ABSORPTION
DISTANCE
SUPPLY DUCT
AIRFLOW
AS35 Steam Humidifier
Quick Start Guide
3
PITCH*
DUCT
DISPERSION
TUBE
TUBELETS
5" MINIMUM
* PITCH STEAM HOSE DOWN
FROM DISPERSION TUBE
TO HUMIDIFIER:
2"/FT (15%) MINIMUM
WHEN USING STEAM HOSE.
1/4"/FT WHEN USING
HARD PIPE.
STEAM HOSE OR PIPE.
INSULATE PIPE WITH
1" FIBERGLASS
TO REDUCE
STEAM LOSS.
90° LONG
SWEEP OR TWO
45° ELBOWS
90-2510
2
90-1521
Choose a location in a
conditioned space
Place outside the grow room if possible. The capacity of the
humidifier is reduced by the length of the steam hose or pipe due
to condensation. The maximum recommended length of steam
hose is 6 feet. Use hard pipe insulated with 1" thick insulation
rated for 212°F or higher for lengths greater than 6 feet. If 6-foot
steam hose does not reach from humidifier to dispersion tube,
splice in 1" copper pipe using 3/4" x 1" reducing coupling.
See Installation Manual for more details.
• The steam tubelets must face up
regardless of the airflow direction
in the duct. The plate is labeled
“UP” to indicate proper orientation.
• On horizontal duct runs, install the
dispersion tube low in the duct.
On vertical duct runs, center the
tube on the duct.
NOTE:
If the dispersion tube is mounted on insulated ductwork,
make sure the insulation is not more than 2" thick at tube location.
1
Duct location and
absorption distance
Absorption distance is the unobstructed straight line distance
needed for steam to be fully absorbed.
• Determine absorption distance based on the lowest air
velocity that the system will see (refer to table below).
• Locate dispersion tube in a straight section of duct, far
enough upstream of any obstructions or bends in the duct.
ABSORPTION DISTANCE
Tonnage
per CFM
Recommended
Absorption
Distance
5 ton
2000 CFM
12 inches
10 ton
4000 CFM
6 inches
CENTER
CENTER
Install dispersion tube
1
