Vertical Vent Tables And Figures - Lennox Hearth Products MPD35ST-NM-B Installation Instructions Manual

VERTICAL VENT FIGURES/TABLES
Note: Secure Vent (rigid vent pipe) is shown
in the figures; Secure Flex (flexible vent pipe)
may also be used.
Note: It is very important that the horizontal/in-
clined run be maintained in a straight (no dips)
and recommended to be in a slightly elevated
plane, in a direction away from the fireplace of
1/4" rise per foot (20 mm per meter) which is
ideal, though rise per foot run ratios that are
smaller are acceptable all the way down to at
or near level.
Note: SV4.5VF (Secure Vent), SF4.5VF (Secure
Flex) firestop/spacer must be used anytime vent
pipe passes through a combustible floor or ceil-
ing. SV4.5HF (Secure Vent), SF4.5HF (Secure
Flex)firestop/spacer must be used anytime vent
pipe passes through a combustible wall.
Note: 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.
Note: An elbow is acceptable as 1 foot of
vertical rise, except where an elbow is the
only vertical component in the system. (See
Figure 38 on page 22 ).
WARNING
Under no circumstances, may sepa-
rate sections of concentric flexible
vent pipe be joined together.
40 feet
(12.2 meters)
Maximum
u
When using Secure Flex, use
Firestop/Spacer SF4.5VF
Figure 29
- Top Vent - STRAIGHT
18
feet
u
Example: If 8 feet of (H) horizontal vent run is needed, then 4 feet minimum (V) vertical vent will be
required.
This table shows a 1(V) to 2(H) ratio. For every 1 foot of (V) vertical, you are allowed 2 feet of (H)
horizontal run, up to a maximum horizontal run of 8 feet.
Figure 30
u
Ceiling Firestop /
Spacer (SV4.5VF)
V1
Figure 31
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
Table A
V Minimum
H Maximum
(meter) feet (meter)
2 (0.610) 1 (0.305)
4 (1.219) 2 (0.610)
6 (1.829) 3 (0.914)
8 (2.438) 4 (1.219)
V + H = 40 feet (12.2 meters) Max.
H = 8 feet (2.4 meters) Max.
Ratio V to H ratio is 1:2
When using Secure Flex, use Firestop /
Spacer SF4.5VF.
- Side Vent - ONE 90 DEGREE ELBOW
H
u Ceiling Firestop /
Spacer (SV4.5VF)
v Wall Firestop/
Spacer (SV4.5HF)
u
When using Secure Flex, use
Firestop / Spacer SF4.5VF.
v
When using Secure Flex, use
Firestop / Spacer SF4.5HF.
- Top Vent - TWO 90 DEGREE ELBOWS
u
Ceiling Firestop / Spacer (SV4.5VF)
V
H
Table B
H Maximum V Minimum
feet (meter) feet
5 (1.524) Elbow Only
5 (1.524) 1
10 (3.048) 2
15 (4.572) 3
20 (6.096) 4
V + V + H = 40 feet (12.2 m) Max.
1
H = 20 feet (6.096 meters) Max.
Example: If 20 feet of (H) hori-
zontal vent run is needed, then 4
feet minimum of (V) vertical vent
will be required.
This table shows a 1(V) to 5(H)
V
ratio. For every 1 foot of (V) verti-
cal, you are allowed 5 feet of (H)
horizontal run, up to a maximum
horizontal run of 20 feet.
An elbow is acceptable as 1 foot
of vertical rise except where
an elbow is the only vertical
component in the system. See
Figure 38.
(meter)
(0.305)
(0.610)
(0.914)
(1.219)