Friday, October 14, 2011

Methods of Heat Transfer

Heat travels from warmer areas to colder areas through three modes of heat transfer: conduction, convection, and radiation. Conduction transfers heat by physical contact, as warmer molecules shift their energy to colder ones. Convective heat transfer occurs in fluids (liquids and gases), such as air. Warmer air is less dense than cooler air and rises above it. The cycle operates continuously and creates convection currents. In radiation, waves of heat energy travel through space from a warmer surface to a colder surface. Radiation occurs on a daily basis whenever anyone feels the rays of the sun.

Forced air and baseboard heating systems take advantage of convective currents. Systems with radiators or in-floor tubing (radiant heat) primarily use radiation. See for heating products for any type of heating system.