# Heat removed by air at z

Heat removed by the air in the tunnel at the point z in the cable route, which is equal to $C_{av}\frac{\partial{\theta_{at}(z)}}{\partial{z}}$.

Symbol
$W_{a,z}$
Unit
W/m
Formulae
$\frac{\left(T_t+T_e\right) N_{sys} N_c W_{tot}-\theta_{at,z}-\theta_a}{T_a+T_t+T_e}$
Related
$T_a$
$T_e$
$T_t$
$\theta_a$
$\theta_{at,z}$
$W_{tot}$
Used in
$\theta_{o,z}$
$\theta_{t,z}$