Heat Return
Heat return is the heat exchange between the surface of a solid body and the environment-coolant.
Heat return is based on the phenomena of natural or forced heat transfer by thermal conductivity, convection and radiation from one temperature level to a lower temperature level.
There are heat return for free and forced movement of the coolant, as well as for changes in its physical state.
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Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc