Vii-Accessories - Lennox LGM Series Manual

VII-ACCESSORIES

The accessories section describes the application of most
of the optional accessories which can be factory or field
installed to the LGM units.
A-Roof Curbs
When installing the LGM units on a combustible surface
for downflow discharge applications, the hybrid C1CUR-
B70C-1 8-in height, C1CURB71C-1 14-in height, C1CUR-
B72C-01 18-in height and C1CURB73C-1 24-in roof
mounting frame is used. The assembled hybribd mount-
ing frame is shown in figure 28. Refer to the roof mount-
ing frame installation instructions for details of proper as-
sembly and mounting. The roof mounting frame MUST be
squared to the roof and level before mounting. Plenum sys-
tem MUST be installed before the unit is set on the mount-
ing frame. Typical roof curbing and flashing is shown in
figure 29. Refer to the roof mounting frame installation in-
structions for proper plenum construction and attachment.
For horizontal discharge applications, use the standard
C1URB14C-1 26-in or C1CURB16C-1 37-in height roof
mounting frame. This frame converts unit from down-flow
to horizontal air flow. The 37 inch horizontal frame meets
National Roofing Code requirements. The roof mounting
frames are recommended in all other applications but
not required. If the LGM units are not mounted on a flat
(roof) surface, they MUST be supported under all edges
and under the middle of the unit to prevent sagging. The
units MUST be mounted level within 1/16" per linear foot
or 5mm per meter in any direction.
ASSEMBLED HYBRIDROOF CURB
FIGURE 28
UNIT BASE
BOTTOM
FIBERGLASS
INSULATION
(Furnished)
NAILER STRIP
(Furnished)
RIGID INSULATION
(Field Supplied)
ROOF
MOUNTING FRAME
(Extends around entire
perimeter of unit)
B-Transitions
Optional supply/return transitions C1DIFF33C-1 and
C1DIFF34C-1 are available for use with LGM series units
utilizing optional C1CURB roof curbs. Transition must be
installed in the roof curb before mounting the unit to the
frame. Refer to the manufacturer's instructions included
with the transition for detailed installation procedures.
C-C1DAMP10 & E1DAMP20 Outdoor Air Dampers
C1DAMP10C and E1DAMP20C (figure 30) consist of a
set of dampers which may be manually or motor operated
to allow up to 25 percent outside air into the system at all
times (see figure 30). Either air damper can be installed
in LGM units. Washable filter supplied with the outdoor air
dampers can be cleaned with water and a mild detergent.
It should be sprayed with Filter Handicoater when dry prior
to reinstallation. Filter Handicoater is R.P. Products coat-
ing no. 418 and is available as Part No. P-8-5069.
Page 40
TYPICAL FLASHING DETAIL
UNIT BASE
RAIL
COUNTER FLASHING
(Field Supplied)
CANT STRIP
(Field Supplied)
ROOFING
MATERIAL
FIGURE 29