MHSC SC36A Installation And Operating Manual page 17

COMMON MATERIALS AND FACTORS
MATERIAL
EH2416
0.458
(MHSC)
Common Brick 5.0
R Value is for 1/2 inch.
* Units of K = BTU/SQ FT/HR/˚F/IN
** Thickness of Listed Material
Fig. 24 Hearth extension material factors.
WARNINg: HeARTH eXTeNSION MUST be IN- FP533ADD
Addendum
STALLeD IN ACCORDANCe WITH FIgURe 23 AND
6/1/99 djt
MUST NOT COVeR THe bOTTOM FRONT OPeNINg
8/4/99 changed .2 to .1
OF THe CIRCULATINg MODeL.
one inch to 1/2 inch djt
Alternate noncombustible materials may be used
providing the (total) thermal resistance (Rt value) of the
alternate 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
equivalents
To determine the thickness required for any new mate-
rial:
NEW K of new material (per inch)
required =
thickness K of listed material (per inch)
example for Common brick
T (new) = 5.0/0.458 x 0.50 in. = 5.46 in. (new required
thickness).
7412948
MINIMUM
K* R
THICKNESS
1.09 0.50 in.**
0.10 5.46 in.**
FP533ADD
thickness
X of listed
material
SR/SC Series "A" Woodburning Fireplace
Side View
Wall Covering
Noncombus-
tible Decorative
Facing
Seal all cracks
between fireplace
surround and wall
materials with noncom-
bustible material
Noncombustible
Decorative Cover-
ing
Hearth Extension
Insulation
FP550
Fig. 25 Sealing gaps.
2 x 4 Header
(Do not notch
at standoffs)
Seal crack between
fireplace and hearth
extension with noncom-
bustible material
Safety Strips
Must be overlapped 1/2"
minimum
FP550
BR/BC - SEALING
DETAILS
9/29/97
17