The sky is a natural heat sink that has been extensively used for passive radiative cooling of households. A lot of focus has been on maximizing the radiative cooling power of roof coating in the hot daytime using static, cooling-optimized material properties. However, the resultant overcooling in cold night or winter times exacerbates the heating cost, especially in climates where heating dominates energy consumption. In this work, we approached thermal regulation from an all-season perspective by developing a mechanically flexible coating that adapts its thermal emittance to different ambient temperatures. The fabricated temperature-adaptive radiative coating (TARC) optimally absorbs the solar energy and automatically switches thermal emittance from 0.20 for ambient temperatures lower than 15°C to 0.90 for temperatures above 30°C, driven by a photonically amplified metal-insulator transition. Simulations show that this system outperforms existing roof coatings for energy saving in most climates, especially those with substantial seasonal variations.
@article{osti_1875448,
author = {Tang, Kechao and Dong, Kaichen and Li, Jiachen and Gordon, Madeleine P. and Reichertz, Finnegan G. and Kim, Hyungjin and Rho, Yoonsoo and Wang, Qingjun and Lin, Chang-Yu and Grigoropoulos, Costas P. and others},
title = {Temperature-adaptive radiative coating for all-season household thermal regulation},
annote = {The sky is a natural heat sink that has been extensively used for passive radiative cooling of households. A lot of focus has been on maximizing the radiative cooling power of roof coating in the hot daytime using static, cooling-optimized material properties. However, the resultant overcooling in cold night or winter times exacerbates the heating cost, especially in climates where heating dominates energy consumption. In this work, we approached thermal regulation from an all-season perspective by developing a mechanically flexible coating that adapts its thermal emittance to different ambient temperatures. The fabricated temperature-adaptive radiative coating (TARC) optimally absorbs the solar energy and automatically switches thermal emittance from 0.20 for ambient temperatures lower than 15°C to 0.90 for temperatures above 30°C, driven by a photonically amplified metal-insulator transition. Simulations show that this system outperforms existing roof coatings for energy saving in most climates, especially those with substantial seasonal variations.},
doi = {10.1126/science.abf7136},
url = {https://www.osti.gov/biblio/1875448},
journal = {Science},
issn = {ISSN 0036-8075},
number = {6574},
volume = {374},
place = {United States},
publisher = {AAAS},
year = {2021},
month = {12}}
Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States). Molecular Foundry
Sponsoring Organization:
USDOE Office of Science (SC), Basic Energy Sciences (BES). Materials Sciences & Engineering Division; USDOE Office of Energy Efficiency and Renewable Energy (EERE), Energy Efficiency Office. Building Technologies Office; National Science Foundation (NSF)