Majestic Fireplaces® ODSR Series "A"
COMMON MATERIALS AND FACTORS
MATERIAL | K* | R | MINIMUM |
THICKNESS |
EH2416 |
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(CFM Corporation) 0.458 1.09 | 0.50 in.** |
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Common Brick 5.0 0.10 | 5.46 in.** |
R Value is for 1/2 inch.
*Units of K = BTU/SQ FT/HR/˚F/IN ** Thickness of Listed Material
FP533ADD
Fig. 23 Hearth extension material factors.
WARNING: HEARTH EXTENSION MUST BE IN- STALLED IN ACCORDANCE WITH FIGURE 23 AND MUST NOT COVER THE BOTTOM FRONT OPENING OF THE CIRCULATING MODEL.
Alternate noncombustible materials may be used pro- viding the (total) thermal resistance (Rt value) of the al- ternate material employed is greater than or equal to R
=1.09. Thermal resistance (R) or thermal conductivity (K), may be obtained from manufacturer of the material. Factors are related by the formula K = 1/R.
T = given thickness
R = thermal resistance for a given thickness (T) K = thermal conductivity
Noncombustible material with a lower R value may be used, provided thickness of material is sufficiently greater to maintain an equivalent (total) thermal resis- tance (Rt).
Example of Determining Hearth Extension Equiva- lents
To determine the thickness required for any new mate- rial:
NEW | K of new material (per inch) | Thickness | ||
required = |
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| X | of listed |
thickness | K of listed material (per inch) | material | ||
Example for Common Brick
T (new) = 5.0/0.458 x 0/50 in. = 5.46 in. (new required thickness).
Side View
Wall Covering |
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Noncombus- | 2 x 4 Header | |
tible Decorative | ||
(Do not notch | ||
Facing | ||
at standoffs) | ||
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Seal all cracks between fireplace sur- round and wall materi- als with noncombus- tible material
Noncombustible Decorative Cov- ering
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| Seal crack between | |
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| Hearth Extension |
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| fireplace and hearth | ||||
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| extension with noncom- | |||||
| Insulation |
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| Safety Strips | |
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| Must be overlapped 1/2" | |
FP550 |
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Fig. 24 Sealing gaps.
16 | 20006811 |
