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IMPORTANT VENTING CONFIGURATION NOTES
See Figure 14 [MASTER FLUE VENTING REQUIREMENTS CHART].
HIGH ALTITUDE INSTALLATION INFORMATION
: Prior to installing at altitudes higher than 7500, please contact the
Mendota technical service department for specific venting requirements and venting restrictions.
MAXIMUM HORIZONTAL RUN
A. Maximum Horizontal Run allowed is 20 feet if a vertical starter section that is between 4 feet to 30 feet is con-
nected directly to this fireplace’s flue starter collar and no more than three (3) 90 degree elbows are used.
B. Maximum Horizontal Run allowed is
18” if a 90-degree elbow is connected directly to this fireplace’s flue starter
collar.
MAXIMUM VENT SYSTEM LENGTH
A. Combined total length of all straight pipe sections in the vent system shall be less than 50 feet.
B. Combined total length of all straight pipe sections in the vent system shall be less than 50 feet when using three
(3) 90-degree elbows or equivalent and terminating the vent system horizontally.
C. Combined total length of all straight pipe sections in the vent system shall be less than 50 feet when using four (4)
90-degree elbows or equivalent and terminating vertically.
HOW TO CALCULATE THE VENT SYSTEM LENGTHS
For calculation purposes and usage of charts in this manual, simply add the lengths of all individual straight pipe sections.
For example: if you use two 2-foot lengths and one 4-foot length, the total vent system length will be 2+2+4 = 8 feet.
USING 90
0
ELBOWS
IN ZONE “B”
The FV41-M Fireplace by MENDOTA allows maximum flexibility in the use of 90
o
elbows in the vent system. The length
o
f the first straight vertical section directly connected to the fireplace’s starter collar determines the maximum horizontal
run and the number of 90
0
elbows allowed for this fireplace.
For vent systems that provide a starting vertical section that is 4 feet or longer, you may connect up to 20 feet of horizon-
tal pipe and up to three (3) 90
0
elbows within the 20 feet run in any configuration and terminate the vent horizontally. No
reduction in horizontal run is required for the elbows used as long as the 4 feet long vertical starter section is connected
directly to this fireplace’s starter collar.
USING 90
0
ELBBOWS IN ZONE “A”.
For vent systems that provide a starting vertical section less than 4 feet, the following rules apply:
a. You must use the Master Flue Venting Requirements Chart.
See Zone “A” below the 4’ vertical run line.
b. A single 90
º
vertical-to-horizontal elbow is already calculated into the allowable maximum 20' horizontal run. The Vent-
ing Requirements Chart (
Figure 14
) assumes that for all horizontal runs calculated, one 90
0
elbow is used within the vent-
ing system.
Each additional 90
º
elbow reduces the maximum horizontal distance by 3'.
c. If you plan to use more than one 90
0
elbow within the vent system, first use the Venting Requirements Chart (Figure 14)
and calculate the maximum horizontal run you are allowed based on the first vertical section connected directly to the fire-
place. From this maximum horizontal run calculated, subtract 3 feet for each additional 90
0
elbow you will use.
Example 1:
Assume you are using a 3 feet long starter vertical section. This should allow, per figure 15, 15-1/2 feet of
horizontal run. If you want to use three 90
0
elbows, subtract 6 feet for two elbows from the 15-1/2 feet max-
imum allowed [3 feet for each elbow after the first elbow]. This yields 9-1/2 feet as the maximum horizontal
run that you are allowed to install using the 3 foot vertical starter section.
CAUTION:
If a vertical-to-horizontal discharge elbow or a horizontal-to-horizontal discharge elbow is enclosed within a
wall, floor or ceiling, a top air space clearance of 3" must be maintained.
USING 45-DEGREE ELBOWS
Two 45-degree elbows may be used in place of one 90-degree elbow. On 45-degree runs, one foot of diagonal pipe is
equal to 8-1/2 inches horizontal run and 8-1/2 inches vertical run. Two 45-degree elbows may be connected directly to
the vent starter adapter on this fireplace to create an offset to provide the required clearances to combustible framing or
sheathing materials.
Two 45-degree elbows may be connected directly to the top of this fireplace to create a horizontal offset. 20 feet maxi-
mum horizontal run allowed with this offset configuration only if the first vertical section connected directly to the last 45-
degree elbow is more than 4 feet long. For maximum allowable horizontal distances with the 45-degree offsets, see the
Master Venting Configuration Chart.
Note:
Each horizontally positioned 45
º
elbow reduces the maximum horizontal distance by 1½ '.
SUPPORT:
Horizontal runs of pipe will require one vent support for every 3 ft. of pipe.
