22
52002_A_EN_1611
Nortec AF-22
9.2.1.1 Calculating the maximum humidification capacity
The maximum humidification capacity is calculated using the following formula:
m
H2O
:
Maximum humidification capacity in
lb/h
V
:
Air volume to be humidified in
ft
³
(formula: L x W x H)
V
1
:
Specific volume of air at set point in
ft
³
/
lb
AE/h :
Number of air changes per hour
The number of air changes per hour depends on the usage of the room and must be determined by the system
planner as part of the planning process. The following guide values can be taken as the basis:
Textile processing: 3
– 7 AE/h
Printing works:
2
– 5 AE/h
Storerooms:
1
– 3 AE/h
Cooling rooms:
max. 1 AE/h
1.0 :
Fixed value for the specific weight of the air in
lb/ft
³
A
:
Fixed value (7,000) for the conversion of pounds to grains in
grains/lb
.
x
2
:
Desired absolute humidity of the air in the room in
grains/lb
x
1
:
Minimum absolute humidity y before humidification in
grains/lb
NOTES:
Where outside air represents 100 % of the air, the outside air condition in winter must be applied. If there is an air
circulation system (30 % outside air, 70 % recirculated air), the resulting air mix must be applied.
For the values for
x
2
and
x
1
refer to the
psychrometric chart
in the appendix.
NOTES:
The formula takes no account any absorption or discharge of humidity by materials in the humidified room.
SOLUTION EXAMPLE 1
In this example, a humidification capacity of
101 lbs/h
is required.
In case of questions regarding the calculation of the humidification capacity, please contact Nortec.
9.2.1.2 Determining the device requirements
Now the decisive value of the necessary humidification capacity is available for the determination. The
following notes on the capacity of the atomizers provide a second basis.
Capacity AF-22
(22 lbs/h)
EXAMPLE 1 (continued)
Total water volume (mH2O) =
101 lbs/h
Required:
5 units AF-22
1 unit transformer
V x 1.0 x AE/h x (X
2
– X
1
)
m
H2O
=
A x V
1