Armstrong World Industries EHU-704 User Manual

Page of 40
6)   WATER FILL SUPPLY
Connect the unit to the building water supply (25 to 125 psig pressure). Install a shut-off valve 
near the humidifier. Connect the water supply to the 3/8" tube compression fitting on the fill valve
adaptor.
NOTE: 
ORDINARY (POTABLE) TAP WATER IS RECOMMENDED. IF POTABLE WATER IS NOT
AVAILABLE, CONSULT THE FACTORY (SEE "WATER QUALITY AND TREATMENT SECTION OF
THIS MANUAL, PAGE 23, FOR MORE INFORMATION). DO NOT USE BRACKISH OR CONTAMI-
NATED WATER.
7) CONNECT 
DRAIN
Connect to a suitable waste draining 
system. Use the clear drain hose provided 
and a 1" copper pipe (Figure 7-1), pitched 
1"per foot. The drain water may be as hot 
as 160°F. Drain it where it will not present a 
hazard to personnel. An air gap to prevent 
backflow is required if drain water is
required to be less than 140°F, use 
of Temp-R-Drain will be required.
8) INSTALL THE 
STEAM 
DISPERSION TUBE NOTE: Please 
contact factory for duct applications 
offering high static pressures (>4"WC).
a.    Verify that the proper length and type of 
steam dispersion tube has been selected: 
See Chart 7-1 for proper dispersion tube
lengths. The low capacity dispersion 
tube (Figure 7-2) is sloped toward the 
generator to allow for gravity drainage. 
On applications where the humidifier output
capacity is greater than 40 Ibs/hr, a high 
capacity tube with a ½"O.D. drain tube 
must be used (Figure 7-3). Drain tube must 
have minimum 6" water seal (see Fig. 8-3).
b.    Select a location on the duct that provides
adequate length for vapor mixing and the
shortest connection length for vapor
mixing and the shortest connection length 
to the humidifier. Preferably the location 
should be 6" downstream and/or 10 feet    
upstream from any dampers, vanes, bends
in the duct, or controllers (i.e. high limit stat).
See page 10 for details. Do not install the 
dispersion tube into ducts in which airflow 
exceeds 2,000 fpm. Do not restrict airflow in 
ducts with a depth of 8 inches or less. 
Avoid placing manifold in downward, high 
velocity air flow as dynamic air pressure will
restrict steam flow.
7
1" I.D. Clear Hose
Supplied with Unit
Fit Hose Inside
1-1/2" Pipe
1" or Larger 
Copper Pipe
L
For Steam Capacity
40 lb/hr or Less
5.25
6.00
6.00
Ø
.22 
4 Places
5.25
Ø
1.75 
Hole in Duct
6.00
6.00
R.88
3.50
1.50
Ø
.22
4 Places
1.00
5.25
R.37
5.25
2.00
3.50
For Steam Capacity
Above 40 lb/hr
Hole in Duct
L
Figure 7-1
Chart 7-1. Selecting Proper Steam Dispersion Tube
Steam
Steam Disp. 
Duct Width
Weight
Disp. Tube
Tube Length
Min.
Max.
Model No.
in
mm
in
mm
in
mm
lb
kg
D-1
12
304
11
279
16
406
3
1.4
D-1.5
18
457
17
432
22
559
3
1.4
D-2
24
609
23
584
34
864
4
2
D-3
36
914
35
889
46
1168
6
3
D-4
48
1219
47
1194
58
1473
8
3.6
D-5
60
1524
59
1499
70
1778
9
4
D-6
72
1829
71
1803
82
2083
10
4.5
D-7
84
2133
83
2108
94
2388
11
5
D-8
96
2438
95
2413
106
2693
12
5.5
D-9
108
2743
107
2718
118
2998
13
6
D-10
120
3048
119
3023
130
3302
14
6.4
Figure 7-2
Figure 7-3