Characterization of the optical properties of a PCM glazing system

Abstract The optical char acteristics of an advan ced glazin g sy stem are p resented in this p ap er. The investigated glazin g sy stem is based on the incorp oration of a p araffin-based Phase Change M aterial (PCM) into a transp arent comp onent, made of two extra-clear glass p anes and a cavity where the PCM lay er is p laced. Due to the highly scattering p rop erty of the sy stem (when the PCM is in solid state), the use of a lar ge integr ating sp here equip ment (75 cm diameter) is necessary to obtain reliable results. The sp ectral transmission, reflection and absorp tion coefficients of the PCM glazin g sy stem are measured b etween 400 and 2000 nanometers, and the integr ated valu es are calcu lated accordin g to the relevant standards. The optical p rop erties are determined with a maximu m relative error of 4% (on the sum of the transmission, reflection and absorption coefficients), when the PCM lay er is either in comp lete solid state or liqu id state. The average error for all the op tical p rop erties is 2%. Different thicknesses of the PCM lay er are used in order to assess the dep endency of the optical p rop erties on the PCM lay er thickness. The angular dep endency is also investigated for beam angle up to 45 deg.