Experimental analysis of energy storage performance of phase change materials in horizontal double-glazing applications

In this study, phase change material (PCM) energy storage performance was experimentally investigated for horizontal double-glazing applications. In this context, it was aimed to use PCM for energy storage in horizontal insulating glass applications, and optimize amount of PCM in the glass and the effect of the surface area it occupies on the indoor light level were analyzed. In this regard, the temperature variation in the glass with the amount of PCM was observed and the optimum amount of PCM was evaluated. The experiments were carried out on an insulated test cabin using double-glazed test elements with different PCM ratios as 0 %, 15 %, 30 %, 45 %, and 100 %. An external light source was used to create constant radiation conditions during the experiments and temperature measurements, thermal camera images, as well as light intensity measurements were taken in the test cabin. The results revealed that the increase in the energy storage capacity with the amount of PCM is limited, while the light transmittance decreases continuously due to the solid PCM shading. In other words, as the amount of used PCM increases, the energy storage capacity increases and thermal comfort conditions improve. However, this increase stopped at a certain point and a constant trend was observed. It was concluded that, this situation occurs due to the blocking of the radiation entering the indoor environment and the decrease in the radiation intensity. For the 30 % area ratio, the cooling period was extended by 450 min compared to the reference case, and longer thermal comfort conditions were provided.