# Heat Transfer Coefficient

Written by Jerry Ratzlaff on . Posted in Thermodynamics

Heat transfer coefficient, abbreviated as h, also called film coefficient or film effectiveness, is the convective heat transfer between a solid surface and the fluid around it.

## Heat Transfer Coefficient formula

 $$\large{ h = \frac { Q" }{\Delta T} }$$

### Where:

 Units English Metric $$\large{ h }$$ = heat transfer coefficient $$\large{\frac{Btu}{hr-ft^2-F}}$$ $$\large{\frac{W}{m^2-K}}$$ $$\large{ Q" }$$ = heat flux $$\large{\frac{Btu}{hr-ft^2}}$$ $$\large{\frac{W}{m^2}}$$ $$\large{ \Delta T }$$ = temperature differential between the solid surface and surrounding area $$\large{F}$$ $$\large{K}$$

## Related Heat Transfer Coefficient formula

 $$\large{ h=\frac{ Nu \; k }{ l_c } }$$ (Nusselt number)

### Where:

$$\large{ h }$$ = heat transfer coefficient

$$\large{ l_c }$$ = characteristic length

$$\large{ Nu }$$ = Nusselt number

$$\large{ k }$$ = thermal conductivity