Isotherms of adsorption of CO2 on two different glass fibers are measured at 158 and 185 K by the volumetric method. Heats of adsorption are determined. Experimental data are analyzed in terms of the Langmuir model of independent adsorption sites. Distributions of adsorption sites in free energy (not in energy) are determined at two temperatures, and their temperature dependence is discussed. This dependence makes it possible to obtain the entropy and energy distribution of adsorption sites and the relation of entropy to energy for a site. The latter enables one to assess the reliability of the distributions.