Lust CDA3000 - Heat Transfer by Heat Conductance

Engineering Guide CDA3000
7-7
7 System installation
DE
EN
1
2
3
4
5
6
7
A
7.2 Heat transfer
by heat
conductance
When a constant flow of heat P flows through a flat wall, the temperatures
ϑ
1
and ϑ
2
are produced on the two surfaces (Figure 7.3). The relati-
onship is described in the equation
(1)
P: Heat flow W
λ: Thermal conductivity
A: Area of wall m²
d: Thickness of wall m
ϑ
1
, ϑ
2
: Surface temperatures °C or K
Figure 7.3 Stationary heat conductance through a wall
The thermal conductivity λ is a temperature-dependent material property.
In electronic devices it can be considered as constant for most applica-
tions. Tabelle 7.2 summarizes λ values for a number of key materials.
Depending on the task at hand - provision of good heat conductance or
high insulation - materials with the corresponding thermal conductivity are
selected.
P λ
A
d
---
ϑ
1
ϑ
2
–()=
W
mK⋅
-----------