# Heat Flow Calculation

Formula

Calculated Heat Flow = (Conductivity of Material*Area(ft2)*(Temperature of
Hot Surface(F)-Temperature of Cold Surface(F))/Thickness(inches))

Heat Flow refers to the movement of heat from one body to another like gas, liquid, solid, or any of the combinations thereof by means of radiation, convection, or conduction. Heat Flow is defined as the energy that is in transit due to temperature difference. Heat Flow is also called as heat transfer, heat exchange, or transfer of thermal energy. The larger the temperature gradient, the higher the rate of heat transfer.

Heat Flow is occurred when there is existence of temperature difference in a medium or between media. The basic requirement for heat transfer is the presence of temperature difference.

Example:
Calculate the Heat Flow for the given details.
Temperature of Hot Surface (F) = 5
Temperature of Cold Surface (F) = 2
Conductivity of Material Btu-in./(h�ft2��F) = 3
Area (ft2) = 4
Thickness (inches) = 10

Solution:
Apply Formula:
Calculated Heat Flow= (Conductivity of Material*Area (ft2)*(Temperature of Hot Surface (F)-Temperature of Cold Surface(F))/Thickness(inches))
Calculated Heat Flow = (3*4*5-2)/10
Calculated Heat Flow = 12*3/10
Calculated Heat Flow = 36/10
Calculated Heat Flow = 3.600 (Btu/h)