Lennox Hearth Products LSS-35CN Installation Instructions Manual page 13

Where required, a telescopic vent section
(SV4.5LA) may be used to provide the in-
staller with an option in installing in tight and
confined spaces or where the vent run made
up of fixed length pieces develops a joint in a
undesirable location, or will not build up to the
required length. The SV4.5LA Telescopic Vent
Section has an effective length of from 1-1/2"
(38 mm) to 7-1/2" (191 mm). The SV4.5LA is
fitted with a locking inclined channel end (iden-
tical to a normal vent section component) and
a plain end with 3 pilot holes. Slip the plain end
over the locking channel end of a standard
SV4.5 vent component the required distance
and secure with three screws.
Maintain a minimum 1" (25 mm) clearance to
combustible materials for all vertical elements.
Clearances for all horizontal elements are 3"
(76 mm) on top, 1" (25 mm) on sides and 1"
(25 mm) on the bottom.
A. Frame ceiling opening - Use a plumb line
from the ceiling above the appliance to locate
center of the vertical run. Cut and/or frame an
opening, 10-1/2" x 10-1/2" (267mm x 267mm)
inside dimensions, about this center mark
( Figure 16 ).
10¹⁄₂" Min.
(267 mm)
Figure 16
B. Attach vent components to appliance -
Secure Vent SV4.5 direct vent system compo-
nents are unitized concentric pipe components
featuring positive twist lock connections ( see
Figure 17 ).
All of the appliances covered in this document are
fitted with collars having locking inclined chan-
nels. The dimpled end of the vent components fit
over the appliance collar to create the positive
twist lock connection.
Figure 17
Arrow
Arrow
Figure 18
To attach a vent component to the appliance
collar, align the dimpled end over the collar,
10¹⁄₂" Min.
adjusting the radial alignment until the four
(267 mm)
locking dimples are aligned with the inlet of the
four inclined channels on the collar ( refer to
Figure 17 ). Push the vent component against
the collar until it fully engages, then twist the
component clockwise, running the dimples
down and along the incline channels until they
seat at the end of the channels.
The unitized design of the Secure Vent com-
ponents will engage and seal both the inner
and outer pipe without the need for sealant or
screws. If desired, a #6 x 1/2" screw may be
used at the joint, but is not required as the pipe
will securely lock when twisted.
C. Attach vent components to each other -
Other vent sections may be added to the previ-
ously installed section in accordance with the
requirements of the vertical vent figures and
tables. To add another vent component to a
length of vent run, align the dimpled end over the
inclined channel end of the previously installed
section, adjusting the radial alignment until the
four locking dimples are aligned with the inlets of
the four incline channels of the previous section.
NOTE: DIAGRAMS & ILLUSTRATIONS NOT TO SCALE.
First Vent
Component
Align the dimple (four places)
with the opening of the locking
incline channel on appliance
collar. Twist vent component
clockwise to engage and seal.
Dimple
Locking
Incline Channel
Appliance collar
Vent / Appliance Collar
Connection
Align the dimple (four places) of the
upper vent section with the opening of
the locking incline channel on the
lower vent section. Twist vent
component clockwise to engage and
seal until arrow and dimple align.
Dimple
Locking
Incline Channel
Connected
Vent Sections
Arrow
Vent / Vent Section
Connection
Push the vent component against the previous
section until it fully engages, then twist the
component clockwise running the dimples down
and along the incline channels until they seat at
the end of the channels. This seating position
is indicated by the alignment of the arrow and
dimple as shown in Figure 18.
D. Install firestop/spacer at ceiling - When using
Secure Vent, use SV4.5VF firestop/spacer at ceil-
ing joists; when using Secure Flex, use SF4.5VF
firestop/spacer. If there is living space above the
ceiling level, the firestop/spacer must be installed
on the bottom side of the ceiling. If attic space is
above the ceiling, the firestop/spacer must be
installed on the top side of the joist. Route the vent
sections through the framed opening and secure
the firestop/spacer with 8d nails or other appro-
priate fasteners at each corner.
Remember to maintain 1" (25 mm) clearance
to combustibles, framing members, and attic
or ceiling insulation when running vertical
chimney sections.
E. Support the vertical vent run sections -
Support the vertical portion of the venting sys-
tem every 8 feet (2.4m) above the fireplace vent
outlet using field provided support straps (con-
ventional plumber's tape). Secure the plumber's
tape to the framing members with nails or screws.
Loop the tape around the vent, securing the
ends of the tape to the framing. If desired,
sheet metal screws #6 x 1/2" length may be
used to secure the support straps to the vent
pipe . See Figure 19.
Blocking
Support Straps
(Plumber's tape)
8 feet (2.4 m)
Maximum
Figure 19
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