# Thermal resistance 13 of multi-layer backfill

Thermal resistance of 3rd segment along flow path $\Phi_1$ of the multi-layer backfill method.

Symbol
$R_{q13}$
Unit
K.m/W
Formulae
 $\rho_{b1} \left(\frac{s_{b1}}{w_{b4}}+d_{im}\right)$ Including a top layer $\rho_{b2} d_{im}$ Without top layer
Related
$d_{im}$
$\rho_{b1}$
$\rho_{b2}$
$s_{b1}$
$w_{b4}$
Used in
$R_{CG}$