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This is a list of insulation materials used around the world. Typical R-values are given for various materials and structures as approximations based on the average of available figures and are sorted by lowest value. R-value at 1 m gives R-values normalised to a 1 metre (3 ft 3 in) thickness and sorts by median value of the range.
The R-value is the building industry term [3] for thermal resistance "per unit area." [4] It is sometimes denoted RSI-value if the SI units are used. [5] An R-value can be given for a material (e.g., for polyethylene foam), or for an assembly of materials (e.g., a wall or a window). In the case of materials, it is often expressed in terms of R ...
Note that the especially high molar values, as for paraffin, gasoline, water and ammonia, result from calculating specific heats in terms of moles of molecules. If specific heat is expressed per mole of atoms for these substances, none of the constant-volume values exceed, to any large extent, the theoretical Dulong–Petit limit of 25 J⋅mol ...
Energy densities table Storage type Specific energy (MJ/kg) Energy density (MJ/L) Peak recovery efficiency % Practical recovery efficiency % Arbitrary Antimatter: 89,875,517,874: depends on density: Deuterium–tritium fusion: 576,000,000 [1] Uranium-235 fissile isotope: 144,000,000 [1] 1,500,000,000
Higashi anomalies: The very high c values that are labeled as thermal conductivities in table III on page 100 would roughly fit the thesis of the paper if they came with lower orders of magnitude. The way that the dry soils get a lot lighter between Table I on page 99 and table IV on pages 102-3 is eventually explained by the fact that Table I ...
Relative permittivities of some materials at room temperature under 1 kHz; Material ε r; Vacuum: 1 (by definition) Air: 1.000 589 86 ± 0.000 000 50 (at STP, 900 kHz), [1]: PTFE/Teflon: 2.1 ...
Thermal insulance (R-value) is a measure of a material's resistance to the heat current. It quantifies how effectively a material can resist the transfer of heat through conduction, convection, and radiation.
While R-values "per inch" are common in the U.S., the table doesn't make much sense for SI units because in this table it's RSI per 25.4 mm. A better way to display the information is by conductivity, which is per unit length. If we want to maintain this as a list of R-values then each material should specify the thickness and density.