# Thermal resistivity backfill

Thermal resistivity of backfill material.

The thermal resistivity of the backfill is only relevant for the cables within this backfill area. The heat flow of cables outside of a backfill area is not influenced by the backfill, which also applies for cables in another backfill area.

Symbol
$\rho_b$
Unit
K.m/W
Used in
$R_{q11}$
$R_{q21}$
$R_{q31}$
$T_{4d}$
$T_{4db}$
$T_{4w}$