The use of façade sun shading systems for the reduction of indoor and outdoor sound pressure levels

Abstract

External shading devices are widely used in recent buildings because they reduce the greenhouse effect due to the solar irradiation through transparent surfaces and the glare effects in interiors. The acoustic effects of these devices have not been well investigated in the literature. In this article, we use a bi-dimensional pressure acoustics finite element model of a shading device attached to a building façade, in frequency domain, to analyse the effects both in the indoor and in the outdoor environments. The finite element model was validated with experimental measurements carried out in a semi-anechoic chamber and then extended to an urban scale to evaluate the effect in the reduction of outdoor noise due to traffic. To improve the acoustic effect of the shading device, a sound absorbing material was added to the bottom side of each louvre. Results of the simulations show that external shading devices tend to increase the sound pressure level over the building façade, while the introduction of the sound absorbing material behind each louvre reduces this problem. The dependencies of the sound pressure level reduction to the geometrical factors of the shading device were investigated by means of the finite element model. The installation of louvres on a building façade can affect also the sound pressure level over a façade of a building placed 20 m away, across a road. In this article, both the effect over the façade of the opposite building and the effect over the urban area between the two buildings are analysed.

Acoustic Design Criteria in Naturally Ventilated Residential Buildings: New Research Perspectives by Applying the Indoor Soundscape Approach

“…The indoor-outdoor connection they provide has been, so far, a major limiting factor in the use of NV due to the conflict between ventilation needs and the intrusion of external noise, which impedes naturally ventilated buildings from meeting background noise limits set by acoustic standards, building design regulations and rating protocols. As a response, for a long time, research has been developing a number of solutions that try to guarantee ventilation without compromising façade noise insulation [19][20][21][22][23][24]. Each of them presents advantages and disadvantages, but, up to the now, none has taken hold on large scale.…”

The acoustic and daylighting effects of external façade sun shading systems

“…Acoustic performances have been evaluated as sound pressure level differences (Insertion Loss -IL) on building façades, between a reference scenario, without shading devices on the façade, and with various shading systems. In previous works, a standard shading system was compared to an acoustically optimised one, having louvres with sound-absorbing properties on the bottom side (Zuccherini et al, 2016) (Fausti et al, 2019) (Zuccherini et al, 2015. The conclusions of these studies are assumed in the present work.…”

“…The louvres' tilt angle was not considered in this work for daylight simulations because it was assumed that shading devices with horizontally oriented louvres constitute the best compromise between acoustic and daylight comfort: previous works have shown that louvres tilted towards sound sources can increase the sound pressure level on building façade, offering, on the other hand, the best shading to the building itself (Fausti et al, 2019.…”

A critical review of acoustic modeling and research on building façade

“…The ultimate objective of investigating façade acoustics is to improve the indoor and outdoor acoustic environment. Generally, noise reduction techniques in façade acoustics include using absorptive materials, 127 –134 adding control components, 135 –137 applying new designs, 134,138 –142 etc.…”