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.\ud \ud 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.\ud \ud 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%.\ud \ud 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

Phase Change Materials in Transparent Building Envelopes: A Strengths, Weakness, Opportunities and Threats (SWOT) Analysis

“…• the geographical distribution of the studies, which also provides an indication of the climatic conditions of the study; • the climatic/seasonal distribution of the studies: winter season (37%) [12][13][14][15][16][17][18][19][20][21][22], mid-season (10%) [14,15,20] and summer (50%) [13][14][15][16][17]20,[23][24][25][26][27][28][29][30][31] season periods; • the most investigated PCM typologies, that have been found to be paraffin wax (60%) [14][15][16]18,19,22,23,[25][26][27][28][29][30][31][32][33][34][35] and salt hydrates (20%) [12,13,…”

“…• in all the papers, the PCM had been macro-encapsulated in containers, that is, glass containers (70%) [12][13][14][15][20][21][22][23][24][25]27,[30][31][32][33][34][35][38][39][40][41], polycarbonate containers (20%) [16,17,19,28,36,42] and aluminium containers (10%) [18,26,29]; • the technologies had predominantly been characterised in outdoor test cells (57%) [14,15,17-22, 24-27,29,31,35] and through laboratory analysis (53%) [12,13,17,20,23,[32][33][34][35][36][37][38][39][40][41][42], while some other studies had been carried out by coupling a modelling activity with an experimental activity (37%) …”

“…So far, the literature has presented different experimental studies on the integration of PCM in glazing units [13,23,24,30,[32][33][34]41,43,44]. Real-scale prototypes of the technology (DGU + PCM) were used to collect data during measurements [25,26,28], and the assembly and the construction of these prototypes were carried out in house laboratories.…”

“…The use of large integrating sphere equipment [33,35] has been necessary to obtain reliable results, due to the high scattering property of the system when the PCM is in a solid …”

Responsive glazing systems: Characterisation methods, summer performance and implications on thermal comfort

“…With regard to the transparent components, not only 4 the thermophysical but also the optical properties of PCMs play an important role in the thermal performance of PCMfilled glazing units (D. Li et al, 2016aLi et al, , 2016b. Therefore, solar and visible properties are needed for a complete and accurate analysis of the behaviour of such components (Goia et al, , 2012bLi et al, 2015) and for a comprehensive evaluation, both thermal and visual aspects should be considered (Giovannini et al, 2017).…”