American Energy Systems Catalytic BBF - Manual (Page 23)

23
FIGURE 8: FLOOR PROTECTOR DIMENSIONS
MODEL BBF B R
G 8 8 8
H 18 18 16
I 8 8 3
TABLE 7: MINIMUM DIMENSIONS OF FLOOR PROTECTOR (in inches)
2. If a floor protector, different from the tested floor protector, is to be used, it must meet or exceed the requirements of
the listed R-value of the tested floor protector. To convert alternate floor protectors to their respective R value use the
following procedures:
a. Convert floor material specification to R-value.
i. R-value is given – no conversion is required.
ii.
k-factor is given with required thickness (T) in inches: R = (1/k) x T.
iii. C-factor given: R = 1/C.
b. Determine the R-value of the proposed alternate floor protector.
i. Use the formulas provided in STEP 2 to convert values not expressed as “R.”
ii.
For multiple layers of material, add each R-value of each layer to determine the materials overall R-
Value.
c. If the overall R-value of the alternate material is greater than the tested material defined in STEP 1, then the
alternate floor protection is acceptable.
d. EXAMPLE:
i. The tested material was 3/8 inch thick with a k-factor of 0.85.
ii.
The R-value of the tested material was R = (1/0.85) x 3/8 = 0.44.
iii. Suppose the tested material is to be replaced by 4-inch brick material with a C of 1.25.
iv. The R-value of the alternate brick material is R = (1/1.25) = 0.80. Since the R-value of the alternate brick
material [R = 0.80] is greater than the tested material’s R-value [R = 0.44] then the alternate material is acceptable
for use in the specific application.
3. Listed Floor Protector Definitions:
b. Thermal Conductance = C = Btu/(hr)(ft
2
)(
O
F) = W/(m
2
)(
O
K)
c. Thermal Conductivity = k = (Btu)(inch)/(hr)(ft
2
)(
O
F) = W/(m)(
O
K) = Btu/(hr)(ft)(
O
F)
d. Thermal Resistance = R = (ft
2
)(hr)(
O
F)/Btu = (m
2
)(
O
K)/W
e. HEARTH EXTENSIONS must have an R-value greater than to ensure proper combustible floor protection.