Toward the Scaling up of Daytime Radiative Coolers: A Review

Abstract

AbstractDaytime Radiative Cooling (DRC) is a highly effective passive cooling technique that holds great potential for enhancing energy efficiency and promoting decarbonization. Several Daytime Radiative Coolers (DRCs) are reported in the literature to highly reflect shortwave radiation and emit thermal radiation, either specifically in the Atmospheric Window (AW) wavelengths (8–13 µm) (Selective DRCs) or in both AW and non‐AW wavelengths (Broadband DRCs). This review presents the advancements in the six key categories of DRCs identified in the literature based on their design characteristics: i) multilayer DRCs, ii) metamaterial DRCs, iii) randomly distributed particle DRC structures, iv) porous DRCs, v) colored DRCs, and vi) adaptive DRCs. The review discusses their main attributes in terms of their demonstrated thermo‐optical performance. Research gaps include the need for real‐life studies to investigate scaling up DRCs in the built environment and their effects on indoor thermal comfort and air temperature reduction. Finally, an eight‐step feedback‐loop scheme is proposed to establish efficient design and implementation protocols for DRC materials in the built environment.