www.desatech.com
118116-01D
5
HEARTH EXTENSION
A hearth extension projecting a minimum of
20" in front of and a minimum of 12" beyond
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using a material which meets the following
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inorganic material having a thermal conduc-
tivity of K=0.84 BTU IN/FT, HR. F (or less) at
1" thick. For example, if the material selected
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following formula would apply:
0.25 x 1.0" = 0.30" thickness required
0.84
Thermal conductivity "K" of materials can be
obtained from the manufacturer or supplier of
the noncombustible material. If hearth exten-
sion is to be covered, use noncombustible
material such as tile, slate, brick, concrete,
metal, glass, marble, stone, etc. Provide
a means to prevent hearth extension from
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and hearth extension with a noncombustible
material (see Figure 3).
FIREPLACE INSTALLATION
Continued
Figure 3 - Hearth Extension
Seal Gap
Fireplace Front
Ember Protector
Fireplace Front
Raised Hearth
Fireplace Front
Elevated
Ember Protector
Ember Protector
Seal Gap
Hearth
Extension
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is to be installed only as shown
in Figure 3.
MANTELS
A mantel may be installed if desired (see
Figure 4). Woodwork such as wood trims,
mantels or any other combustible material
projecting from front face must not be placed
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materials above 12" and projecting more than
1
1
/
2
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STD 211, Sec. 7-3.3.3).
Mantels or any other combustible material
also may come up to the side edge of the
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the projection from front face falls within limit
shown in Figure 4.
12
1
/
4
" Ref.
15" Min.
12" Min.
1
1
/
2
" Max.
3" Nom.
33°
Combustible
Material
Safe
Zone for
Projection of
Combustible
Materials
Fireplace Opening
Upper
Section of
Fireplace
Figure 4 - Mantel Clearances to
Combustible Material
6"
Ref.
VENTING INSTALLATION
OPTIONAL OUTSIDE AIR KIT (MODEL AK4/AK4F)
The installation of an outside air kit should
be performed during the rough framing of
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Outside combustion air is accessed through
a vented crawl space (AK4F) or through a
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with a barometric damper which allow outside
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needed.
