MHSC SB38 - Outside Combustion Air Precautions and Recommendations

SB38 / SB44 Series Woodburning Fireplace
6
87D0057

: The use of outside air for combustion is optional unless required by building codes. It
is only necessary to supply outside combustion air to one side of the fireplace. Use the model
AK4 combustion air kit.
FP1900
OA start collar
8/08
Insulation Ring
Insert Shortest Side of the
Tube through the Fireplace
Outer Wrap to Properly
Seal Against Firebox Wall
and Gasket
Longer Length of the Tube
to Outside

Figure 31
 Secure outside air starting collar to left side of fire-
place with four (4) sheet metal screws provided.
 The starting collar extends through the outer fireplace
jacket and will seal against the firebox wall when secured as
indicated.
FP1900
&0
SECUREOUTSIDEDUCT

 Secure outside duct to starting
collar with duct clamp or screws.
Fireplace Outer Wrap
AK4 Combustion Air
Kit (Shortest Toward
Firebox)
AK4 Mounting Plate
Firebox Insulation Seal
FP1901
FP2229
above basement
1/09
Firestop
Spacer
Duct Extended
to Avoid Joint
Second Floor
To Outside Wall
FP9


8’ Max.
FP2230
OA soffit install
1/09
Chimney
Cap
Firestop
 Do not
take air from attic
spac or garage.
Inlet Grille
in Soffit
(Overhang)
FP30

(Optional Outside Air Runs)