16
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
40 feet (12.2 meters)
Maximum
*Ceiling
Firestop/Spacer
(SV4.5VF)
*When using
Secure Flex, use
Firestop/Spacer
SF4.5VF
H
V
V1
*Ceiling
Firestop/Spacer
(SV4.5VF)
**Wall
Firestop/Spacer
(SV4.5HF)
**When using Secure
Flex, use Firestop/Spacer
SF4.5HF
*When using Secure Flex,
use Firestop/Spacer
SF4.5VF
Figure 30 - Rear Vent -
ONE 90 DEGREE ELBOW
Figure 29 - Top Vent - STRAIGHT
Figure 31 - Top Vent - TWO 90 DEGREE ELBOWS
VERTICAL VENT FIGURES/TABLES
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 20 ).
Note: Secure Vent (rigid vent pipe) is shown
in the figures; Secure Flex (flexible vent pipe)
may also be used.
A Vent Restrictor, as shown in Figure 18 on Page
12, must be used in this application.
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.
TABLE A
H Maximum V Minimum
feet feet
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
(meters)
(meters)
Example: If 20 feet of (H) horizon-
tal vent run is needed, then 4 feet
minimum of (V) vertical vent will
be required.
This table shows a 1 (V) to 5 (H) ratio.
For every 1 foot of (V) vertical, 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.
TABLE B
H Maximum
V Minimum
feet
(meters)
feet
5
(1.524)
Elbow Only
5
(1.524)
1
(0.305)
10
(3.048)
2
(0.610)
15
(4.572)
3
(0.914)
20
(6.096)
4
(1.219)
V + V
1
+ H = 40 feet (12.2 m) Max.
H = 20 feet (6.096 meters) Max.
(meters)
WARNING
Under no circumstances, may separate sections of concentric flexible vent
pipe be joined together.
V
H
*Ceiling
Firestop/Spacer
(SV4.5VF)
*When using Secure Flex,
use Firestop/Spacer
SF4.5VF
**When using Secure
Flex, use Firestop/Spacer
SF4.5HF