Installation Of Wall Sleeve; Installation Of Indoor Unit On Wall Mounting Plate; Indoor Unit Condensate Piping Connections - Lennox MHA Series Installation Instructions Manual

wall construction. Use the appropriate type of
anchors for the application.
3. The wall mounting plate must be installed flush
against the wall so that the indoor unit will be flush
after installation. Any space between the wall and unit
will cause noise and vibration.
4. The wall mounting plate must be installed horizontally
level on the wall.

Installation of Wall Sleeve

The utility bundle may be routed out of the back of the unit
or out either side. If the bundle is to be routed out the back
through an external wall, use a field-provided wall sleeve
to protect the utility bundle.
NOTE: If the utility bundle will be routed out the side of the
indoor unit and up the wall above a false ceiling,
continue to the next section.
1. Prior to making the hole and installing the wall sleeve
for the utility bundle, check to ensure that there are
no other utilities located in the wall behind the hole
location.
2. Cut a hole in the wall using a suitable hole saw. Hole
should be at a slight downward slant ­ 3/16" to 3/8"
toward the outdoor side.
3. Measure the thickness of the wall from the inside
edge to the outside edge and cut the field-provided
wall sleeve at a slight angle 1/4" (6 mm) shorter than
the thickness of the wall.
INSIDE
Figure 14. Boring Hole for Wall Sleeve
USE SUITABLE TOOL TO CUT PVC FOR WALL
SLEEVE AT SLIGHT ANGLE AS SHOWN.
Figure 15. PVC Wall Sleeve Installation
NOTE: When passing bundled services through an
exterior brick or concrete wall, protect the
copper pipes and wiring from the effects of these
construction materials by using a sleeve made
of suitable material. The integrity of copper pipe
and wiring can deteriorate when exposed to these
construction materials.
OUTSIDE
Typical
installation
procedure
shown.

Installation of Indoor Unit on Wall Mounting Plate

1. A length of field-provided flexible condensate piping
should be connected to the drain prior to securing the
unit to the wall mounting plate.
2. If the factory­provided refrigerant piping connections
and field-provided flexible condensate piping are long
enough to enable final field connections after unit is
installed on wall mounting plate, use field-provided
tape to bundle them together.
3. The utility bundle may be routed out of the back of
the unit or out either side. If the bundle is to be routed
out the back through an external wall, feed the utility
bundle through the wall sleeve. If the utility bundle is
to be routed out of the side of the indoor unit and up
an inside wall, carefully form the utility bundle so that
it makes a gentle 90° turn.
4. Align the back of the indoor unit with the hooks at the
top of the wall mounting plate. Move the unit from side
to side to make sure that it settles securely.
5. The bottom of the unit can be lifted to facilitate
refrigerant piping and condensate drain connections,
if necessary.
HOOKS AT TOP
OF MOUNTING
BRACKET
Figure 16. Secure Unit to Wall Mounting Plate

Indoor Unit Condensate Piping Connections

IMPORTANT
Make sure that drain piping is properly routed and
insulated to prevent both leaks and condensation.
1. Use a field-provided hose clamp to secure the drain
line stub on the side of the cabinet to a field-supplied
1­inch (25 mm) drain line.
NOTE: Take care not to over-tighten the hose clamps this
may damage the drain line stub.
NOTE: Connection between stub and drain line must be
watertight. Apply non-hardening plumbing joint
compound if needed to ensure a watertight seal.
2. Confirm proper slope (not less than 1/4 inch per foot
(18 mm per meter) and routing of condensate lines to
ensure moisture is drained away from the indoor unit.
3. Drain should be as short as possible and should
not have any droops or kinks that would restrict
condensate flow and shall be approved resistant pipe.
There must be a 2­inch (51 mm) space between the
end of the condensate drain and the final termination
point (ground, open drain, etc.) to ensure that the line
will drain freely.
4. After the system installation is complete, the
condensate drain line must be checked for leaks
and proper drainage. If a field-provided condensate
8
TEMPORARY
SPACER
(To facilitate
connections)