HEAT TRANSFER FROM FINNED SURFACES

1) The rate of heat transfer from a surface at a temperature  to the surrounding medium at is given by Newton’s law of cooling as

a)  are fixed by design considerations

b) Hence there are two ways to increase the heat transfer to increase the convection heat transfer coefficient h or to increase the surface area A_s

i) Increasing h may require the installation of a pump or fan, or replacing the existing one with a larger one, but this approach may or may not be practical. Besides, it may not be adequate.

ii) The alternative is to increase the surface area by attaching to the surface extended surfaces called fins made of highly conductive materials such as aluminum.