Horizontal (Outside Wall) Termination System; Sv4.5L6/12/24/36/48; Vent Sections - Lennox Merit Plus Series Installation Instructions Manual

LENNOX HEARTH PRODUCTS • MERIT PLUS
HORIZONTAL (OUTSIDE WALL)
TERMINATION SYSTEM
Figure 39 (at right) and Figures 42 to 47 (Pag-
es 22 to 24) and illustrate the various horizontal
venting configurations that are possible for use
with these appliances. Secure Vent
plications are shown in these figures. Secure
Flex ® pipe may also be used. A Horizontal Vent
Table summarizes each system's minimum and
maximum vertical and horizontal length values
that can be used to design and install the vent
components in a variety of applications.
Both of these horizontal vent systems terminate
through an outside wall. Building Codes limit
or prohibit terminating in specific areas. Refer
to Figure 6 on Page 7 for location guidelines.
Secure Vent (SV4.5) direct vent system compo-
nents are unitized concentric pipe components
featuring positive twist lock connection (refer to
Figure 28 on Page 16). All appliances covered
in this document are fitted with collars having
locking inclined channels. The dimpled end of the
vent components fit over the appliance collar to
create the positive twist lock connection.
A. Plan the vent run.
Analyze the vent routing and determine the
types and quantities of sections required
4-1/2" (114 mm), 10-1/2" (267 mm), 22-1/2" (572
mm), 34-1/2" (876 mm) and 46-1/2" (1181 mm) net
section lengths are available. It is recommended
that you plan the venting so that a joint does not
occur in the ceiling or roof joists. Allow for elbows
as indicated in Figure 30 on Page 17.
Maintain a minimum 1" (25 mm) clearance to
combustibles on the vertical sections. Clearances
for the horizontal runs are; 3" (76 mm) on top, 1"
(25 mm) on sides, and 1" (25 mm) at the bottom.
B. Frame the exterior wall opening.
Locate the center of the vent outlet on the ex-
terior wall according to the dimensions shown
in Figure 12 on Page 10. Cut and/or frame an
opening, 10-1/2" x 12-1/8" (267 mm x 308mm)
inside dimensions, about this center.
C. Frame the ceiling opening.
If the vertical route is to penetrate a ceiling,
use plumb line to locate the center above
the appliance. Cut and/or frame an opening,
10-1/2" x 10-1/2" (267 mm x 267 mm) inside
dimensions, about this center (refer to Figure
27 on Page 16).
D. Attach vent components to appliance.
To attach a vent component to the appliance collar,
align the dimpled end over the collar, adjusting the
radial alignment until the four locking dimples are
aligned with the inlets of the four incline channels
on the collar (refer to Figure 28 on Page 16).
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.
20
DIRECT VENT GAS FIREPLACES (MPDP35/40) • INSTALLATION INSTRUCTIONS
®
Support
Building
Brackets
Support
Framing
SV4.5E90
® pipe ap-
Elbow
Ceiling
Vertical
Rise
Figure 39
The unitized design of the Secure Vent compo-
nents will engage and seal both the inner and
outer pipe elements with the same procedure.
Sealant and securing screws are not required.
E. 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 vent tables. To add another
vent component to a length of vent run, align the
dimpled end of the component over the inclined
channel end of the previously installed section,
adjusting the radial alignment until the four lock-
ing dimples are aligned with the inlets of the four
incline channels of the previous section. 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 28 on Page 16.
F. Install firestop/spacer at ceiling.
When using Secure Vent, use SV4.5VF firestop/
spacer at ceiling 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 appropri-
ate fasteners at each corner. The gap between
the vent pipe and a firestop can be sealed with
noncombustible caulking.
Remember to maintain 1" (25 mm) clearance
to combustibles, framing members, and attic
or ceiling insulation when running vertical
chimney sections.
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
TYPICAL HORIZONTAL VENT INSTALLATION
Horizontal / Inclined Run

SV4.5L6/12/24/36/48

Vent Sections

Firestop/Spacer
Support bracket spacing
every 5 ft (1.52 m)
See Figure 24 for vertical
vent section support.
Min. 1 ft vent Min. 1 ft. vent
section required.
section required
Fireplace
G. Support the vertical run sections.
On the vertical run, support the venting sys-
tem every 8 feet (2.4m) above the fireplace
vent outlet with field provided support straps
(Plumber's tape). Attach the straps to the vent
pipe and secure to the framing members with
nails or screws. See Figure 29 on Page 16.
H. Change vent direction.
At transition from or to a horizontal/inclined run,
install the SV4.5E45 and SV4.5E90 elbows in
the same manner as the straight vent sections.
The elbows feature a twist section to allow them
to be routed about the center axis of their initial
collar section to align with the required direc-
tion of the next vent run element. Twist elbow
sections in a clockwise direction only so as
to avoid the possibility of unlocking any of
the previously connected vent sections. See
Figure 30 on Page 17.
I. Continue installation of horizontal/inclined
sections. Continue with the installation of the
straight vent sections in horizontal/inclined run
as described in Step E. Install support straps
every 5 ft. (1.52 m) along horizontal/inclined
vent runs using conventional plumber's tape.
See Figure 39. It is very important that the
horizontal/inclined run be maintained in a
straight (no dips), slightly elevated plane.
The recommended incline is approximately
1/4" per foot (20 mm per meter) horizontal,
in a direction away from the fireplace. The
rise per foot run ratios that are smaller are
acceptable all the way down to at or near level.
Use a carpenter's level to measure from a
constant surface and adjust the support straps
as necessary.
It is important to maintain the required clear-
ances to combustibles: 1" (25 mm) at all sides
for all vertical runs; and 3" (76 mm) at the
top, 1" (25 mm) at sides, and 1" (25 mm) at
the bottom for all horizontal/inclined runs.
SV4.5HT-2
Termination
Exterior
Wall
SV4.5HT-2
Termination
Exterior
Wall