# Total Heat Transfer

on . Posted in Thermodynamics

Total heat transfer, abbreviated as Q, is the heat put into a system or heat lost from a system.  It represents the total amount of heat energy transferred between two systems or bodies.  It is a measure that includes Conduction, Convection, and Radiation, depending on the specific context.

In various engineering and physics applications, you may encounter specific equations for each mode of heat transfer, and the total heat transfer is the sum of these contributions.  It's essential to consider all relevant modes of heat transfer when analyzing or designing systems to ensure an accurate assessment of the total heat transfer.

### Total Heat Transfer Formula

$$Q \;=\; h \; A \; ( T_s - T_{\infty} )$$     (Total Heat Transfer)

$$h \;=\; Q \;/\; A \; ( T_s - T_{\infty} )$$

$$A \;=\; Q \;/\; h \; ( T_s - T_{\infty} )$$

$$T_s \;=\; ( Q \;/\; A \; h) + T_{\infty}$$

$$T_{\infty} \;=\; T_s - ( Q \;/\; A \; h)$$

Symbol English Metric
$$\large{ Q }$$ = total heat transfer $$Btu\;/\;hr$$ $$W$$
$$\large{ h }$$ = heat transfer coefficient $$Btu\;/\;hr-ft^2-F$$ $$W\;/\;m^2-K$$
$$\large{ A }$$ = surface area where heat is transfered $$ft^2$$ $$m^2$$
$$\large{ T_s }$$ = surface temperature $$F$$ $$K$$
$$\large{ T_{\infty} }$$ = approach fluid temperature $$F$$ $$K$$