Infrared Spectral Emissivity Dynamics of Surfaces Under Water Condensation - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue Advanced Functional Materials Année : 2024

Infrared Spectral Emissivity Dynamics of Surfaces Under Water Condensation

Résumé

Abstract Water condensation on a surface strongly affects its effective emissivity, especially in the atmospheric window, a wavelength range essential for outdoor applications related to energetically passive cooling and heating. The evolution of emissivity of a silicon surface during dropwise and filmwise water deposition is studied. The evolution of the spectral radiative properties shows that the increase in effective emissivity due to the growth of a droplet pattern is steeper than for a growing water film of equivalent thickness. The change of surface emissivity takes place in the first moments of condensation where droplets as small as 10 µm drastically impact the reflectance of the pristine surface. The upper limit of effective emissivity is reached for a droplet radius or film thickness of 50 µm. During dropwise condensation, effective emissivity is weighted by the drop surface coverage and then remains within an asymptotic maximum value of 0.8, while in case of filmwise condensation, it is shown to reach 0.9 corresponding to water emissivity. Micrometer‐scale spatially‐resolved infrared spectral images enable to correlate the spatial variation of spectral properties to the droplet size and localization. Such findings are of interest to the implementation of moisture‐controlled emissivity tuning and radiative sky‐coolers for dew harvesting.
Fichier principal
Vignette du fichier
Adv Funct Materials - 2024 - Lavielle - Infrared Spectral Emissivity Dynamics of Surfaces Under Water Condensation.pdf (5.38 Mo) Télécharger le fichier
Origine Publication financée par une institution
Licence

Dates et versions

hal-04585167 , version 1 (23-05-2024)

Licence

Identifiants

Citer

Nicolas Lavielle, Ahmed M Othman, Armande Hervé, Georges Hamaoui, Jipeng Fei, et al.. Infrared Spectral Emissivity Dynamics of Surfaces Under Water Condensation. Advanced Functional Materials, 2024, ⟨10.1002/adfm.202403316⟩. ⟨hal-04585167⟩
0 Consultations
0 Téléchargements

Altmetric

Partager

Gmail Mastodon Facebook X LinkedIn More