HearthStone Morgan 8470 Owner's Manual page 8

Floor protector's come with various types of
specifications. To convert a floor protector's specification
to an R-value, do one of the following:
•
If the R-value is given, use that value—no
conversion is needed.
•
If a K-factor is given with a required thickness
(T) in inches, use this formula: R-value = 1/K x
T
•
If a C-factor is given, use the formula: R-value =
1/C
To determine the R-value of the proposed alternate floor
protector:
•
Use either the K-factor or the C-factor formula
explained above to convert specifications not
expressed as R-values.
•
For multiple layers of floor protectors, simply
add the R-values of each layer to determine the
overall R-value of the layers.
If the overall R-value of your setup is greater than the
R-value of the specified floor protector, then your setup is
acceptable.
Noncombustible Material
Gypsum or plaster board
Wallboard, Wonderboard, or
1
Durock
Ceramic board (Fiberfrax or Micor)
1
Nominal solid clay brick
1
Ceramic wall or floor tile
2
Mineral wool insulation
2
Cement mortar
2
*
Horizontal still air
1
According to Intertek Testing Services, Inc.
2
According to ASHRAE Handbook of Fundamentals
1977
HearthStone Quality Home Heating Products Inc ®
Thickness
1 "
1
/
2
"
1
/
2
1
"
1
/
2
1"
1 "
/
4
1"
1"
1 "
/
8
R-value
0.45
0.20
1.10
0.20
0.01
3.12
0.20
0.92
7
Morgan Model 8470