The windows are not connected with hinges they can be lifted up with one hand while the food is slipped in with the other. If they get dirty they can be picked up and blasted with water.
The photo above are some of the dried foods on the kitchen shelf ready to be added to many dishes during the winter months. The Tsunami by the way is a failed attempt to make marmite from wine yeast. In the end I dried it out and decided that it will add some umami taste to some foods (hence the name) In the year of COVID just the two of us managed to dry a massive amount of food during the summer.
For loads of technical details and useful information go to Elder Grove Homestead You don’t need all the hinges and fancy construction techniques that they use you can just do it like mine on the floor with a few old windows.