As more than 30% of energy consumption is spent on Heat Ventilation and Air conditioning (HVAC) systems, recent advances in daytime passive radiative cooling represent a promising direction to lower down air conditioning energy consumption. Indeed, by using the atmospheric transparency window laying between 8 to 13 μm, a wide range of specific engineered materials called passive radiative coolers can achieve a steady state temperature below ambient with no energy consumption by strongly emitting electromagnetic waves in this specific range of wavelengths and reflecting the incoming solar radiation during daytime. This heat dissipation process to the outer space makes from passive radiative cooling a very promising technology for next generation efficient cooling systems. The fo...[ Read more ]

As more than 30% of energy consumption is spent on Heat Ventilation and Air conditioning (HVAC) systems, recent advances in daytime passive radiative cooling represent a promising direction to lower down air conditioning energy consumption. Indeed, by using the atmospheric transparency window laying between 8 to 13 μm, a wide range of specific engineered materials called passive radiative coolers can achieve a steady state temperature below ambient with no energy consumption by strongly emitting electromagnetic waves in this specific range of wavelengths and reflecting the incoming solar radiation during daytime. This heat dissipation process to the outer space makes from passive radiative cooling a very promising technology for next generation efficient cooling systems. The focus of this thesis is to investigate the performance of an HVAC system based on passive radiative cooling using numerical simulations under different weather conditions. A first step towards real world application being to passively cool down refrigerants below the ambient temperature, experiments have also been led to generate sub-ambient chilled water in the hot and humid climate of Hong Kong using a passive radiative cooling material which evaluates the feasibility of an air-conditioning system based on passive radiative cooling. Finally, the integration of passive radiative cooling with biphilic surfaces for passive atmospheric water harvest as a first step towards passive dehumidification systems for buildings application is presented with a confirmed fabrication method and characterization. An experimental set-up for performance assessment is suggested.