LYDON OVEN UNIVERSITY
Sophomore Curriculum

Heat In Motion

CONVECTION: The transfer of heat through a fluid (liquid or gas) by the motion of its cooler and warmer parts mixing. For instance: The motion of air caused by a difference or gradient of heat. Absent other motion, warmer air is buoyant in colder air due to a difference in density. The motion and the temperature gradient between warm and cold air transfers heat from warmer to cooler by mixing more than by conduction. “Natural convection” or “gravity convection” are often used to differentiate this convection versus “forced convection”. Forced convection is the motion of air mechanically propelled and mixed. Most Lydon Ovens use forced convection to replace cool air in contact with the object with air that is warmer than the object.

CONDUCTION: The transfer of heat energy through a single mass, or between separate masses in contact. The warmer part loses energy and the cooler part gains energy.

RADIATION: The transfer of heat energy from a hot body to a cool body that is not in contact. An example is solar energy.

TEMPERATURE: An index of the heat content of a known mass related to a “scale” or graded index. Temperature has been called “the window through which we view heat content of a known mass” because it is not strictly a measure of heat such as a calorie, kilocalorie or BTU (British Thermal Unit).

CALORIE: The quantity of heat that raises one gram of water by one degree Celsius at one atmosphere.

BTU: The British Thermal Unit is quantity of heat that raises one pound of water by one degree Fahrenheit at one atmosphere.

SPECIFIC HEAT: The specific heat of a substance is the amount of heat necessary to increase the temperature of one unit weight by one unit degree given either constant volume or constant pressure. Specific heat may be used to estimate the amount of heat the oven must supply to warm your materials to the temperature you desire. Lydon determines the amount of heat your oven needs by your process temperature, the mass of each substance and the specific heats of the substances to be heated.

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