TOA Electronics CST-38 - Manual (Page 20)

NOTE: DIAGRAMS & ILLUSTRATIONS NOT TO SCALE. 20
Example: Given that the required “R value” for
a suitable hearth extension used must be equal
to or greater than:
“R” = r x T
L
= 1.19 x 1" = 1.19.
If it is desired to elevate a marble hearth exten-
sion to a level of 5" or more above the floor
surface. What combination of noncombustible
materials can be used to accomplish this?
If common brick is used so that the 3 ¹⁄₂"
dimension is the height, “R” for the common
brick becomes:
“R”
M
= r x T
M
= 0.20 x 3 ¹⁄₂" = .70
Using ¹⁄₂" of mortar to set the brick, “R” for the
mortar is calculated as follows:
“R”
M
= r x T
M
= 0.20 x ¹⁄₂" = .10
A ³⁄₄" marble slab set in ¹⁄₂" mortar covers the
brick, “R” for the marble and mortar becomes:
“R”
M
= r x T
M
= 0.09 x ³⁄₄" = .068
“R”
M
= r x T
M
= 0.20 x ¹⁄₂" = .10
The sum of all “R values” is:
.70 + .10 +. 068 + .10 = .968
This would not be an acceptable combination
of material for the hearth extension since the
total calculated “R value” of the materials used
is under the required “R value” of 1.19. An
additional layer of insulating materials must
be used.
WARNING: THE CRACK BETWEEN THE
FIREPLACE AND THE HEARTH EXTEN-
SION MUST BE SEALED WITH A NON-
COMBUSTIBLE MATERIAL.
WARNING: WHEN INSTALLING THE
HEARTH EXTENSION BE CAREFUL NOT
TO BLOCK THE HEAT-CIRCULATING AIR
INLET GRILL.
WARNING: WHEN INSTALLING HEARTH
EXTENSION IN FRONT OF THE FIRE-
PLACE, THE FIREPLACE MUST BE RAISED
IF HEIGHT OF HEARTH EXTENSION EX-
CEEDS 5 3/4" ABOVE BOTTOM OF FIRE-
PLACE (
FIGURE 59 ).
ACCESSORY PARTS AND COMPONENTS
LIST FOR MODELS CST-38 AND CPF-38
The accessory parts and components shown
on pages 21 and 22 are to be used only with
your CST-38 and CPF-38 fireplace systems.
Separate installation instructions are pack-
aged with all combustion air kits and chimney
terminations.
If you encounter any problems or have ques-
tions concerning the installation or application
of this system, please contact your distributor.
For the name of your nearest distributor call:
LENNOX HEARTH PRODUCTS
1110 West Taft Avenue
Orange, CA 92865
Model Part Number Weight
CST-38 051991 215 lbs.
CPF-38 052011 210 lbs.
Figure 60
“R value” = 1 = r x thickness of material used
k
Figure 61
Maximum Thickness of Hearth Extension
when Fireplace is on the Floor.
5 ⁵⁄₈" *
(143 mm)
Max.
* 5 ¹⁄₈" (130 mm)
If “C” Style Door
Is Used.
Figure 59
8" (203 mm)
11 ³⁄₈"
(289 mm)
30˚
Combustible
Materials Allowed
in Shaded Area
1" (25 mm)
Minimum Distance
to Protected Side Wall
4 ⁵⁄₈"
(118 mm)
18"
(457 mm)
Minimum Distance
to Unprotected Side Wall
Model CST-38
8" (203 mm)
30˚
Combustible
Materials Allowed
in Shaded Area
1" (25 mm)
Minimum Distance
to Side Wall
Model CPF-38
FINISH TO YOUR TASTE
There are a wide variety of “finished looks” for
your CST and CPF fireplace from formal wall
decor with elaborate mantels to rustic wood
paneling or warm brick facings.
Only noncombustible materials like marble,
stone, tile, brick, etc. may overlap the black
front facing, but be careful not to interfere with
the operation of the glass doors. Seal all joints
between the black facing and wall surrounds
to prevent cold air intrusion. Use noncombus-
tible caulking material only to seal the black
metal facing to the surround material on the
finished wall.
Combustibles may also project beyond the
sides of the fireplace opening as long as they
are kept within the shaded areas, as illustrated
in
Figures 60 and 61.