Investigations on thermal and optical performances of a glazing roof with PCM layer

Abstract

Summary The thermal and optical performances of a roof in a building containing phase change material (PCM) were investigated in this paper. The glazing roof model consists of two layers of glass and one layer of PCM. The purpose of filling the roof structure with PCM is to utilize the solar energy efficiently. The effectiveness of thermal and optical performances of the roof PCM system was determined by analyzing the heat flux and temperature at the indoor surface with different absorption coefficients and refractive index of PCM in solid and liquid states. The results show that the absorption coefficients and refractive index of solid and liquid PCMs have both effects on thermal performance in the roof PCM system. Of all the thermal performances, the effect on internal temperature, temperature lag, and total transmitted energy is smaller and the effect on solar transmittance and transmitted solar energy is bigger. The absorption coefficients have the opposite effect with the refractive index on interior temperature lag. Considering the indoor daylight, increasing the refractive index and absorption coefficient of liquid PCM is a better method to better the thermal performance of a roof PCM system. Copyright © 2017 John Wiley & Sons, Ltd.

Characterization of novel shape‐stabilized phase change material mortar: Portland cement containing Na 2 SO 4 ·10H 2 O and fly ash for energy‐efficient building

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Life cycle analysis (LCA) and life cycle cost analysis (LCCA) of phase change materials (PCM) for thermal applications: A review

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“…More specifically, PCM can be integrated into different parts of the building, either in transparent or in translucent elements, to reduce its cooling and heating loads while its successful incorporation depends on a number of factors: the local climatic conditions, the building design and orientation, the equipment selection, the type and quantity of PCM used, the encapsulation method, the phase change temperature and the way the PCM is charged/ discharged, the location of PCMs in the building structures, not to mention the utility rate policy, the occupancy schedule, and the control system in the building. [16][17][18] Over the past few years, several reviews have been written on PCMs and their use in buildings, which is an indication of the increasing interest in PCMs worldwide. 11,12,15,[19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34] However, there are still some difficulties regarding the effective, reliable, and practical application of this technology given that most of the existing studies related to PCMs are based on numerical simulations, prototype experiments, or both, while applications in real buildings, although increasing, are still considered relatively inadequate to draw definitive conclusions or guidelines.…”