6
Cassette Base Installation
It is important to locate the cassette unit in the center of
the area that is being conditioned. This will provide the
best air distribution.
1. If the unit is to be installed in an application that
includes a drop-down tile ceiling, remove the ceiling
tiles necessary to accommodate installation of the
four-way cassette. Before removing the drop ceiling
support grid, use a plumb line or laser device to
identify the center point of the structural ceiling.
Make
sure that the ceiling is supported before removing
any of the support grid. It may be necessary to add
extra support to maintain the structural integrity
of the drop ceiling.
2. If the unit is to be installed in an application that
includes a sheet rock (plasterboard) ceiling, the
installation site must be carefully measured and the
sheet rock must be cut to accommodate the cassette
unit. First, identify the center point of the installed
cassette. Use a plumb line to transfer the center mark
to the floor for future use. Use the provided template
to mark the area of the required opening. Carefully cut
the required opening.
Make sure that the removal
of the required ceiling support does not affect
the structural integrity of the ceiling. It may be
necessary to add extra support.
3. Use the unit as a template or use the provided paper
template to mark the location of the hanging brackets
on the floor. Use a plumb line or a laser to transfer the
bracket positions to the main structural ceiling.
4. Make sure that structure within ceiling void
such as a sub-floor or crawl space is able
to support the weight of the cassette unit.
It may be necessary to add extra support.
If the structural support is constructed of
concrete, install anchors to accept four ⅜”
threaded rods to suspend the cassette base.
If the structural support includes wooden joists,
use angle iron or a Unistrut channel fixed
securely in place to accept the ⅜” threaded rods.
NOTE -
Threaded rod (requirement of Lennox
warranty program) is the ONLY acceptable method of
suspending the unit; do not use chains or straps.
See
Figure 1.
5. Use either a mechanical lifting device or a minimum
of two people to raise the unit and insert the threaded
rods into the suspension brackets on the cassette
base. Slide a washer and then a nut onto each rod
below each suspension bracket. Use the leveling nut
(beneath suspension bracket) to adjust the cassette
base to the correct height. Remove the electrical
tape holding the upper washers and nuts in place
and tighten each of the four nuts above the brackets
down onto the brackets. This will ensure that the unit
remains level.
Figure 1. Suspending Methods
ANGLE IRON
BOLTED IN
PLACE ACROSS
WOODEN JOISTS
WOODEN JOIST
⅜” THREADE
D
ROD
ANGLE IRON
ACROSS
WOODEN JOISTS
ANCHOR
CONCRETE CEILING
USING ANCHORS
⅜” THREADE
D
ROD
L
⅜”
to
½
”
UNIT CHASSIS
DROP CEILING
LEVELING NUT
⅜” THREADE
D
ROD
SUSPENSION
BRACKET
STRUCTURAL
SUPPORT
Figure 2. Suspension Hardware
6. If the unit is being installed in an application that includes
a sheet rock (plasterboard) ceiling, it is required that
an access panel be installed in a suitable location.
This will also allow access for future maintenance
(requirement of Lennox warranty program).
7. Access is required during the commissioning process
to test the condensate disposal system (See Figure
9), to check the electronic expansion valve and
associated flare nuts (See Figure 3), and to check the
local disconnect. Ceiling framing should not restrict
access.
