The majority of the radiant energy released at operational temperatures is transmitted through the thin quartz tube but some of that energy is absorbed by the silica quartz glass tube causing the temperature of the tube wall to increase, this causes the silicon-oxygen bond to radiate far infrared rays. Quartz glass heating elements were originally designed for lighting applications, but when a lamp is at full power less than 5% of the emitted energy is in the visible spectrum.Investigation of Reflective Materials for the Solar Cooker
