Radiative Cooling

Radiative cooling is a natural process whereby surfaces dissipate heat by emitting infrared radiation, particularly through the atmospheric transparency window, a spectral range where the Earth’s atmosphere is transparent to certain wavelengths of infrared radiation. This mechanism enables the Earth to cool down by radiating heat into outer space. However, the presence of greenhouse gases, such as carbon dioxide, water vapor and methane, hampers this cooling process by making the atmosphere more opaque to infrared radiation, thereby trapping heat and contributing to global warming.

At our lab, we are dedicated to advancing the understanding and application of radiative cooling technologies. Our research is focused on several critical areas to enhance the efficiency and practicality of radiative cooling systems

  1. Radiative Coolers for Humid Conditions: One of the major challenges in radiative cooling is its reduced effectiveness in humid environments. By exploring angularly and spectrally selective thermal emitters, our lab develops radiative coolers that can operate efficiently under high humidity. 
  2. Development of Passive Radiative Cooling-Based Air Conditioning Systems: We are working on creating air conditioning systems that utilize passive radiative cooling. One of the main challenges of these systems is their efficiency particularly in terms of the area covered by radiative coolers. 
  3. Vertically installed radiative coolers: To increase the surface area covered by radiative coolers, we are investigating thermal emitters capable of radiating efficiently towards the zenith while being vertically installed on walls or windows. These radiative coolers require exploring new photonic designs with asymmetric radiation.
  4. Feasibility of Global Cooling Through Radiative Cooling: Beyond localized applications, our research also explores the potential of radiative cooling to contribute to global cooling efforts. We are investigating large-scale implementations that could enhance the Earth’s overall heat dissipation capacity. This initiative involves developing new designs that promise large area and efficient cooling that can be deployed on a planetary scale.