Warm wall of heavy chamotte concrete blocks. Blocks 12 pieces, inside them there are already moves for the movement of gases. Blocks are easy to assemble and hold heat for 12 hours. Finishing can be any. The block itself weighs 40 kg, its size is 30 by 30 cm. I used a French-made fireplace made of cast iron, this structure heats 200 square meters, burns from 8 am to 8 pm.
