### Convective Heat Transfer Coefficient - Heat Transfer

**Heat Transfer Engineering | Thermodynamics**

The convective heat transfer coefficient (h), defines, in part, the heat transfer due to convection. The *convective heat transfer coefficient *is sometimes referred to as a film coefficient and represents the thermal resistance of a relatively stagnant layer of fluid between a heat transfer surface and the fluid medium. Common units used to measure the convective heat transfer coefficient are Btu/hr - ft^{2} - ^{o}F.

h = q / ΔT

where:

*q *: amount of heat transferred ( heat flux ), W/m^{2} i.e., thermal power per unit area , *q *= *d Q */ *dA **
h *: heat transfer coefficient, W / (m

^{2}· K)

ΔT: difference in temperature between the solid surface and surrounding fluid area, K

It is used in calculating the heat transfer , typically by convection or phase transition between a fluid and a solid. The heat transfer coefficient has SI units in watts per squared meter kelvin: W/(m^{2} K).

The heat transfer coefficient is the reciprocal of thermal insulance . This is used for building materials ( R-value ) and for clothing insulation .