16
Majestic Biltmore Series • SB100 • 4013-303 Installers Manual • Rev H • 08/20
H. Outside Air Kit
Two outside air kits must be used for combustion. Hearth
& Home Technologies recommends you utilize the shortest
duct runs to optimize the performance of the outside air
kits and install a P-trap. See Figure 3.17. The outside air
inlet hoods should be positioned in a manner that will not
allow snow, leaves, etc. to block the inlets. In some instal
-
lations the air duct may need to be run vertically. In such
an installation, a 3 ft (914 mm) height difference must be
maintained from the top of the uppermost chimney section
to the outside air inlet hoods.
NOTE: The maximum length of a 4 inch diameter duct is
20 feet. The duct can be extended up to a maximum of 40
feet by using 6 inch duct. A 4 inch to 6 inch adapter will be
needed. (not included).
NOTE: The minimum cross-sectional area of the 4 inch
inlet hood is 7.0 square inches.
Refer to Figures 3.15 and 3.16 when placing the outside
air inlet hoods.
An outside air kit is installed on each side of the fireplace.
• Cut 4-1/2 in. (114 mm) holes in outside wall to
accommodate air piping.
• Use 4 in. (102 mm) flex (not supplied) to directly connect
outside air to fireplace intake. Insulate the pipe to prevent
frost condensation.
• Use the supplied outside air inlet hoods.
• Seal between the wall and the pipe with silicone to
prevent moisture penetration and air leaks.
• Seal between the outside air inlet hoods and the house
with silicone to prevent air infiltration.
CAUTION! Risk of Cuts/Abrasions.
Wear protective
gloves and safety glasses during installation. Sheet metal
edges are sharp.
CAUTION! Risk of Fire or Asphyxiation! DO NOT
draw
outside combustion air from wall, floor or ceiling cavity, or
enclosed spaces such as an attic or garage.
•
DO NOT
place outside air inlet hood close to exhaust
vents or chimneys. Fumes or odor could be drawn into
the room through the fireplace.
• Locate outside air inlet hood to prevent blockage from
leaves, snow/ice, or other debris. Blockages could cause
combustion air starvation.
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3 ft min. from
top of uppermost
chimney section
to air inlet.
Figure 3.16 Outside Air Inlet Hood Locations
Outlet placed
higher than 3 ft
below the
termination cap
Attic space
Garage or
combustible
liquids storage
Outlet blocked by
snow, leaves, etc.
Clear area
outside
house or in
ventilated
crawl space
YES
NO
NO
NO
NO
Factory-built
fireplace
• Use UL181 Class 1 or Class 0 rigid or flexible ducting.
• Install with short run and add a P-trap which will help
prevent flow of cold air.
• Secure flex duct with screws or wire ties.
Figure 3.15 Outside Air Installation
Typical Outside Air
Installation
Typical CAK Installation
Seal
Seal
24” (610 mm) min.
48” (1220 mm) max.
Note: The pipe
cannot lay on top
of the unit.
4” Duct-Use UL181
Class 0 or Class 1
ducting
Recommend
around 24 inches
for a minimum bend
Figure 3.17 Outside Air Installation with Cold Air Trap
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