Optimizing Insulation and Geometrical Designs for Enhanced Sub-Ambient Radiative Cooling Efficiency

Radiative cooling, exploiting the atmospheric transparency window (8-13 μm), offers a passive method for achieving sub-ambient cooling by emitting thermal radiation to outer space. While promising, current systems often suffer from parasitic heat gains, limiting their efficiency. Our research explores innovative methods to minimize these heat gains and isolate radiative cooling systems from convective and conductive heat transfer. We investigate various insulation strategies, including multi-layer reflective barriers, vacuum-sealed environments, and geometrical designs such as flat and parabolic structures. Our materials include aluminum foil and aluminized polyethylene terephthalate (PET), chosen for their reflective properties and broad accessibility. These approaches aim to optimize the directionality of thermal radiation while shielding the system from atmospheric interference. By systematically evaluating different insulation configurations, material combinations, and geometric designs, we aim to quantify their impact on cooling performance. Preliminary results suggest a potential sub-ambient temperature reduction of 6-12°C under sunlight. This research seeks to bridge the gap between theoretical cooling limits and practical applications.