Minggu, 26 Mei 2013

PERBANDINGAN R-VALUE BAHAN INSULASI SECARA UMUM

PERBANDINGAN R-VALUE BAHAN INSULASI SECARA UMUM

Polyurethane is a highly efficient insulator. For every two inches of polyurethane foam, this much of another insulating material would be needed for equivalent insulatin performance: "U-value" (or U-factor) measures heat transfer through insulation or a building component over time, under standardized conditions. Since it's an inverse measurement to R-value (R = 1/U), a low U-value number indicates a superior insulator.
Insulation Material   R-value Range    Thickness to match 2"
Polyurethane Foam R 5.6 - 8.0 /inch 2 inches
Polystyrene R 3.8 - 5.0 / inch 3.1 inches
Cellulose R 3.6 - 3.8 / inch 3.7 inches
Rock & Glass wool R 2.9 - 3.8 / inch 4.0 inches
OSB Sheathing R 1.25 / inch 10.9 inches
Plywood R 1.25 / inch 10.9 inches
Concrete Block R 0.25 / inch 54 inches
Brick R 0.2 / inch 68 inches
Sprayed Polyurethane Foam (SPF) will have an R-Value of 7.14 when it is newly installed. After it ages a few months, the R-Value will reduce to somewhere around 6.88. The C-value (C) is a measure of the Thermal Conductance of the material and is the reciprocal of R, or
R-Value
C is determined only when the Thermal Conductivity (k) of a material is known.
R-Value
Thermal Conductivity is the measure of the amount heat that will be transmitted through a one inch (1") thick piece of homogenous material, one square foot (1 ft.2) in size, in one (1) hour, when there is a one degree Fahrenheit (1° F) temperature change. The equation for "k" is:R-Value-BTU

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