How Does Ice in a Cooler Stay Cold?
How Heat Moves In order to melt, ice needs to absorb heat. Heat is transferred in three ways: through conduction, convection and radiation. Only the first two are important in understanding how a cooler works. Conduction is when heat spreads from one object to other objects which are physically touching. The molecules of the hotter object are moving faster, and when they bump into adjacent molecules they transfer some of their heat energy. Convection is heat that moves through air currents. A stream of air moving past a warm object will continuously transfer heat away as it passes. Similarly, a stream of air moving past a cold object will transfer heat into it. Minimizing Conduction The cooler minimizes conduction by using insulators. Insulators are materials they do not conduct heat very well. Most coolers use Styrofoam as an insulator. Styrofoam has small pockets of air trapped inside of it. Gasses such as the ones that make up air have low density, which makes them poor conductors.
