Lennox Hearth Products Electronic LMDV-3530-CNM Installation Instructions Manual page 20

HORIZONTAL VENT FIGURES / TABLES (CONTINUED)
Square termination (SV4.5HT-2) shown.
Figure 39
- Rear Vent - TWO 90 DEGREE ELBOWS
H 1
Square termination (SV4.5HT-2) shown.
See Table 12 on Page 19 as an aid in venting
component selection for a particular range of
exterior wall thicknesses.
Figure 40
- Top Vent - TWO 90 DEGREE ELBOWS
20
H
H 1
�
Firestop/Spacer
(SV4.5HF)
�
Firestop/Spacer
(SV4.5VF)
V
�
Wall Firestop/Spacer
(SV4.5HF)
H
� Wall Firestop/Spacer
(SV4.5HF)
�
Ceiling
Firestop/Spacer
(SV4.5VF)
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
H
+H
1
feet
5
10
Wall
15
20
Ceiling
V
Example: If 20 feet of (H + H
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+ H
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 37.
Table H
Maximum H Maximum
(meter) feet (meter)
(1.524) 2 (0.610)
(3.048) 4 (1.219)
(4.572) 6 (1.829)
(6.096) 8 (2.438)
V + H + H 1 = 40 feet (12.2 m) Max
H = 8 feet (2.438 meters) Max.
H + H 1 = 20 feet (6.096 meters) Max.
Example: If 20 feet of (H + H ) horizontal vent run is needed,
1
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+ H
to a maximum horizontal run of 20 feet.
See Table 12 on Page 19 as an aid in venting component
selection for a particular range of exterior wall thick-
nesses.
Table J
H Maximum
+ H
1
feet (meter)
3 (0.914)
5 (1.524)
10 (3.048)
15 (4.572)
20 (6.096)
H
V + + H = 40 feet (12.2 m) Max.
1
H + H = 20 ft. (6.096 m) Max.
1
) horizontal vent run is needed,
1
V Minimum
feet (meter)
1 (0.305)
2 (0.610)
3 (0.914)
4 (1.219)
) horizontal run, up
1
V Minimum
feet (meter)
Elbow Only
1 (0.305)
2 (0.610)
3 (0.914)
4 (1.219)
) horizontal run, up
1