Temperature-adaptive structure with angularly asymmetric emission for thermal management on building vertical surfaces

The high solar reflectance of radiative coolers increases winter heating demand, and their fixed-angle emission ignores complex radiative exchange with the ground and surroundings. Here, a temperature-adaptive angularly asymmetric (TAAS) structure with angularly asymmetric emission and dual-band spectral regulation is developed to enable all-season thermal management. The structure adopts a fin-like geometry to realize angularly asymmetric emission. Integrating shape memory alloys (SMAs) and thermochromic microcapsules (TCMs) to achieve independent yet coordinated regulation of mid-infrared radiation and solar spectrum. In hot weather, an upward equivalent emissivity of 0.36, a downward equivalent emissivity of 0.07 and a high solar reflectance (0.91) can be achieved. While in cold weather, a lower equivalent emissivity of 0.13 and higher solar absorption can be realized (0.43). Compared to PDRC film, the TAAS structure enables a temperature decrease of approximately 2 °C in hot weather and a temperature increase of around 5 °C in cold weather. Our design can significantly reduce year-round energy consumption by 1.4–6.3 % and outperforms conventional building envelopes under various weather conditions. This structure advances the concept from static radiative cooling to adaptive thermal management, offering a practical solution for all-season thermal management on building vertical surfaces.