24
The calculation of the humidification distance “B
n
” is dependent on several
factors. For a rough estimation of the humidification distance “B
n
”, the fol-
lowing table is useful. Recommended standard values listed in this table
are based on a supplyair temperature range of 15 °C to 30 °C.
Humidity at inlet
ϕ
1 in %rh
Length of humidification distance B
N
in m
Humidity at outlet
ϕ
2 in %rh
40
50
60
70
80
90
5
0.9
1.1
1.4
1.8
2.3
3.5
10
0.8
1.0
1.3
1.7
2.2
3.4
20
0.7
0.9
)
1.2
1.5
2.1
3.2
30
0.5
0.8
1.0
1.4
1.9
2.9
40
–
0.5
0.8
1.2
1.7
2.7
50
–
–
0.5
1.0
1.5
2.4
60
–
–
–
0.7
1.2
2.1
70
–
–
–
–
0.8
1.7
φ1 in %rh: Relative supply air humidity prior to humidification at the lowest supply air tem-
perature
φ2 in %rh: Relative supply air humidity after the steam distribution pipe at maximum capacity
Example
given:
ϕ
1= 30 %rh,
ϕ
2= 70 %rh
humidification distance B
n
: 1,4 m
4.4.2
Positioning of the steam distributors in a duct
The location for the steam distributor in the duct should be determined at the
time of dimensioning the air conditioning system. Please note the following
instructions to ensure proper humidification of the duct air.
Calculating the humidification distance
The water vapour, emitting from the steam distributors, requires a certain
distance to be absorbed by the ambient air so that it is no longer visible as
steam. this distance is referred to as
humidification distance “B
N
”
and
serves as a basis for the determination of the minimum distances from the
upstream components in the system.
B
N
: Humidification distance B
n
E
: Expansion and mixing zone
φ
1
: Supply air humidity
before
humidification
φ
2
: Supply air humidity
after
humidification
Summary of Contents for es4 4
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