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505059M 0511
This unit is approved for installation clearance to
combustible material as stated on the unit rating plate.
Accessibility and service clearances must take
precedence over combustible material clearances.
The air handler must be installed so that free access is
allowed to the coil/filter compartment and blower/control
compartment.
Horizontal applications of the air handler must be installed
sloped (approximately 5/8 inch) toward the drain pan
openings to ensure proper condensate drainage.
Installation Clearances
NON−DUCTED RETURN CLOSET INSTALLATION
The air handler can be installed in a closet with a false
bottom to form a return air plenum. It may also be installed
with a return air plenum under the air handler.
Louvers or return air grilles are field-supplied. Local codes
may limit application of systems without a ducted return to
single story buildings.
When a CB(X)26UH unit is installed in a closet with a
louvered return opening, the minimum open area for the
louvers will be:
S
320 square inches for −018 and −024 models;
S
360 square inches for −030 and −036 models;
S
450 square inches for −042 thru −060 models.
If the free area is not known, assume a 25% free area for
wood or a 75% free area for metal louvers or grilles. Using
the louver dimensions and the 25% or 75% assumption,
determine if the open area meets the minimum open area
listed above.
If a return air plenum is used, the return air grille should be
immediately in front of the opening in the plenum to allow
for the free flow of return air. When not installed in front of
the opening, there must be adequate clearance around the
air handler to allow for the free flow of return air.
Installation
GENERAL INFORMATION
WARNING
Improper installation, adjustment, alteration, service or
maintenance can cause property damage, personal inju-
ry or loss of life. Installation and service must be per-
formed by a qualified installer or service agency.
CB(X)26UH units are factory−assembled and configured
for installation in upflow or horizontal left−hand air
discharge applications.
Each unit consists of a blower assembly, refrigerant coil,
and controls, in an insulated galvanized steel factory
finished enclosure. Knockouts are provided for electrical
wiring entrance.
For ease in installation, it is best to make any necessary
coil configuration changes before setting air handler in
place.
If a filter is to be installed at the air handler, early models
require a filter rack be formed using factory−supplied
flanges. Lay the unit on its back and pry out the filter rack
tabs as shown in figure 1. Repeat procedure on opposite
side.
Figure 1. Filter Rack Tabs (Pre April 2006)
Later models are equipped with rails in which the filter
slides. Two screws and a bracket must be removed to
insert and remove the filter (see figure 2).
FILTER RAILS
SCREWS
BRACKET
(DUCT ADAPTER AND
SELF TAPPING SCREWS
− OPTIONAL FOR AT-
TACHING RETURN AIR
DUCT)
Figure 2. Filter Rails (April 2006 and Later)
UPFLOW APPLICATION
1. The air handler must be supported on the bottom only
and set on solid floor or field-supplied support frame.
Securely attach the air handler to the floor or support
frame.
2. If installing a unit in an upflow application, remove the
horizontal drain pan.
IMPORTANT − The horizontal
drain pan is not required in upflow air discharge
installations; its removal provides the best
efficiency and air flow.
3. Place the unit in the desired location and level it.
Connect return and supply air plenums as required
using sheet metal screws.
