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In this paper, different sort of façades have been analyzed considering their thermal behavior along a 24 hours period. A numerical model has been developed and compared with experimental measurements considering two different façades for buildings: on the one side an opaque multilayer façade; and on the other side, a ventilated façade. The numerical model representing the temperature in every layer of the façades has been successfully validated. This model has been used for determining the thermal behavior of two new ventilated façades in which the thermal mass has been changed, observing then than the existence of the moving in the air gap affects particularly the air temperature and the thermal transmittance of the façade when the sun is incising over the façade, leading to a decrease of transmittance close to 30% along the air chamber. This quantification is fundamental in warm climates, where this effect is determinant for decreasing the cooling necessities of buildings in summer with no need of increasing the mass of the façade.

IOP PublishingRubio Michavila, C.; Candelas Valiente, P.; Belmar Ibáñez, F.; Gómez Lozano, V.; Uris Martínez, A. (2015). ABSTRACTReduction of noise in the transmission path is a very important environmental problem. The most usual method to reduce this noise level is the use of acoustic barriers. In this paper, an acoustic metamaterial based on sound transmission through subwavelength slits, is tailored to be used as an acoustic barrier is shown. This system consists of two rows of periodic repetition of vertical rigid pickets separated by a slit of subwavelength width, embedded in air. Here, both the experimental and the numerical analyses are presented. These analyses have facilitated the identification of the parameters that affect the insertion loss performance. The results demonstrated that the proposed barrier can be tuned to mitigate a band noise in mechanical plant for buildings where openings for air flow are required as well as industrial noise, without excessive barrier thickness.2

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ElsevierGómez Lozano, V.; Uris Martínez, A.; Candelas Valiente, P.; Belmar Ibáñez, F. (2013). Acoustic transmission through perforated plates with fractal subwavelength apertures. Solid State Communications. 165:11-14. ABSTRACTThe acoustic transmission response of plates perforated with fractal subwavelength holes array is studied. The Sierpinski Carpet pattern is used as fractal geometry.Ultrasound transmission spectra show that each iterative Sierpinski Carpet has the characteristic peaks and dips of the lattice constant of each array that formed the pattern.The angular dependency of the transmission coefficients shows a complex interplay between Fabry-Perot resonances, Wood anomaly minima and Lamb modes.