An investigation into the thermal insulation properties of perpendicular laid and conventional cross laid lofty nonwoven fabrics used a new static method with a heat flux sensor to define the relationship between the thermal conductivity and material density of samples manufactured from fibers with different fineness ratings. Thermal conductivity and thermal resistance declined with increasing material density up to a limit before the heat conducted by the fibers themselves became prominent. At a significant range of compression, perpendicular laid fabrics demonstrated a higher degree of compressional resistance in the thickness direction than did the cross laid fabrics due to their fiber orientation. Consequently, the perpendicular laid fabrics retained higher thermal insulation under a given pressure. Fiber fineness affected both thermal conductivity and compressional resistance. Fabrics manufactured from fine fibers exhibited slightly lower thermal conductivity, but significantly lower compressional resistance. 25 refs.