Small Beginnings

Most solar oven cook food by concentrating sunlight. There are different designs and most of them can be fashioned in very short amount of time with cardboard boxes and aluminium foil. The Solar Oven we chose to build is the design of an Arizona based - award winning tracking solar oven design which can be found here: solarcooking.org/plans/cookerbo.pdf. It works on amalgamation of different principle like; convection i.e. warm air rises up and is replaced by cool air, greenhouse effect and concentration of solar radiation. We will be making appropriate changes to the design as required.

Theoretically, if an airtight, insulated hollow box is heated, the temperature inside the box should rise up infinitely. But we cannot totally isolate the system and some heat loss will always be prevalent regardless of the insulation. With proper shape, insulation and angle of incidence, our aim is to reach about 250°C (optimistically). We also have a challenge of spending little to no money on this project so we’re building it all out of predominantly discarded materials. Almost everything we use in this project will be trash (technically). We got the together around the end of may and spent the rest of the month on planning. Since we are only using trash, our design options are very limited. We can only build our oven according to the trash we find. Until now we have found pieces of board wood, wooden beams, an old discarded oven and window all thanks to the city of Tampere and TAMK.

Disassembly of the oven

The meat and potatoes

We have a pallet to start with as a base. Our basic design is to mount the oven into a base and fitting a window in the rear end with reflectors to concentrate the sunlight. A chamber will also be mounted between the oven and the window which will give the set-up some room for convection. We are still not quite sure about the insulation. There are few options we are thinking about. The easiest material to obtain would be the insulation (rock wool) that is used to insulate buildings. There was also the option of using the air conditioner thermal insulator. We thought that might be available to us since the school was also under renovation and we might get the extra they ones that they don’t need or the old ones they want to dispose of. For now we will continue to gather materials to design and build with.

As it stands now we have aquired the following:

an old Upo oven
a number of 4cm x 4cm lengths of wood
about 40 lengths of reclaimed fence wood that had been stained brown
a reclaimed wooden loading pallet ( this would act as our base )
a number of different screws and bolts
clamps, saws, screwdrivers, etc... many tools