12
20306748
MLDV Series Gas Fireplace
VENTING INSTALLATION
INSTALLATION PLANNING
There are two basic types of direct-vent installation:
•
Horizontal Termination
•
Vertical Termination
It is important to select the proper length of vent pipe for
the type of termination you choose. It is also important to
note the wall thickness.
FOR HORIZONTAL TERMINATION
Select the amount of vertical rise desired. All horizontal run
of venting must have 1/4" rise for every 12" of run towards
the termination below 7
1
/
2
feet of vertical rise. With 7
1
/
2
feet
or more vertical rise off top of
fi
replace, the horizontal run
may run level. NEVER run vent piping downward.
You may use up to three 90° elbows in this vent con
fi
gu-
ration. Refer to Horizontal Termination Con
fi
gurations on
Pages 17 and 18.
FOR VERTICAL TERMINATION
Measure the distance from the
fi
replace
fl
oor to the ceil-
ing. Add the ceiling thickness, the vertical rise in an attic
or second story, and allow for suf
fi
cient vent height above
the roof line.
NOTE:
You may use two 45° elbows in place of a 90° elbow.
You must follow rise to run ratios when using 45° elbows.
The appliance is approved for use with three 90° elbows
maximum or a combination of 90° and 45° elbows up to a
maximum of 270°.
For two-story applications,
fi
restops are required at each
fl
oor level. If an offset is needed in the attic, additional pipe
and elbows will be required.
NOTICE
When installing in a chase, you should insulate
the chase as you would the outside walls of
your home. This is especially important in cold
climates. Insulation should be considered a
combustible material. Maintain proper clearances
to all combustible materials.
WARNING
Always maintain minimum clearances around vent
systems. The minimum clearance to combustibles
for horizontal vent pipe are 3" at the top and 1" at the
sides and bottom of the vent system until the pipe
penetrates the nearest vertical wall (1" required). A
1" minimum clearance all around the pipe must be
maintained at outside wall and on vertical runs. Do
not pack the open air spaces with insulation or other
materials. This could cause high temperatures and
may present a
fi
re hazard.
*Unless the vertical run is 7
1
⁄
2
feet or higher (top vent
units only), the clearances for the horizontal run is
1" at the top.
Never run the vent pipe down. This may cause
excessive temperatures which could cause a
fi
re.
WARNING
Treatment of
fi
restops and construction of the chase
may vary from building type to building type. These
instructions are not substitutes for the requirements
of local building codes. You must follow all local
building codes.
WARNING
WARNING
Read all instructions completely and thoroughly
before attempting installation. Failure to do so
could result in serious injury, property damage or
loss of life. Operation of improperly installed and
maintained venting system could result in serious
injury, property damage or loss of life.
You may use a chase with a vent termination with exposed
pipe on the exterior of the house. Refer to
Installing Vent
System in a Chase
below. If pipe is enclosed in chase, it
is not exposed.
It is very important that the venting system maintain its
balance between the combustion air intake and the
fl
ue
gas exhaust. Certain limitations apply to vent con
fi
gurations
and must be strictly followed.
INSTALLING A VENT SYSTEM IN AN
OUTSIDE CHASE
A chase is a vertical boxlike structure built to enclose
venting that runs along the outside of a building. A chase
is required for such venting.
Horizontal sections of this vent system require a
minimum of 3" clearances to combustibles at the top
of the
fl
ue and 1" clearance at the sides and bottom
until the
fl
ue penetrates the outside wall. A minimum
1" clearance all around the
fl
ue is acceptable at
this point of penetration. If vertical rise is 7
1
⁄
2
"
feet or higher when top venting, the clearance to
combustibles is 1" on all sides of the horizontal run.
Vertical sections of this vent system require a
minimum of 1" clearance to combustibles on all
sides of the pipe.
WARNING
