FACT #1: R-value is the measurement of a material's ability to stop heat transfer.
FACT #2: The R-values of reflective insulation and mass insulation are based on the same fundamental equation: The ability to stop heat transfer.
FACT #3: Reflective Insulation is a system that reduces the transfer of heat across air space by the use of two surfaces having high thermal reflectance and low emittance (typically metalized film or aluminum) + an inner substance + trapped airspaces.
FACT #4: The R-value of reflective insulation is the measurement of the system rather than a measurement of just the product. Measuring the R-value of the system (a real-world application) is a truer measurement vs. a measurement of the product only. For example, what good is the posted R-value of fiberglass given that once installed in an environment that includes any moisture it loses R-value? Virtually all real-world environments include some humidity. Unlike fiberglass the R-value of Prodex Total insulation is NOT affected by humidity.
FACT #5: Prodex Total insulation 5mm has an R-value of 16.
The R-value was measured under the real-world parameters of:
24-inch on center 2" x 6" wood assembly. Roof application. Test Method ASTM 1116. Airspace of 2.64 inch on each side of product. Heat flow direction down.
13/64 inch (approx. 3/16") - 5mm closed cell polyethylene foam covered on both sides with .0012 inch (0.03mm) aluminum foil facing.