Thermal insulation characteristics of textile drapery fabrics

Transmittances of drapery models representing selected levels of the eight independent variables were measured on a standard window equipped with a heat sensor device connected to a computer.

The physical properties of moisture regain, reflectance, thickness, weight, air permeability, porosity and drape of each of the fabrics were measured in order to determine relationships between these properties and the heat transmittance of the drapery.

Single thicknesses of eight drapery fabrics and two lining fabrics were tested for insulation value at two relative humidity levels, 45% and 65%. Analysis of variance showed the following factors to be significant: fiber type, weave openness and relative humidity. Color was not significant.

The four light colored drapery fabrics were tested in layered combinations with a lining fabric at the two relative humidity levels. Two levels of drapery fullness (50% and 100%), three levels of lining fullness (flat, 50% and 100%) and three levels of lining-drapery spatial separations (touching, 1/4 inch and 1/2 inch) were tested. Fabric, lining fullness, drapery fullness, spatial configuration and relative humidity were found to be significant.

Additional analysis revealed several regression models for predicting the insulation value of the draperies. Although many of the factors were found to be significant, variables were eliminated from the models in a stepwise procedure. Analysis showed that 98% of the variation in transmittance in the single layer fabrics could be predicted by relative humidity and air permeability, and that 92% of the variation in transmittance of the multiple fabric configurations could be predicted by relative humidity, air permeability and lining fullness.