Masonry oven more common as accessory features of a masonry heater. A compromise design known as the gueulard in France combines aspects of both internal and external-fired models. Masonry ovens remain popular in part because of the way their use affects cooking processes and food flavor. Where modern gas or electric ovens cook food by moving hot air around inside an insulated, lightweight box, a masonry oven works by soaking up heat, like a battery building up a full charge. When hot, the heavy oven walls release the heat slowly, for hours. Thus the food is cooked not only by hot air,
Ceramic houses further research into earth architecture. Each of his projects achieved moderate publicity, but Khalili's geltaftan technology has seen little use since the 1980s. This is in part because of the pollution involved in oil firing. The Geltaftan Foundation, and Cal-Earth has since carried on experiments with ceramic housing, but Nader Khalili is most noted today for his work developing Super Adobe: an earth building technique using earth-filled bags as structural elements. The earth used for building ceramic houses is essentially a type of adobe with a higher clay content and fewer impurities. The earth and water are mixed until the