29
STEAM INJECTION INSTALLATION, OPERATION, AND MAINTENANCE MANUAL
NOTE: For Maxi-bank option, follow the “Maxi-bank option field
assembly and installation” instructions on Page 36.
1. Insert a support bolt in one of the three holes (upper, lower
or end) of the support brackets; cut holes in duct for inserting
dispersion tube and support bolt.
2. Secure unit in duct with nuts and support bolts. Mount two-piece
escutcheon plate around each tube and secure into duct with
sheet metal screws. Where an airtight seal is required, use a
suitable caulk around duct wall penetrations.
3. Install steam strainer and steam trap. Connect to steam and
condensate return mains. See the drawings on the following
pages and text on the next for detailed piping instructions.
4. Install control tubing (pneumatic) or wiring (electric) to valve
actuator.
5. Install an airflow proving switch to prevent the valve from opening
unless air is moving in duct. See “Humidifier placement” on Pages
6 – 8 for location recommendations.
6. Install a duct-mounted high-limit humidistat downstream from the
humidifier. Set humidistat at 80-90% RH to prevent condensation
forming in duct. Mount this humidistat far enough downstream to
ensure that injected steam has been completely absorbed before
the humidistat. See “Humidifier placement” on Pages 6 – 8
for location recommendations.
7. Install a temperature switch to prevent possible cold-start
dripping when steam pressure to the humidifier is cycled.
See “Temperature switches” on Pages 16 – 19 for more
information.
8. Install the humidistat and/or sensors according to the
Installation
MULTIPLE-TUBE HUMIDIFIER
Table 29-1:
Multiple-tube humidifier minimum tube spacing
Tube
model
Minimum tube spacing (X*)
Multiple-tube humidifier
Minimum tube spacing (X*)
Multiple-tube humidifier with op-
tional stainless steel piping
inches
mm
inches
mm
60
6
152
9
229
70
9
229
9
229
80
9
229
12
305
* See Multiple-tube humidifier drawings on the following pages for center-to-
center distance X.
mc_040710_1030
For more installation information
• See “Humidifier placement” on Pages
6 – 8 for information about choosing
an installation location.
• See “Sensor placement” on Page 9.
• See “Pressurized steam piping guidelines” on
• See “Temperature switches” on Pages
• See the Maxi-bank option beginning on Page
WARNING
Excessive moisture hazard
DriSteem strongly recommends installing
a duct airflow proving switch and a duct
high limit humidistat. These devices prevent
a humidifier from making steam when
there is low airflow in the duct or when the
RH level in the duct is too high. Failure to
install these devices can result in excessive
moisture in the duct, which can cause
bacteria and mold growth or dripping
through the duct.
mc_060310_0725
WARNING
Improper mounting hazard
Mount humidifier per the instructions in this
manual and to a structurally stable surface.
Improper humidifier mounting can cause
the humidifier to fall resulting in severe
personal injury or death.
mc_060310_0725
