Applications of Thermal Conductivity

Everyday design choices exploit thermal conductivity directly. Cooking utensils are made of a metal (a good conductor, so heat from the flame quickly reaches the food) but are fitted with handles of a bad conductor -- wood, ebonite, and similar materials -- so that heat does not readily conduct through to burn the hand holding it. Cold-storage rooms use thick brick walls (brick being a poor conductor) to slow the inward flow of heat from the warmer surroundings; using HOLLOW bricks improves this further, since the trapped air inside them is an even poorer conductor than the brick itself. To keep ice from melting quickly, it is wrapped in a gunny bag -- a poor conductor whose woven fabric also traps air (itself a very poor conductor) in its interstices, further slowing heat flow inward. …