Coefficient of Thermal Conductance (C)

Amount of heat (in Btu) that passes through a specific thickness of a material (either homogeneous or heterogeneous) per hr., per sq. ft., per °F. Measured as temperature difference between surfaces. The "C" value of a homogeneous material equals the "k" value divided by the material thickness: C = k/t (where t = thickness of material in inches)It is impractical to determine a "k" value for some materials such as building paper or those only used or formed as a thin membrane, so only "C" values are given for them.