How is insulation value measured?

• A. Thermal Conductivity (K-Factor)
• B. Heat Flux
• C. Thermal Mass
• D. Density

Answer: (A)

Insulation value is about how resistant a material is to heat flow. The property that directly measures that resistance is thermal conductivity, k. It tells you how much heat moves through a material of a given thickness for a given temperature difference. Lower k means better insulation, and k is expressed in watts per meter-kelvin (W/m·K). The K-factor is just another name for this property. Heat flux is the actual rate of heat transfer through a surface and depends on the temperature difference as well as the material’s k; it isn’t the material property itself. Thermal mass describes how much heat a material can store, not how well it resists transfer. Density is mass per volume and doesn’t directly indicate insulation performance.