A Janus smart window for temperature‑adaptive radiative cooling and adjustable solar transmittance

A groundbreaking study published in Nano-Micro Letters presents a novel Janus smart window that achieves dual electro-thermal collaborative control for temperature-adaptive radiative cooling and adjustable solar transmittance. This innovative window, developed by Professor Huai Yang and his team from Peking University and the University of Science and Technology Beijing, demonstrates superior thermoregulation capabilities, making it a promising solution for energy-efficient buildings.

Why This Smart Window Matters

• Dual Control Mechanism: The smart window integrates polymer-stabilized liquid crystal (PSLC) as the active control layer and KCWO-PNIPAM (KPP) as the passive control layer, enabling both active and passive regulation of solar transmittance and radiative cooling.
• Adaptability to Weather Conditions: The window can dynamically adjust its long-wave infrared emissivity (ε_Front) and solar modulation ability (ΔT_sol) to meet diverse seasonal energy-saving requirements.
• Energy Efficiency: Outdoor experiments show that the indoor temperature decreases by 8°C during the day and 5°C at night, with cooling powers reaching 93 W m^-2 during the day and 142 W m^-2 at night.

Innovative Design and Mechanisms

• Active Regulation with PSLC Layer: The PSLC layer allows for dynamic control of sunlight transmittance through applied voltage, ensuring high radiative cooling efficiency and privacy protection.
• Passive Regulation with KCWO-PNIPAM Layer: The thermochromic KCWO-PNIPAM layer provides excellent photothermal conversion and thermal insulation properties, enabling the window to switch between cooling and heating modes based on environmental conditions.
• Electromagnetic Shielding: The smart window also demonstrates effective electromagnetic shielding, addressing concerns about public health and electronic system stability in the 5G era.

Applications and Future Outlook

• Energy Savings: The smart window's ability to regulate solar transmittance and radiative cooling makes it highly effective for reducing HVAC energy consumption in buildings.
• Adaptability: The window's dual control mechanism allows it to adapt to different climates and seasons, making it suitable for a wide range of applications.
• Future Research: Further work may focus on improving the durability and scalability of the smart window technology, as well as exploring new materials and designs to enhance its performance.

Conclusion

The Janus smart window developed by Professor Huai Yang and his team represents a significant advancement in smart window technology. By combining active and passive control mechanisms, this innovative window offers superior thermoregulation capabilities, making it a promising solution for energy-efficient buildings. As research continues to advance, the smart window's potential for reducing energy consumption and enhancing environmental sustainability becomes increasingly clear.

Stay tuned for more groundbreaking advancements from Professor Huai Yang and his team as they continue to push the boundaries of smart window technology!