Data Sheet

Technical System Catalogue/Climate control
Enclosure heaters
3 - 82
Project planning
Enclosure heaters
The required thermal output is calculated from:
Heating performance diagram
Q
H
= Thermal output (W)
A = Enclosure surface area to IEC 890 (m
2
)
ΔT = Temperature difference (K)
Based on:
Interior siting, static air,
heat transfer coefficient k = 5.5 W/m
2
K
For exterior siting (moving air):
Double the determined thermal output
Q
H
= A  ΔT  k
.
A
ΔT
1
1.5
2
3
4
5
6
8
10
15
30 50
150 300 500
10
20 40 60
80 100 200
20
30
2
5
7.5
10
15
Q
H
.
.
Even temperature distribution
Via a CFD analysis, even temperature distri-
bution in the (empty) enclosure is observed
when using a 400 W enclosure heater fol-
lowing a heating period of approx.
30 minutes.
According to the CFD analysis, positioning
of the enclosure heater in the base area of
the enclosure is essential for even tempera-
ture control of the enclosure, since those
areas located beneath the heater are only
minimally warmed.
25.0000
Te mp erature °C
22.5000
20.0000
17.5000
15.0000
12.5000
10.0000
7.50000
5.00000
Start After 5 minutes
After 15 minutes After 30 minutes