State the Properties of thermal insulating materials.
Properties of thermal insulating materials:
1) Thermal insulating should be bio resistant and dry.
2) Thermal resistant should be chemically resistant and fire proof.
3) Thermal resisting material should have bulk density below 600Kg/m3 .
4) Thermal insulating material should have more pores as the entrapped air or any other gases within the pores decreases the thermal conductivity of material.
5) The pores in thermal insulating material should be closed so that water vapor does not enter in the material.
6) With increase in the moisture content in the material, the coefficient of thermal conductivity rises greatly.