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  2. R-value (insulation) - Wikipedia

    en.wikipedia.org/wiki/R-value_(insulation)

    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 ...

  3. Heat transfer coefficient - Wikipedia

    en.wikipedia.org/wiki/Heat_transfer_coefficient

    In the walls of buildings the above formula can be used to derive the formula commonly used to calculate the heat through building components. Architects and engineers call the resulting values either the U-Value or the R-Value of a construction assembly like a wall.

  4. Thermal conductance and resistance - Wikipedia

    en.wikipedia.org/wiki/Thermal_conductance_and...

    Calculating thermal conductance is crucial for designing effective heat sinks and cooling systems in electronic devices. Automotive design: Automotive engineers use thermal resistance to optimize the cooling system and prevent overheating in engines and other vehicle components. Evaluating thermal resistance helps in designing engine components ...

  5. Thermal transmittance - Wikipedia

    en.wikipedia.org/wiki/Thermal_transmittance

    To calculate thermal transmittance when there are "bridging" mortar joints it is necessary to calculate two quantities, known as R max and R min. R max can be thought of as the total thermal insulance obtained if it is assumed that there is no lateral flow of heat and R min can be thought of as the total thermal insulance obtained if it is ...

  6. Thermal conductivity and resistivity - Wikipedia

    en.wikipedia.org/wiki/Thermal_conductivity_and...

    The construction industry makes use of measures such as the R-value (resistance) and the U-value (transmittance or conductance). Although related to the thermal conductivity of a material used in an insulation product or assembly, R- and U-values are measured per unit area, and depend on the specified thickness of the product or assembly. [note 2]

  7. Table of specific heat capacities - Wikipedia

    en.wikipedia.org/wiki/Table_of_specific_heat...

    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 ...

  8. Heisler chart - Wikipedia

    en.wikipedia.org/wiki/Heisler_Chart

    These first Heisler–Gröber charts were based upon the first term of the exact Fourier series solution for an infinite plane wall: (,) = = [⁡ + ⁡ ⁡], [1]where T i is the initial uniform temperature of the slab, T ∞ is the constant environmental temperature imposed at the boundary, x is the location in the plane wall, λ is the root of λ * tan λ = Bi, and α is thermal diffusivity.

  9. Heat flux sensor - Wikipedia

    en.wikipedia.org/wiki/Heat_flux_sensor

    Heat flux sensors mounted to building walls or envelope component can monitor the amount of heat energy loss/gain through that component and/or can be used to measure the envelope thermal resistance, R-value, or thermal transmittance, U-value. The measurement of heat flux in walls is comparable to that in soil in many respects.