24 NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
HORIZONTAL VENT FIGURES/TABLES (continued)
H1
V
H
V
H
H1
u When using Secure Flex, use Firestop
/ Spacer SF4.5VF
v
When using Secure Flex, use Firestop
/ Spacer SF4.5HF
u When using Secure Flex, use Firestop /
Spacer SF4.5VF
v
When using Secure Flex, use Firestop /
Spacer SF4.5HF
u Ceiling Firestop
/ Spacer (SV4.5VF)
vWall Firestop/
Spacer (SV4.5HF)
u Ceiling Firestop
/ Spacer (SV4.5VF)
vWall Firestop/
Spacer (SV4.5HF)
vWall Firestop/
Spacer (SV4.5HF)
Table G
H
+H1
Maximum H
Maximum
V Minimum
feet (meter) feet (meter) feet (meter)
5(1.524) 2(0.610) 1(0.305)
10 (3.048) 4(1.219) 2(0.610)
15 (4.572) 6(1.829) 3(0.914)
20 (6.096) 8(2.438) 4(1.219)
V + H + H1 = 40 feet (12.2 m) Max
H = 8 feet (2.438 meters) Max.
H + H1 = 20 feet (6.096 meters) Max.
Example: If 20 feet of (H + H1) horizontal 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+
H1) horizontal run, up to a maximum horizontal
run of 20 feet.
Table H
H + H1 Maximum V Minimum
feet (meter) feet (meter)
3(0.914) 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 + H + H1 = 40 feet (12.2 m) Max.
H + H1 = 20 ft. (6.096 m) Max.
Figure 45 - Side Vent, TWO 90 DEGREE ELBOWS
Figure 46 - Top Vent, TWO 90 DEGREE ELBOWS
Square termination
(SV4.5HT-2) shown
Square termination
(SV4.5HT-2) shown
See Table 8 on Page 23 as an aid in venting
component selection for a particular range of
exterior wall thicknesses.
See Table 8 on Page 23 as an aid in venting
component selection for a particular range
of exterior wall thicknesses.
Example: If 20 feet of (H + H1) horizontal 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+
H1) 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 44.