Fiberglass is a type of fiber primarily composed of glass that is used in a wide variety of applications, and is predominantly employed as a residential and commercial thermal insulator. Fiberglass is also used to create products as varied as automobile bodies, boat hulls, arrows, roofing, shower curtains, and tent poles.
As an insulator, it slows the spread of heat, cold, and sound in structures, cars and aircraft. By trapping pockets of air, it keeps rooms warm in the winter and cool in the summer and thereby serves as a convenient method to increase energy efficiency.
Fiberglass is an attractive choice for home insulation because it poses no fire hazard. According to some estimates, thermal insulation (made from fiberglass and its alternatives) conserves 12 times as much energy as is lost in its production, and it may reduce residential energy costs by up to 40%.