For most materials, the amount of heat conducted varies (usually non-linearly) with temperature.
Note that for gases in usual conditions, heat transfer by advection (caused by convection or turbulence for instance) is the dominant mechanism compared to conduction.
This table shows thermal conductivity in SI units of watts per metre-kelvin (W·m−1·K−1).
Some measurements use the imperial unit BTUs per foot per hour per degree Fahrenheit (1 BTU h−1 ft−1 F−1 = 1.728 W·m−1·K−1).
Numerous variations of all of the above and various other methods have been discussed by some G. K. White, M. J. Laubits, D. R. Flynn, B. O. Peirce and R. W. Wilson and various other theorists who are noted in an international Data Series from Purdue University, Volume I pages 14a–38a.
Ki-iti Horai, Thermal conductivity of Rock Forming minerals, Journal of Geophysical Research, Volume 76, Issue 5, pages 1278 — 1308, February 10, 1971.
The TPRC recommended values are for well annealed 99.999% pure copper with residual electrical resistivity of ρ0=0.000851 μΩ⋅cm.
Errata: Contrary to what they say the formula of Bonales and Sanz cannot be fitted to their data and also it is not consistent with the results of Choi and Okos since their formula is a typo and also Choi and Okos did not cook up a linear function to start with.
Apart from a thermal conductivity a boiler company also has an interface heat transfer coefficient Q and also some Kurganov has posted this simplification that water flowing in tubes has Q ≈ 500 - 1200 W/(m2K).
[32] For those who may already see reasons to learn more about the thermal conductivities of the soils it is free from the Army Cold Regions Research and Engineering Laboratory.
Some recent developments include Zirconia fibrous thermal insulation for temperatures up to about 2000 Kelvins.