Mastic Spark Modern Fires 91P - Manual (Page 14)

14 L100001 15
VENT 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.
You may use up to three 90° elbows in this vent configuration. See
Horizontal Termination Configurations on pages 19 and 20.
FOR VERTICAL TERMINATION
Measure the distance from the fireplace floor to the ceiling. Add the ceiling thickness, the vertical rise in an attic or second story,
and allow for sufficient 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, firestops are required at each floor level. If an offset is needed in the attic, additional pipe and elbows
will be required.
You may use a chase with a vent termination with exposed pipe on the exterior of the house. See 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 flue gas exhaust.
Certain limitations apply to vent configurations 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.
Never run the vent pipe level or downward.
This may cause excessive temperatures which
could cause a fire.
WARNING
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.
NOTICE
Treatment of firestops 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.
NOTICE