Venting Routes And Components; Horizontal Venting Table - Marquis Atrium MCVP42NH Installation Instructions Manual

Venting Routes and Components

Since it is very important that the vent system maintain its
balance between the combustion air intake and the flue gas
exhaust, certain limitations as to vent configurations apply and
must be strictly adhered to.
The table showing the relationship between vertical and
horizontal side wall venting will help to determine the various
vent lengths.
The maximum horizontal run is 20 ft/6.1 m when the vertical
run is 7 ft. / 2.1m (Figure #2). Note: 1/4" vertical rise is required
for every 12" of horizontal run.
The maximum number of 45 degree bends per side wall
installation is two (2) in the horizontal run and then you must
reduce the length of the horizontal by 18 inches for each 45
degree bend.
The maximum vertical run is 43 ft. / 13.1meters.
Special Note: For each 45 degree bend installed in the
horizontal run, the length of the horizontal run must be reduced
by 18" (45cm). This does not apply if the 45 degree bends are
installed on the vertical part of the vent system.
Example: If according to the table, the length of the horizontal
run is 10 feet, and two 45 degree bends are required, the
horizontal run length must be reduced to 7 feet.
2 additional 90° bends or equals are allowed. The horizontal
run must be reduced by 36" per each 90° bend, or 18" per
each 45° bend.
IMPORTANT: Always locate the fireplace in such a
way that a minimum of offsets and/or horizontal runs
are required. 1/4" vertical rise is required for every 12"
horizontal run.
12 FEET
Figure 1
20 FEET
MAX
Figure 2
Support Straps
Every 2 Feet
7 FEET
Venting Routes And Components
6 FEET
Plus ¼" Rise/Ft = 73-1/2"
For Propane Horizontal installations
the venting must be an additional
one foot above the minimum vertical
rise off the flue before going
How to Use the Horizontal Vent Table
1. Determine the height of the system and the number of
bends required.
2. Having determined the vertical distance determine the maxi-
mum horizontal section allowed.
3. Vent table has been established for 90˚ horizontal/vertical
runs. With use of flex pipe distance not having 90˚ bends will
not fall into vent table standards. See Fig. B.
-Horizontal Venting Table from Bottom of Fireplace-
For venting to a maximum of 43ft (13.1 meters).
Total Vertical
Feet Meters
55" (MCVP42N)
67" (MCVP42LP)
6
7
8
9
10
11
12
13
14
15
20
25
30
43 (Max)
Example A:
If the vertical dimension from
the floor of the fire- place is
6ft, the horizontal run to the
wall flange of the vent
termination must not exceed
12ft.
NOTE: The final location
of the fireplace must be
such that the horizontal
vent dimensions fall with-
in those stated on the
graph. The Maximum
Vertical vent run is 43ft.
(13.1 meters).
Important: Minimum
clearance between vent
pipes and combustible
materials is1 inch (25mm).
horizontal.
Max Total Horizontal
Feet
1.3 5
1.6 8
1.8 12
2.1 20
2.4 20
1.8 20
3.0 20
3.4 20
3.7 20
4.0 20
4.3 20
4.6 20
6.1 20
7.6 15
9.1 10
13.1 0
12 FEET MAX
Meters
1.5
2.4
3.7
6.1
6.1
6.1
6.1
6.1
6.1
6.1
6.1
6.1
6.1
4.6
3.0
0
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