Architectural glass light in industrial factories. Annealed glass is glass without internal stresses caused by heat treatment, i.e., rapid cooling, or by toughening or heat strengthening. Glass becomes annealed if it is heated above a transition point then allowed to cool slowly, without being quenched. Float glass is annealed during the process of manufacture. However, most toughened glass is made from float glass that has been specially heat-treated. Annealed glass breaks into large, jagged shards that can cause serious injury and is considered a hazard in architectural applications. Building codes in many parts of the world restrict the use of annealed glass
Building insulation cavities like the attic. This is beneficial in an actively cooled or heated building, but can be a liability in a passively cooled building; adequate provisions for cooling by ventilation or radiation are needed. Fibrous materials are made by tiny diameter fibers which evenly distribute the airspace. The commonly used materials are silica, glass, rock wool, and slag wool. Glass fiber and mineral wool are two insulation materials that are most widely used in this type. Cellular insulation is composed of small cells which are separated from each other. The commonly cellular materials are glass and foamed plastic like polystyrene,