Vii-Accessories - Lennox LDT Series Information

VII-ACCESSORIES

The accessories section describes the application of most
of the optional accessories which can be factory or field
installed to the LDT units.
A-Roof Curbs
When installing the LDT units on a combustible surface for
downflow discharge
C1CURB70C-1 8-in height, C1CURB71C-1 14-in height,
C1CURB72C-01 18-in height and C1CURB73C-1 24-in
roof mounting frame is used. The assembled hybrid
mounting frame is shown in figure 30. Refer to the roof
mounting frame installation instructions for details of proper
assembly and mounting. The roof mounting frame MUST
be squared to the roof and level before mounting. Plenum
system MUST be installed before the unit is set on the
mounting frame. Typical roof curbing and flashing is shown
in figure 31. Refer to the roof mounting frame installation
instructions for proper
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 LDT 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 30
applications, the hybrid
plenum construction
TYPICAL FLASHING DETAIL
UNIT BASE
BOTTOM
FIBERGLASS
INSULATION
(Furnished)
NAILER STRIP
(Furnished)
RIGID INSULATION
(Field Supplied)
ROOF
and
MOUNTING FRAME
(Extends around entire
perimeter of unit)
B-Transitions
Optional supply/return transitions C1DIFF33C-1 and
C1DIFF34C-1 are available for use with LDT 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 32) 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 32). Either air damper can be installed in LDT
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
re-installation. Filter Handicoater is R.P. Products coating
no. 418 and is available as Part No. P-8-5069.
Page 37
UNIT BASE
RAIL
COUNTER FLASHING
(Field Supplied)
CANT STRIP
(Field Supplied)
ROOFING
MATERIAL
FIGURE 31