I have been kicking around the idea of building a sort of kiln like box made from possibly fire brick and clay or some other better type of high temp tolerant material and insulated with a thick layer of dirt. It would be built in a way which would allow air to be drawn through it and heated to a very high temperature with a large Fresnel lens as the top of the box. The air would then be pumped through a large mass inside a tiny house and then on into the house itself. The air flow could be generated by a small exhaust fan at the end of the pipe inside the home. does anyone have any thoughts on whether this might work, how efficiently it might work, best possible building materials, ect... any thoughts are welcome