Morgan & Company HEARTHSTONE 8470 - Manual (Page 8)

Hearthstone Quality Home Heating Products, Inc. ® Morgan Model 8470 6
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 Thickness R-value
Gypsum or plaster board
1 1
/
2
 0.45
Wallboard, Wonderboard, or
Durock
1
1
/
2

0.20
Ceramic board (Fiberfrax or Micor)
1 1
/
2
 1.10
Nominal solid clay brick
1
1
 0.20
Ceramic wall or floor tile 1 1 /
4
 0.01
Mineral wool insulation
2
1
 3.12
Cement mortar
2
1
 0.20
Horizontal still air 2 * 1
/
8
 0.92
1 According to Intertek Testing Services, Inc.
2 According to ASHRAE Handbook of Fundamentals
1977