Cross-sectional area of insulation

Symbol
$A_{ins}$
Unit
mm$^2$
Formulae
$\frac{\pi \left(D_{ins}^{2} - d_{c}^{2}\right)}{4}$cable
$\frac{\pi \left(d_{ins}^{2} - do_{pipe}^{2}\right)}{4}$heat source
$do_{pipe}$
Used in
$Q_{i}$