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The energy shortage crisis is one of the main challenges facing human society. Energy storage blanket (ESB) based on phase change material (PCM) and transparent heat-insulating glass (HIG) based on selective light-absorbing materials show great potential in regulating temperature and reducing building energy consumption. However, the stability of ESB and HIG is insufficient, and there is often a substantial indoor temperature difference when ESB and HIG are applied alone. In this research, stability-enhanced HIG and ESB were prepared. The oxidation and the decline in the heat insulation ability of HIG in air were solved by coating SiO 2 film on the surface of K x WO 3 nanoparticles. The low thermal conductivity and the deformation during the phase change process of ESB were solved by encapsulating PCM with expanded graphite. The combined use of HIG and ESB (HIG-ESB) reduces the temperature difference in the test room from 5.9 to 0.5 °C and the maximum indoor temperature from 50.5–56.4 °C to 28.5–28.9 °C. The energy-saving rates of ESB, HIG, and HIG-ESB in different climatic regions of China are evaluated by numerical simulation. The results show that ESB can save energy in all regions, while the HIG increases energy consumption in cold areas and can achieve a stronger energy-saving effect than ESB in mild areas such as Hong Kong and Changsha. [Display omitted] • The stability of potassium tungsten bronze was improved by coating SiO 2 film. • The indoor temperature difference of the test room decreased from 5.9 °C to 0.5 °C. • The maximum temperature of the test room can be reduced by 49%. • An annual energy-saving of 29.7% in Hong Kong was achieved from the simulation. [ABSTRACT FROM AUTHOR]

Building energy consumption is influenced evidently by solar radiation. To achieve a stable indoor temperature by minimizing the heat fluctuations resulted from solar radiation, latent heat thermal energy storage systems with phase change materials (PCMs) in building envelope have been studied. Though inorganic PCMs have promising potential applications among all kinds of PCMs, the supercooling and segregation are the major issues which have restricted their practical applications. The purpose of this study is to lessen the supercooling degree of an industrial grade PCM (CaCl 2 ·6H 2 O) by using a nucleating agent - flake graphite. A super absorbent polymer (SAP) was also used as a thickener to prevent segregation of CaCl 2 ·6H 2 O during phase transition. The combined method of thermogravimetric analysis/differential thermal analysis (TGA-DTA) was firstly proposed to evaluate the segregation of inorganic PCM innovatively. The results showed that using 0.5 wt% flake graphite not only eliminated the supercooling of CaCl 2 ·6H 2 O, but also improved its thermal conductivity for better thermal performance. The results of Fourier-transform infrared spectroscopy (FT-IR) and scanning electron microscope (SEM) demonstrated that the flake graphite did play an important role on the crystallization of CaCl 2 ·6H 2 O. Numerical simulation demonstrated that using modified CaCl 2 ·6H 2 O within walls of buildings in Hong Kong and Changsha are economically feasible with the payback periods of 18.3 years and 8.4 years respectively. Image 1 • The supercooling degree of CaCl 2 ·6H 2 O can be reduced to less than 1 °C with the addition of 0.5 wt% flake graphite. • The addition of 25 wt% SAP can eliminate the segregation of CaCl 2 ·6H 2 O. • The combined method of TGA-DTA can evaluate the segregation of CaCl 2 ·6H 2 O effectively. • Using modified CaCl 2 ·6H 2 O in buildings is economically feasible with the payback period of 15 years. [ABSTRACT FROM AUTHOR]