The radiative cooling of stainless steel/tin/glass multilayer systems T

The radiative cooling of stainless steel/tin/glass multilayer systems
T. Mouhib1,2 , M. Benlattar1 , A. Mouhsen1 , M. Harmouchi1 , P. Defrance2 , J. P. Vigneron3
and E. M. Oualim1
1 Laboratoire
Optique Appliquée et Transfert Energie, Faculté des Sciences et Techniques, B.P. 461, Settat, Morocco
de Physique Atomique, Moléculaire et Optique, Université Catholique de Louvain, Chemin du Cyclotron 2,
B- 1384 Louvain La Neuve, Belgium
3 Laboratoire de Physique du Solide,Facultés Universitaires Notre-Dame de la Paix, Rue de Bruxelles, B- 5000
Namur, Belgium
2 Unité
The radiative cooling method uses the fact that the thermal energy emitted by a clear sky from 8 to 13 µ
in wavelength, known as atmospheric window, is much less than the thermal energy emitted by a blackbody
at ground air temperature in this wavelength range. It could be envisaged in different applications including
cold storage and climatization of buildings [1]. In the last decades, many experimental and theoretical
studies of multilayer materials have been devoted to identify the materials, which can carry out the radiative
cooling effect [2,3]. The key is to choose the materials, which show the appropriate spectral selectivity. The
present work concerns the production of stainless steel/tin/glass (SSTG) multilayer systems and the study
of their optical properties to assess the possibility of this system for radiative cooling usage. The stainless
steel (45 nm)/tin(195nm)/glass(3mm) systems have been prepared by sputtering. The optical properties
have been measured by a spectroradiometer OL750. The results shown in figure 1 exhibit the expected
optical properties.
To test for the radiative cooling effect, a blackbody was covered by a cubic enclosure of 0.3x0.3x0.3
m of SSTG multilayer. The temperature of the blackbody exposed to the sun was measured by four
soundings TMC 50-HA connected to an automatic recorder (HOBO H8 4-Channel External). The results
(figure 2) clearly show the radiative cooling effect, a difference larger than 22◦ C being observed around the
maximum.
3
[1] C. G. Granqvist, T. S. Eriksson, in: C. G. Granqvist (Ed.), Materials for Solar Conversion Systems,
Pergamon Press, 1991.
[2] E. M. Oualim and M. Harmouchi, Phys. Chem. News 6 (2002) 23-27.
[3] K. D. Dobson, G. Hodes, Y. Mastai, Sol. Energy Mater. Sol. Cells 80 (2003) 283-296