Monessen Hearth NB18 Installation And Operating Instructions Manual page 10

CLEARANCES AND HEIGHT REQUIREMENTS
2¹⁄₂"
Heat
Resistant
Material
Figure 7 -
Minimum Mantel Clearance with No Hood — NB18
Example: A mantel may project from the wall a maximum
FP2256
of 2 ⁄ " at a minimum of 14" above the opening, and a
min. clearance no hood
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2
maximum of 6" at a minimum of 20
12"
10"
8"
6"
2¹⁄₂"
Heat
Resistant
Material
Heater in
Fireplace or
Firebox
Figure 8 -
Minimum Mantel Clearance with Hood — All Models
Example: A mantel may project from the wall a maximum
FP2257
" at a minimum of 8" above the opening, and a
of 2 ⁄
1
2
min clear with hood
maximum of 6" at a minimum of 14
Monessen • NB18/24 Gas Log Set Installation/Owner's Manual • 81D0107 • Rev I • 01/19
10
10"
8"
6"
8" 14" 20¹⁄₂" 24⁵⁄₈" 28"
Heater in
Fireplace or
Firebox
FP2256
⁄ " above the opening.
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2
8" 14¹⁄₂" 18⁵⁄₈" 22¹⁄₂" 26"
Hood
⁄ " above the opening.
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2
Heat
Resistant
Material
Figure 9 -
Minimum Mantel Clearance with No Hood — NB24
FP2260
min mantel 24
Example: The bottom of the mantel may project from the
wall a maximum of 10" at a minimum of 28" above the
opening.
Mantel
Minimum
of 8" Heat
Resistant
Material
Figure 10 - Minimum Mantel Clearance with Hood — NB24
(Example of Unsafe Installation)
FP2259
wrong mantel clearance
Figure 9 is an example of an unsafe mantel installation.
This mantel projects 4" at 8" above the opening, exceeding
the maximum acceptable depth of 2
projects 7" at 14 ⁄ " above the opening, exceeding the
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2
maximum acceptable depth of 6".
If your mantel profile is unsafe, you may either raise the
mantel to an acceptable height OR remove the mantel
NB18/NB24 Gas Log Set
10" or less
28"
12" min.
Heater in
Fireplace or
Firebox
7"
6"
2¹⁄₂"
14¹⁄₂"
4"
8"
Hood
⁄ " The mantel also
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2