Temperature increase of air

This is the temperature rise of the air inside an air-filled trough or channel.

Symbol
$\Delta \theta_{air}$
Unit
K
Formulae
$T_{tr} W_{sum}$in trough
$\left(T_e+T_{at}\right) W_{sum}$in channel (Heinhold)
$\left(\frac{1}{2} T_{4pi}+T_{4pii}+T_{4piii}\right) W_{sum}+\Delta \theta_p$in air-filled pipe with objects
Used in