Tunable daytime passive radiative cooling based on a broadband angle selective low-pass filter
Nanoscale Advances just published one of our newest works on: “Tunable daytime passive radiative cooling based on a broadband angle selective low-pass filter”.
In this work we have shown that tunable daytime passive radiative cooling is possible by using an angle-selective solar filter on top of a nocturnal radiative cooler surface. We have provided guidelines for the design of such an angle-selective solar filter, based on a one-dimensional photonic crystal composed of multiple Bragg-stacks with different periodicities designed to cover the entire solar spectrum. We have shown that the proposed device operates at its maximum performance for incidence angles equal to or larger than 23°.
The surface temperature of the radiator can be controlled from 270K to 352K in an atmosphere of 298.3K, with a maximum net cooling power of around 140 Wm-2.
This is comparable to the optimum performance of static devices. Our findings show that the proposed filter-radiator concept is promising for active control of daytime passive radiative cooling.
The full details can be found in DOI: 10.1039/C9NA00557A