New energy-saving building developed by using polyethylene glycol/halloysite nanotube energy-storage blanket and heat-insulating glass with NaxWO3@SiO2 nano-coating

Abstract

Transparent heat-insulation glass (HIG) with a highly selective light-absorbing coating and an energy-storage blanket (ESB) loaded with phase change materials show considerable potential in reducing building energy consumption. However, the energy-saving effect of a single material is usually not ideal, and the instability of HIG and ESB limits their applications. In this work, HIG with enhanced stability and a form-stable ESB was prepared. The temperature difference between various indoor areas and energy consumption were reduced simultaneously because of the temperature regulation function of the HIG and ESB in the light and dark areas. NaxWO3@SiO2-coated HIG showed excellent daylighting and near-infrared-light-shielding ability with visible light transmittance of 71% and near-infrared light transmittance of 16%, respectively. Moreover, polyethylene glycol/halloysite nanotube composite phase change material with a high enthalpy of 71.1 J/g and a suitable phase change temperature of 27.5 °C was prepared for the form-stable ESB. The test room experiment indicated that the combination of the HIG and ESB (HIG–ESB) reduced the indoor temperature difference from 6.8 °C to 0.9 °C and the maximum temperature by 33–40%. The energy consumption simulation revealed that the ESB can save energy in all selected cities, whereas HIG is only applicable to cities in warm regions. HIG–ESB achieved the highest annual energy-saving rate of 43.9% in Hong Kong. The joint application of the HIG and ESB provides a new strategy for developing passive energy-saving buildings.