The thermo-insulating properties of both perpendicular- and conventional cross-laid lofty nonwoven fabrics, four different types each in terms of fiber fineness, are investi gated using a new static method with a heat flux sensor. The relationship between the thermal conductivity and the material density of all the samples is studied, and the compressive behavior of the materials and changes in thermal resistance with compression are also evaluated. The effects of fiber fineness and material density are examined and discussed as well.