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> - paint that has high emissivity in the IR window and high reflectivity in the rest of the spectrum. Does such thing exist? And, doesn't high emissivity in
by 4gotunameagain 5y ago
> - paint that has high emissivity in the IR window and high reflectivity in the rest of the spectrum.
Does such thing exist?
And, doesn't high emissivity in the IR mean high IR absorption as well ?
- the8472 5y agoIt's a fairly recent development[0], a few years before that the principle was demonstrated as a special surface coating on smooth surfaces rather than paint. And it's about the IR window[1], which is smaller than the whole IR spectrum. And sunlight delivers most of its energy in visible light and near IR, so there isn't a problem with reflecting the incoming light while radiating away into cold space in the IR window[2]. [0] https://ceramics.org/ceramic-tech-today/materials-innovations/new-reflecting-paint-achieves-full-daytime-sub-ambient-radiative-cooling https://ceramics.org/ceramic-tech-today/materials-innovation... [1] https://en.wikipedia.org/wiki/Infrared_window https://en.wikipedia.org/wiki/Infrared_window [2] https://www.researchgate.net/figure/Illustration-showing-desired-low-absorptivity-over-Solar-Spectrum-relative-to-desired_fig10_326902771 https://www.researchgate.net/figure/Illustration-showing-des...