1
SEQUENCE OF OPERATION
RECOMMENDED LOCATION
TEMPERATURE AND SAFETY REQUIREMENTS
HUMIDIFIER MOUTING LOCATION
Installation Instructions
Owner’s Manual
STEP BY STEP INSTALLATION
DRILL MOUNTING HOLES AND CUT OPENING
MODEL GH2500
MOUNTING HUMIDIFIER
HUMIDISTAT MOUNTING LOCATION
MODEL GH2500 SCOOP HUMIDIFIER
Refer to the rating plate on the furnace for minimum
clearances to combustible construction. All parts and
connections of a BestAir PRO humidifier must be
installed outside of the minimum clearance require-
ments for rear, top, sides, and flue of furnace. Do not
install where humidifier or water connections may be
exposed to freezing temperatures or outside weather.
Attic installations are NOT recommended.
If you have
central air conditioning, carefully plan the location of the
plenum opening to prevent damage to the cooling coil or
other components inside the duct.
The BestAir PRO model GH2500, is to be mounted on
the supply duct of the furnace only.
The BestAir PRO Model GH2500 use the evaporative
principal to add moisture to the warm air heating system.
Upon a demand for humidity from the humidity control,
the water solenoid valve opens and water flows in at the
top of the media pad and is evaporated, as warm air
passes through the media pad. When the moisture
laden air re-enters the duct it is mixed with dry air already
flowing through the duct. This moisture laden air gradu-
ally increases the relative humidity level in the home.
CAUTION
:
Installation should be performed by
qualified personnel only. Use eye protection and
gloves when drilling and handling sheet metal. All work
must be performed to local & national codes and ordi-
nances. Use multi-conductor 18 awg solid copper wire.
Provide over-current protection as required. DO NOT
omit the drain or overflow tubing.
Turn off power to the furnace before installing the
humidifier. Test fit the GH2500 housing on the side of
the warm air plenum. Before proceeding, verify that
adequate clearances are available for servicing the
media pad. There must also be adequate room (5 1/2
inches) inside the plenum for the louver. If necessary,
relocate the unit. Use a plumb line or a level to make
sure the housing is level. With a permanent marker
outline the inside edge of the housing. Also mark the
twelve holes to be drilled. Center punch and drill all
twelve holes as indicated by the marks. Drill or punch
a starter hole and then use tin snips to cut out the rect-
angular shaped opening. The opening should be 1/8
inch larger on all four sides than what was marked.
Hold the housing next to to duct and start four #8 x 3/4
inch long sheet metal screws through the holes in the
bottom edge of the humidifier. With these four screws
started the unit should remain in place while starting
the other eight screws. With all twelve of the screws
started they can now be tightened. With the housing
mounted the louver can be installed. This should be
done by rotating the louver to the proper position
depending on the direction of air flow. The air flow
should enter into the curved multi-louvers and exit out
of the large opening.
The humidistat can be mounted on the cold air return
duct to sense the cool dry air returning to the furnace. It
can also be mounted on an interior wall near the furnace
thermostat as well. The electrical connections and basic
wiring are the same for duct mounted or wall mounted
humidistats.
TB 218 Part#090375A0218-GH
12122006GH2500
FOR USE WITH GAS, OIL, and HYDRONIC FORCED AIR FURNACES
®
Copyright 2007 © , All Rights Reserved
281 Keyes Ave. Hampshire, IL 60140 • 847-683-7990 • Fax 847-683-7301 • www.bestairpro.com
®
TM
GH2500 mounts
to the supply
duct only.
Horizontal flow
GH2500
Blower
Motor
Side Cutaway View
Model GH2500 mounted
on the supply plenum
of an Upflow Furnace
Up Flow
GH2500
