7
6
STEP 5: Determine Location for Humidifier Control
and Mount Control
Humidifier Control must be mounted on the Return Duct, at least
6 inches upstream of the following (see
Figure C
):
• Humidifier
• Humidifier Bypass Ductwork (if applicable)
• Fresh Air Intake Ductwork (if applicable)
Operating temperature of the Humidifier Control is to be from
20°F to 120°F to prevent damage to the control display.
Figure C
90-1137
6" MIN.
RETURN
DUCT
HUMIDIFIER
CONTROL
FRESH AIR
INTAKE
COIL
HUMIDIFIER
BYPASS
CONNECTION
DUCT (SHEET METAL) MOUNT:
After location for Control is selected, drill a 3/4 inch hole for the
RH sensor (the RH sensor extends from the back of the
Humidifier Control).
Use 2 sheet metal screws, 3/4 inch long (not provided), to mount
the Humidifier Control. Use the mounting slot to level the Control,
then secure the Control with the second sheet metal screw.
Make sure the Humidifier Control sensor gasket is seated tightly
around the drilled hole. Do Not Install Control Without Gasket.
Reattach cover and knob.
DUCT (FIBER BOARD) MOUNT:
After location for Control is selected, cut a rectangular hole in
the duct board, no smaller than 6-9/16 inches long by 4-3/8
inches wide.
Cut a rectangular piece of sheet metal to fit behind the hole in
duct board for mounting the Humidifier Control.
Drill a 3/4 inch hole for the RH sensor (the RH sensor extends
from the back of the Humidifier Control) into the sheet metal
plate.
Use 2 sheet metal screws, 3/4 inch long (not provided), to mount
the Humidifier Control.
Make sure the Humidifier Control sensor gasket is seated tightly
around the drilled hole. Do Not Install Control Without Gasket.
Secure the sheet metal plate, with the Humidifier Control
mounted, inside the duct (see
Figure D
). Reattach cover and knob.
CONTROL REPLACEMENT:
When replacing an existing control, the duct opening left by the
removed control must be covered completely. Locate and install
the new control as instructed previously in Step 5.
