10 30002314
Dutchwest®
How to Determine if Alternate Floor Protection Materi-
als are Acceptable
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als (i.e. plastics, wood paper products, etc.) are combus-
includes some form of thermal designation such as R-value
(thermal resistance) or k-factor (thermal conductivity).
Procedure:
i. R-value given - no conversion needed.
ii. k-factor is given with a required thickness (T) in
inches:
iii. K-factor is given with a required thickness (T) in
inches:
iv. r-factor is given with a required thickness (T) in
inches: R = r x T
protector:
i. Use the formula in Step 1 to convert values not ex-
pressed as R.
ii. For multiple layers, add R-values of each layer to
determine overall R-value.
3. If the overall R-value of the system is greater than the
acceptable.
EXAMPLE:
thick material with k-factor of 0.84. The proposed alternate
is 4" brick with an r-factor of 0.2 over 1/8" mineral board
with a k-factor of 0.29
value:
Step b: Calculate R of proposed system.
4" brick of r = 0.2, therefore:
Rbrick = 0.2 x 4 = 0.8
1/8" mineral board of k = 0.29, therefore
Rmineralboard = x 0.125 = 0.431
Rtotal = Rbrick + Rmineralboard = 0.8 + 0.431 = 1.231
Step c: Compare proposed system Rtotal of 1.231 to speci-
than required, the system is acceptable.
Fireplace Installations
allow for either top exit or rear exit installations.
You may install your Dutchwest Model 2477 in an exist-
standard legs attached.
-
-
bustible" requirement because the brick or concrete hearth
heavy wooden framing as in Figure 13. Because heat
passes readily through brick or concrete, it can easily pass
a heater on a combustible hearth without legs. Standard
leg installations must include the bottom heat shield. The
freestanding installations.
Floor Protection for Fireplace
Installations with Standard Legs
Fireplace installations with the standard legs and the bot-
an approved 7/8" (22mm) noncombustible hearth pad with
K = 0.84 BTU/in ft2hr. °F or equivalent material with an
R-value of at least 1.04 (Refer to "How to Determine if Al-
ternate Floor Protection Materials are Acceptable" section)
/ 457 mm in Canada] from the front of the stove and from
(203 mm) in Canada] from the right side and rear. It must
also provide protection beneath any horizontal runs of the
chimney connector, including 2" to either side.
Many raised hearths will extend less than the required
distance from the front of the heater when it is installed.
above, must be added to extend the hearth 16" (406 mm)
-
tection.
requirements to the side walls, side decorative trim, and
Installation Clearances" in this section.
REMINDER- FIREPLACE INSERT INSTALLATIONS
WITHOUT LEGS ARE PERMISSIBLE ONLY IF THE
HEARTH IS COMPLETELY NONCOMBUSTIBLE,
SUCH AS UNPAINTED CONCRETE OVER EARTH.
R = x T
1
K x 12
R = x T
1
k
R = x T = x 0.875 = 1.04
1
k
1
0.84
1
0.29
R =
(ft2)(hr)(°F)
Btu
k = = K x 12
(Btu)(in)
(ft2)(hr)(°F)
(Btu)(ft)
(ft2)(hr)(°F)
K =
r = (ft2)(hr)(°F)
(Btu)(in)
1
k
