Unit s, c onv er sion f act or s and t abl es – Roxul Industrial Insulation Process User Manual
Page 134

Unit
s, c
onv
er
sion f
act
or
s and t
abl
es
Symbol
Definition
US Unit
Notes
R
Thermal resistance
hr.ft
2
.°F/BTU
linear orientation
hr.ft.°F/BTU
cylindrical orientation
hr.°F/BTU
spherical orientation
r
Thermal resistivity
hr.ft
2
.°F/BTU-in
(conventional unit)
hr.ft.°F/BTU
(alternative)
r
a
Apparent thermal resistivity
hr.ft
2
.°F/BTU-in
-
Heat Energy
BTU
Q
Heat Flow Rate
BTU/hr
q
Heat Flux
BTU/hr.ft
2
T
Temperature
°R or °F
T
s
Absolute Surface Temperature (Rankine)
°R
T
o
Absolute surroundings temperature (Rankine)
°R
i
inner boundary layer
-
subscript
o
outer boundary layer
-
subscript
s
surface
-
subscript
1 … n
internal layer
-
subscript
131