Fiberglass is used inside car mufflers as a noise reducer and insulator. The insulating properties of the fiberglass eliminates the need for muffler heat shields, however to properly design vehicles without heat shields, it is important to know the thermal conductivity of fiberglass at high temperatures. A TPS Thermal Constants Analyzer was used to measure the thermal conductivity of glass fibers with diameters of 17 µm and 24 µm. Each sample was ...