Installation Clearances; Installation - Lennox CBA25UH Installation Instructions Manual

NOTES –
During cooling operation, excessive sweating may occur
if the air handler is installed in a warm and humid space.
If installed in an unconditioned space, sealant should be
applied around the electrical wires, refrigerant tubing, and
condensate lines where they enter the cabinet.
Electrical wires should be sealed on the inside where they
exit the conduit opening. Sealant is required to prevent air
leakage into, and condensate from forming inside of, the
air handler, the control box, and on the electrical controls.
This unit is approved for installation clearance to combus-
tible material as stated on the unit rating plate. Accessi-
bility 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.

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 CBA25UH unit is installed in a closet with a lou-
vered return opening, the minimum open area for the lou-
vers will be:
• 320 square inches for -018 and -024 models;
• 360 square inches for -030 and -036 models;
• 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

Each unit consists of a blower assembly, refrigerant coil,
and controls in an insulated galvanized steel factory-fin-
ished enclosure. Knockouts are provided for electrical wir-
ing entrance.
For ease in installation, it is best to make any necessary
coil configuration changes before setting air handler in
place.
REFRIGERANT METERING DEVICE
CBA25UH units are equipped with a factory-installed
check/ expansion valve.
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 slope unit.
Connect return and supply air plenums as required
using sheet metal screws.
4 - Install units that have no return air plenum on a
stand that is at least 14" from the floor. This will
allow proper air return.
UP-FLOW /
DOWN-FLOW
DRAIN PAN
FIGURE 1. Upflow Configuration
HORIZONTAL APPLICATIONS
When removing the coil, there is a possibility of danger
of equipment damage and personal injury. Be careful
when removing the coil assembly from a unit installed in
right- or left-hand applications. The coil may tip into the
drain pan once it is clear of the cabinet. Support the coil
when removing it..
NOTE - When the unit is installed in horizontal applica-
tions, a secondary drain pan is recommended. Refer to
local codes.
NOTE - This unit may be installed in left-hand or right-
hand air discharge horizontal applications. Adequate sup-
port must be provided to ensure cabinet integrity. Ensure
that there is adequate room to remove service and access
panels if installing in the horizontal position.
Page 4
HORIZONTAL DRAIN PAN
(MUST BE REMOVED)
IMPORTANT