Radiative-coupled evaporative cooling: Fundamentals, development, and applications

As global energy demand continues to rise and climate change accelerates, the need for sustainable and energy-efficient cooling solutions has reached a critical level. Conventional air conditioning systems heavily rely on energy-intensive mechanical cooling, which significantly contributes to both electricity demand and greenhouse gas emissions. Passive cooling strategies, particularly radiative cooling (RC) and evaporative cooling (EC), present an alternative approach by harnessing natural processes for temperature regulation. While standalone RC can be affected by weather conditions and EC relies on water availability, Radiative-coupled EC (REC) offers a versatile and sustainable cooling solution suitable for various applications. Here we summarize an overview of the theoretical foundations and mathematical models of REC, encompassing REC by bulk water (REC-BW), REC by perspiration (REC-P), and REC by sorbed water (REC-SW). Moreover, we explore a range of applications, spanning from industrial processes to personal thermal management, and examine the advantages and challenges associated with each REC approach. The significance of REC lies in its potential to revolutionize cooling technology, reduce energy consumption, and minimize the environmental impact. REC-BW can conserve water resources in industrial cooling processes, while REC-P offers innovative solutions for wearable electronics and textiles. REC-SW's adaptability makes it suitable for food preservation and future potable cooling devices. By addressing the challenges posed by REC, including water consumption, textile design, and optimization of bilayer structures, we can unlock the transformative potential of REC and contribute to sustainable cooling technologies in a warming world.