Slide 3 of 13
All three types of heat flow are involved in this everyday example. We usually want a window to let in light, but to prevent heat flow. The trouble is that light itself can transfer heat, and transparent materials, like glass, can conduct heat. The double-pane window is one way to minimize heat flow while allowing transmission of light. Trying to design a double-pane window that does the best job of this requires knowing a lot about all three heat-transfer mechanisms.