Installation Instructions
37Mounting and installation work
5.4.2 Positioning of the steam distributor
The location of the steam distributor should be determined at the time of dimensioning the air condition-
ing system. Please note the following instructions to ensure proper humidication of the duct air.
Calculating the absorption distance
The steam, emitting from the steam distributor, requires a certain distance to be absorbed by the air so
that it is no longer visible as steam. This distance is referred to as absorption distance "B
N
" and serves
as a basis for the determination of the minimum distances from the upstream components in the system
Fig. 16: Absorption distance "B
N
"
The calculation of the absorption distance "B
N
" is dependent on several factors. For a rough estimation
of the absorption distance "B
N
", the following table is useful. Recommended standard values listed in
this table are based on a supply-air temperature range of 15 °C to 30 °C. The values given in bold type
apply to steam distribution pipes DV81-..., the values in brackets apply to the OptiSorp steam
distribution system.
Humidity at inlet
ϕ1 in %rh
Length of absorption distance B
N
in m
Humidity at outlet ϕ2 in %rh
40 50 60 70 80 90
5 0,9 (0,22) 1,1 (0,28) 1,4 (0,36) 1,8 (0,48) 2,3 (0,66) 3,5 (1,08)
10 0,8 (0,20) 1,0 (0,26) 1,3 (0,34) 1,7 (0,45) 2,2 (0,64) 3,4 (1,04)
20 0,7 (0,16) 0,9 (0,22) 1,2 (0,30) 1,5 (0,41) 2,1 (0,58) 3,2 (0,96)
30 0,5 (0,10) 0,8 (0,17) 1,0 (0,25) 1,4 (0,36) 1,9 (0,52) 2,9 (0,88)
40 – 0,5 (0,11) 0,8 (0,20) 1,2 (0,30) 1,7 (0,45) 2,7 (0,79)
50 – – 0,5 (0,13) 1,0 (0,24) 1,5 (0,38) 2,4 (0,69)
60 – – – 0,7 (0,16) 1,2 (0,30) 2,1 (0,58)
70 – – – – 0,8 (0,20) 1,7 (0,45)
φ1 in %rh: Relative supply air humidity prior to humidication at the lowest supply air temperature
φ2 in %rh: Relative supply air humidity after the steam distribution pipe at maximum capacity
For duct widths <600 mm the absorption distance for the OptiSorp system increases by approx. 50%
φ1: Supply air humidity before humidication
φ2: Supply air humidity after humidication
Expansion and mixing zone
Absorption
distance B
N
Safety humidistat /
Humidity sensor