NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
18
Table D
H + H1 Maximum V Minimum
feet (meter) feet (meter)
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)
H + H1 = 20 feet (6.096 m) Max.
V + V1 + H + H1 = 40 ft. (12.192 m) Max.
Example: If 20 feet total (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 total
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 36.
Table C
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 + V1 + 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 total (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 total horizontal run of 20 feet.
When using Secure Flex, use Firestop / Spacer SF4.5VF
When using Secure Flex, use Firestop / Spacer SF4.5HF
H1
V
V1
H
V
H1
H
V1
Figure 30 - Side Vent - THREE ELBOWSFigure 31 - Top Vent - THREE ELBOWS
Ceiling
Firestop / Spacer
(SV4.5VF)

Wall Firestop/
Spacer (SV4.5HF)
Ceiling Firestop /
Spacer (SV4.5VF)
When using Secure Flex, use Firestop / Spacer SF4.5VF
When using Secure Flex, use Firestop / Spacer SF4.5HF
Ceiling
Firestop / Spacer
(SV4.5VF)
Wall Firestop/
Spacer (SV4.5HF)
VERTICAL VENT FIGURES / TABLES (CONTINUED)