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FLOOR PROTECTOR
The stove must be placed on solid concrete, solid masonry, or when installed on a combustible floor, on a
Type 2 floor protector listed to standard UL 1618 with a minimum R value of 3.0 and a minimum thickness of
1” or equivalent. The floor protector is required to provide heat, live ember, and ash protection and must be
of a non-combustible, continuous solid surface to protect against infiltration of live embers and ash. For UL
Listed floor protectors, refer to manufacturers instructions for installation directions. Manufacturers of listed
floor protectors include Imperial Metal Products and Hy-C among others. To calculate R-Values for alternative
methods, see below for calculation methods.
Alternate materials may be rated with C-factor (Thermal Conductance) or k-factor (Thermal Conductivity)
ratings which must be converted to R-value to determine if the alternate material meets the tested
requirements. The following instructions provide the proper information and formulas for conversion to R-value.
To determine if alternate materials are acceptable follow this sequence.
1. 1. Convert material specifications to R-value:
a. R-value given — no conversion necessary
b. k-factor is given with a required thickness (T) in inches: R = 1/k x T
c. C-factor is given: R = 1/C
2. 2. Determine the R-value of proposed alternate floor protector:
a. Use formulas in step 1 above to calculate R-value of proposed material(s).
b. For multiple layers, add R-values of each layer to determine overall R-value.
1. 3. If the overall R-value of the floor protector system is equal to or greater than the floor protector
specifications given, the alternate is acceptable.
Definitions:
Thermal conductance (C) =
=
Thermal conductivity (k) =
=
=
Thermal resistance (R) =
=
Example:
The specs of floor protector material should be 3/4-inch thick material with a k-factor of 0.84. The proposed
alternative material is 4” brick with a C-factor of 1.25 over 1/8-inch mineral board with a k-factor of 0.29.
Step 1:
Convert specs to R-value.
R = 1/k x T = 1/0.84 x 0.75 = 0.893 System must have a R-value of 0.893 = Rspecs
Step 2:
Calculate R-value of individual components
4” Brick with C-factor = 1.25. R = 1/C = 1/1.25 = 0.80 = Rbrick
1/8-inch (0.125”) mineral board with k-factor = 0.29. R = 1/0.29 x 0.125 = 0.431 = Rmin.brd.
Step 3:
Add R-values of components to get total R-value of system
Rmin.brd = 0.80 + 0.431 = 1.231 = Rsystem
Step 4:
Compare Rsystem to Rspecs
Rsystem = 1.231 is larger than Rspecs of 0.893. System R-value exceeds the required specifications and
therefore is an acceptable alternative.
BTU
(hr)(ft²)(°F)
W
(m²)(°K)
(Btu)(inch)
(hr)(ft²)(°F)
W
(m²)(°K)
BTU
(hr)(ft²)(°F)
(hr)(ft²)(°F)
BTU
(m²)(°K)
W
Summary of Contents for VG180L
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