Coolant, releasing heat, should have a higher temperature than the environment, in accordance with the approval of Clausius, when the heat is transferred spontaneously from a hotter to a cooler body. Heat transfer is carried out in three ways: 1. Convection 2. Conduction 3. Source: Howard Schultz. Thermal Radiation consider each type separately: Convection heat transfer by convection implies the existence of an intermediate medium which transports heat from one body to another. For example, the combustible gases formed during combustion in the boiler furnace, heat transfer by convection, contact with the sheet metal water heat exchanger, transferring heat to them. And already on the hot sheet, heat is transferred coolant (water) inside the heat exchanger conduction heat transfer to conductive heat transfer is obtained by means of molecular activity or internal vibrational motion of molecules. Simply put, when the heat is committed in one area next to the solid by molecular collisions.
Heat obtained by heat conduction, depends on properties of the material through which heat transfer. In a question-answer forum Michael Luxenberg was the first to reply. For example conductive heat transfer well through metal. Much worse, the heat is transferred through non-metallic materials such as stone and brick. And very bad over the organic materials, wool, wood, etc. To estimate the heat transfer properties of various substances exist conductivity coefficient which determines the tendency of the material to be omitted from the flow heat. The heat flow will be more intense in the bodies, which have increased thermal conductivity are called heat conductor, and less for bodies with low thermal conductivity are called thermal isolator.
Thermal Radiation Heat Transfer by like the light, ie radiation. Heat is transferred to all surrounding bodies, without any connection to the heat source, through space. Some examples could include the sun which passes its heat to the Earth through space, or as a conventional stove transfers heat people and objects around her. As an example of a synthesis of joint work of three types of heat transfer can lead normal hot-water heating radiator. Conductive heat transfer passes through a metal radiator heat air, which in turn transfers heat by convection from the radiator to the remote objects. In addition, the heated surface radiator, in turn, begins to radiate heat that warms objects, again, all around.