Chronology | Current Month | Current Thread | Current Date |
[Year List] [Month List (current year)] | [Date Index] [Thread Index] | [Thread Prev] [Thread Next] | [Date Prev] [Date Next] |
Correction: Units of R are F-deg (of temp difference) per (BTU/hour/sq-ft)
So R-19 means that a difference of 19 Fahrenheit degrees across the
surfaces
of this material will produce a transfer rate of 1 BTU/hour per square foot
of surface area.
R-30 is better because it requires a 30 degree difference to produce the
same energy transfer rate.
Note that this may not reflect the over-all (internal air to external
environment) transfer, due to air boundary layers, convection , radiation,
etc.