Horizontal Vent Tables And Figures; When Using Secure Flex, Use Firestop/Spacer Sf4.5Vf; Table 8 - Lennox Merit Plus Series Installation Instructions Manual

LENNOX HEARTH PRODUCTS • MERIT PLUS
HORIZONTAL VENT FIGURES/TABLES
Note:
• Secure Vent ® components (rigid vent pipe and terminal) are shown in
the figures; Secure Flex
may also be used.
• Two 45-degree elbows may be used in place of one 90 degree elbow.
The same rise to run ratios, as shown in the venting figures for 90
elbows, must be followed if 45-degree elbows are used.
• 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.
• SV4.5VF (Secure Vent), SF4.5VF (Secure Flex) firestop/spacer must be
used anytime vent pipe passes through a combustible floor or ceiling.
SV4.5HF (Secure Vent), SF4.5HF (Secure Flex) firestop/spacer must be
used anytime vent pipe passes through a combustible wall.
Under no circumstances, may separate sections of
concentric flexible vent pipe be joined together.
Venting Components Required for Various Exterior Wall Thick-
nesses, when using Typical Termination Kits
Vent Components Required
Termination Kit Only
Termination Kit and 6 In. Vent
Section (SV4.5L6)
Termination Kit and 12 in.
Vent Section (SV4.5L12)
Termination Kit and Tele-
scopic Section (SV4.5L12)

Table 8

Remove inside rear vent restrictor if vented over 7" horizontally
(see Page 13).
H = 28 in. (711 mm) Maximum.
7 in
(178 mm)
Only the square termination (SV4.5HT-2) may be used.
See Table 8 as an aid in venting component selection
for a particular range of exterior wall thicknesses.
Figure 42: Rear Vent - NO ELBOWS
22
® components (flexible vent pipe and terminal)
WARNING
Exterior Wall Thickness - inches (mm)
6 to 9-1/4 (152 to 235)
10-3/4 to 14 (273 to 356)
16-3/4 to 20 (426 to 508)
11-3/4 to 20 (299 to 508)
Note: See Figure 41 showing wall thickness range
when using SV4.5HT-2 termination kit.
H
Wall Firestop/
Spacer
SV4.5HF**
**When using Secure Flex, use
Wall Firestop/Spacer SF4.5HF.
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
DIRECT VENT GAS FIREPLACES (MPDP35/40) • INSTALLATION INSTRUCTIONS
®
H Maximum
feet
3
7
11
14
18
20
V + H = 40 feet (12.2 m) Max.
H = 20 ft. (6.096 m) Max.
When using Secure Flex,
use Firestop/Spacer
SF4.5VF.
When using Secure Flex,
use Firestop/Spacer
SF4.5HF.
Typical termination shown.
See Table 8 as an aid in venting component selection
for a particular range of exterior wall thicknesses.
Figure 43: Top Vent - ONE 90-DEGREE ELBOW
Example: If 20 feet of (H)
TABLE E
horizontal vent run is needed,
V Minimum
then 4 feet minimum of (V)
vertical vent will be required.
(meters) feet (meters)
Note:
(0.914) * (0.061)
• An elbow may NOT be at-
(2.134) 3 (0.914)
(3.35) 4 (1.22)
• Install the U-shaped vent
(4.267) 5 (1.524)
(5.49) 6 (1.729)
(6.2) 7 (2.134)
* Minimum 1 ft. section and
H
Wall Firestop/Spacer
(SV4.5HF)
Firestop/Spacer
tached directly to the vent
collar.
restrictor in any vent run with
more than 8 ft. of vertical
rise. See Pages 13 and 14.
elbow
V
Min. One
Foot Vent
Section
Required
Ceiling
(SV4.5VF)