Passive daytime radiative cooling (PDRC) is an emerging energy conservation technology that spontaneously cools a surface by reflecting solar radiation and emitting excess heat to the cold space through the infrared atmospheric transparency window. A facile strategy to fabricate robust passive daytime radiative coolers based on thermally insulating and spectrally selective composite aerogels are demonstrated. The composited aerogels are constructed by P(VdF-HFP) matrix with abundant micrometer-scale air voids inside and surface modified chopped glass fibers randomly distributed in the porous polymeric matrix. Glass fibers act as skeleton are beneficial for enhancement of the rigidity, compressive strength, and flame retardancy of aerogels to satisfy practical PDRC applications. With a glass fiber mass ratio of 20 %, the aerogel can reach a high average solar reflectance of 0.951 and a high long-wave infrared (LWIR) emissivity of 0.954. By performing rooftop measurements, temperature decrease up to 8.05 °C is experimentally achieved under a high solar radiation (∼946 W m⁻²) at midday time (12:00–14:00). The promising cooling performance comparable to those of state-of-the-art radiative coolers is attributed to the efficiently scattering ability of sunlight by abundant air voids, and the high thermal insulation property to weaken parasitic heat gain from the ambient air.

被动式白天辐射冷却（PDRC）是一种新兴的节能技术，它通过反射太阳辐射并通过红外大气透明窗将多余的热量散发到冷空间来自发冷却表面。展示了一种基于隔热和光谱选择性复合气凝胶制造坚固的被动日间辐射冷却器的简便策略。复合气凝胶由 P(VdF-HFP) 基体构成，内部具有丰富的微米级空隙，表面改性的短切玻璃纤维随机分布在多孔聚合物基体中。玻璃纤维作为骨架有利于提高气凝胶的刚性、抗压强度和阻燃性，以满足实际的 PDRC 应用。玻璃纤维质量比为 20%，气凝胶可以达到 0.951 的高平均太阳反射率和 0.954 的高长波红外 (LWIR) 发射率。通过进行屋顶测量，在高太阳辐射（~946 W m⁻² ) 在中午时间 (12:00–14:00)。与最先进的辐射冷却器相媲美的有希望的冷却性能归因于大量空气空隙对太阳光的有效散射能力，以及降低环境空气寄生热增益的高隔热性能。