CAUTION
Each humidifier requires its own steam hose and dispersion tube. Do not connect steam hoses from more than one humidifier
together. Back-pressure from one humidifier can lower the water level in the canister in the other humidifier and cause
operational problems.
Do not install the dispersion tube in a duct with greater than 2 in. wg static pressure. High duct pressure can cause back-
pressure in the canister which can result in unstable unit operation.
TABLE 3 – Absorption Distance (Minimum distance from dispersion tube downstream to any obstruction or bend in duct)
Humidifier
Output (gal/day) Airflow Velocity*
70°F & 30% RH
Setpoint
70°F & 45% RH
Setpoint
65°F & 45% RH
Setpoint
45°F & 45% RH
Setpoint
Up to 16 .0
300 fpm
13”
19”
23”
30”
600 fpm
6”
10”
12”
18”
1200 fpm
3”
5”
6”
13”
1800 fpm
2”
3”
4”
10”
20 .5 – 25 .0
300 fpm
15”
23”
28”
45”
600 fpm
6”
12”
13”
26”
1200 fpm
5”
6”
7”
19”
1800 fpm
3”
4”
5”
16”
25 .0 – 35 .0
300 fpm
24”
31”
36”
60”
600 fpm
17”
22”
26”
48”
1200 fpm
12”
15”
18”
25”
1800 fpm
10”
13”
15”
20”
*Velocity in feet per minute = Duct airflow volume in cubic feet per minute / duct area in square feet .
Example: 1,200 cfm through 16” x 12” duct = 1,200/(12 x 16/144 sq . in ./sq ft .) = 1,200/1 .333 = 900 fpm
INSTALLATION INSTRUCTIONS
(CONTINUED)
ELEVATION
The preferred location for the dispersion tube is higher than the
humidifier so that the steam hose has a constant downward slope of at
least 2” per foot from the dispersion tube to the humidifier . If hard pipe
is used, the slope can be 1/4” per foot . With the constant downward
slope, any condensation that forms in the steam hose will drain back
into the steam canister . See
Figure 3
.
FIGURE 3 – Dispersion Tube Mounted Above Humidifier
90-1704
90° long sweep
or two 45° elbows
Pitch*
Duct
Dispersion
tube
5” minimum
Steam hose or pipe.
Insulate pipe with 1” fiberglass
to reduce steam loss.
* Pitch steam hose down
from dispersion tube to
humidifier:
2”/ft (15%) minimum
when using steam hose.
1/4”/ft when using
hard pipe.
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