Parameter · 05 Boundary Conditions

Insulation conductivity

wall.thermal.insulation.k Unit: W/(m K) Step 05 · Boundary Conditions

The thermal conductivity of the insulation wrap. Used only when the insulation thickness is above 0.

Last updated 2026-11-03

Theory

The insulation is the second planar layer of a heat-loss wall; its resistance is $t_{ins}/k_{ins}$ and adds to the shell's.

R_{ins} = \frac{t_{ins}}{k_{ins}}

(1)

where	meaning	unit
$R_{ins}$	Insulation resistance per unit area	m² K/W
$t_{ins}$	Insulation thickness	m
$k_{ins}$	Insulation conductivity (this setting)	W/(m K)

Default: 0.06 W/(m K)
Rule: 0.06 W/(m K), the wall-material library's insulation-wrap value (range 0.05-0.08).
Source: The default is the program's design value for an insulation wrap; it is not taken from a cited handbook.

Constant

Real insulation conducts more when hot; use a value for the mean temperature of the wrap.