Desa (V)B36 Owner's Operation And Installation Manual page 5

HEARTH EXTENSION
A hearth extension projecting a minimum of
16" in front of and a minimum of 8" beyond
each side of fireplace opening is required to
protect combustible floor construction in front
of fireplace. Fabricate a hearth extension
using a material which meets the following
specifications: a layer of noncombustible,
inorganic material having a thermal conductiv-
ity of K=0.84 BTU IN/FT, HR. F (or less) at 1"
thick. For example, if material selected has
a K factor of 0.25, such as glass fiber, the
following formula would apply:
0.25 x 1.0" = 0.30" thickness required
0.84
Thermal conductivity "K" of materials can be
obtained from manufacturer or supplier of
noncombustible material. If hearth extension
is to be covered, use noncombustible mate-
rial such as tile, slate, brick, concrete, metal,
glass, marble, stone, etc. Provide a means
to prevent hearth extension from shifting and
seal gap between fireplace frame and hearth
extension with a noncombustible material
(see Figure 3).
WARNING: Hearth extension
is to be installed only as shown
in Figure 3.
109034-01M
FIREPLACE INSTALLATION
Continued
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Fireplace Front
Ember Protector
NO
Do Not Block Louver
Fireplace Front
Elevated
Ember Protector
Hearth Extension, Circulating Modes
Fireplace Front
Ember Protector
Fireplace Front
Raised Hearth
Ember Protector
Fireplace Front
Elevated
Ember Protector
Hearth Extension, Noncirculating Models
Figure 3 - Hearth Extension
Seal Gap
Hearth
Extension
Seal Gap
Seal Gap
Hearth
Extension
Seal Gap
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