Conduction is a process by which heat is transferred from the hot area of a solid object to the cool area of a solid object by the collisions of particles.
On previous pages of this lesson, we have learned that heat is a form of energy transfer from a high temperature location to a low temperature location. The three main methods of heat transfer - conduction, convection and radiation - were discussed in detail on the previous page. Now we will investigate the topic of the rate of heat transfer. This topic is of great importance because of the frequent need to either increase or decrease the rate at which heat flows between two locations. For instance, those of us who live in colder winter climates are in constant pursuit of methods of keeping our homes warm without spending too much money. Heat escapes from higher temperature homes to the lower temperature outdoors through walls, ceilings, windows and doors. We make efforts to reduce this heat loss by adding better insulation to walls and attics, caulking windows and doors, and buying high efficiency windows and doors. As another example, consider electricity generation. Household electricity is most frequently manufactured by using fossil fuels or nuclear fuels. The method involves generating heat in a reactor. The heat is transferred to water and the water carries the heat to a steam turbine (or other type of electrical generator) where the electricity is produced. The challenge is to efficiently transfer the heat to the water and to the steam turbine with as little loss as possible. Attention must be given to increasing heat transfer rates in the reactor and in the turbine and decreasing heat transfer rates in the pipes between the reactor and the turbine