# Convection heat transfer coefficient, duct to air

Symbol
$h_{conv_{da}}$
Unit
W/(K.m$^2$)
Formulae
 $\frac{\mathrm{Nu}_{da} k_{gas}}{L_{d}}$ natural convection (no wind) $\frac{2 \mathrm{Nu}_{da} k_{gas}}{D_{do}}$ forced convection due to wind (>0.5 m/s) $\left(h_{laminar}^{2} + h_{turbulent}^{2}\right)^{0.5}$ natural and forced convection at low wind speed (≤0.5 m/s)
Related
$D_{do}$
$k_{gas}$
$L_{d}$
$\mathrm{Nu}_{da}$
Used in
$W_{conv_{da}}$