High emissivity surface to reduce insulation thickness
Keeping the surface of an insulation material above the dew-point temperature is key to stopping condensation. Insulation thickness and thermal conductivity play major roles but, when it comes to controlling the surface temperature of insulation, no material property is more important than the surface emissivity.
Surface emissivity measures the potential of a material to emit energy in the form of thermal radiation. Black, non-reflective, surfaces with a high emissivity finish are well suited to keeping the surface temperature above that of the dew-point. Relatively small thicknesses of insulation can be used to reliably prevent condensation if the insulation material presents a high emissivity surface finish.