Thermosiphon Solar Air Heater with heat storage

This is a solar air heater that uses the sun's heat to pump air into the house. It also stores heat into a bed of rock. Even after the sun sets, the heat from the rocks will still cause the thermosiphon effect to continue to work. After the sun sets, an insulated cover should be placed over the solar collector. Cheap double pane tempered safety glass can be found for free or really cheap at a glass shop. Just ask for used sliding glass doors. If they have moisture between the layers then that is easily fixed. When the glass heats up in the sun, it will steam the moisture out. You can then re silicone the edges between the glass sheets. I can pick these doors up for $20 each from the local glass shop. They told me any glass sitting outside is there to be thrown out so I can have that stuff for free.

For the inside of the solar collector, just use corrugated sheet metal roofing. Just sandwich two pieces and screw together. This forms chanels and gives more surface area for heat transfer. Paint the side facing the sun with high temp flat black spray paint. They sell that paint for barbeques.