heatwhere

Heatwhere is a term used in discussions of heat transfer to denote the spatial locus where heat exchange with a system is assumed to occur. It is not a standard physical quantity but a descriptive label that helps distinguish where heat input or output is applied in a model or experiment. In practice, heatwhere identifies the boundary, interface, or region responsible for thermal interaction with the surroundings or within the object.

In mathematical models, heatwhere often corresponds to a boundary or interface in which boundary conditions are specified. For example, in a conduction problem, the heatwhere may be the surface where a prescribed heat flux q'' is imposed (Neumann condition) or a surface held at a fixed temperature (Dirichlet condition). In radiative or convective problems, the heatwhere can denote the interacting surface or region where the environment exchanges energy with the object.

Examples include a heated metal plate with the heater attached to its bottom surface, which defines a heatwhere at that interface; the inner wall of a furnace during operation; or the boundary between a warm room and the outside environment in a building heat transfer analysis.

Because heatwhere is not a standard term, its meaning can be ambiguous in complex geometries or distributed sources. It is primarily a pedagogical and modeling aid to localize where heat transfer is applied rather than a measurable quantity, and problems may involve multiple heatwheres.

See also heat transfer, boundary condition, heat flux, thermal analysis.