What is effect of porosity on heat conduction?

Porosity significantly affects heat conduction in materials, as increased porosity typically leads to lower thermal conductivity. This occurs because the air or gas-filled voids in a porous material act as thermal insulators, reducing the overall ability of the material to conduct heat. Consequently, highly porous materials are often utilized for insulation purposes, where low thermal conductivity is desirable. However, the specific impact of porosity on heat conduction also depends on factors like the material's composition and the size and distribution of the pores.