Lennox MPD35CNE, Installation Instructions Manual

Page: 17 / 38

17
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
LENNOX HEARTH PRODUCTS • MERIT PLUS
®
DIRECT VENT GAS FIREPLACES (MPD33/35/40/45) • INSTALLATION INSTRUCTIONS
TABLE C
H +H
1
Maximum H Maximum V Minimum
feet feet feet
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.
(meters) (meters) (meters)
Example: If 20 feet of (H) 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) horizontal run, up
to a maximum horizontal run of 20 feet.
NOTE: Install the U-shaped vent restrictor in any vent run
with more than 8 ft of vertical rise (See Page 13 ).
TABLE D
H + H
1
Maximum
V Minimum
feet 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)
H + H
1
= 20 feet (6.096 m) Max.
V + V
1
+ H + H
1
= 40 ft. (12.192 m) Max.
(meters) (meters)
Example: If 20 feet of (H) 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) 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 36 .
NOTE: Install the U-shaped vent restrictor in any vent run with more
than 8 ft of vertical rise (See Page 13 ).
VERTICAL VENT FIGURES/TABLES
(continued)
Figure 30 - Rear Vent - THREE ELBOWS
Figure 31: Top Vent - THREE ELBOWS
H1
V
V1
H
Ceiling
Firestop/Spacer
SV4.5VF*
Wall
Firestop/Spacer
SV4.5HF**
* When using Secure Flex , use
Ceiling Firestop/Spacer SF4.5VF .
** When using Secure Flex , use
Wall Firestop/Spacer SF4.5HF .
Ceiling
Firestop/Spacer
SV4.5VF*
V
H1
H
V1
Ceiling
Firestop/Spacer
SV4.5VF*
Wall
Firestop/Spacer
SV4.5HF**
* When using Secure Flex , use
Ceiling Firestop/Spacer SF4.5VF .
** When using Secure Flex , use
Wall Firestop/Spacer SF4.5HF .