Atenuadores para controle de ruído em sistemas de ar condicionado: estudo de caso com a utilização de materiais fonoabsorventes reaproveitados

Abstract

Central air conditioning, ventilation and exhaust systems designed for multifunctional projects are effective and essential for the thermal comfort of users. However, these systems emit and propagate significant noise during their operation and require the implantation of acoustic attenuators strategically positioned along the air distribution branches in order to attenuate the radiated sound waves and provide greater acoustic comfort. Complaints arising from excessive noise perceived by people in their daily lives are commonly verified, and noise pollution is indicated as one of the causes of public health problems (WHO, 2011). However, the lack of awareness and attention to the generation of noise can be requested by those who are disturbed due to the current legislation that brings parameters and tolerances to be respected. The emerging concerns related to noise became a subject of common interest and directly linked to the preservation of the quality of daily life (PATRÍCIO, 2018). The potential noise problems of Heating, Ventilation and Air Conditioning - HVAC - systems are evidenced by professionals in the area who seek solutions for each new project. In this sense, two forms of action can be distinguished: engineers are specifying sound-absorbing and vibration-isolating equipment and materials, while architects are proposing walls and slabs consistent with noise transmission reduction parameters (SCHAFFER, 2011). In the current context, acoustic attenuation equipment follows the dimensions of the ducts that direct the fluid to desired environments and have internal cells of a standard format. However, understanding that the spatial relationship, volume and shapes impact on the attenuation capacity of the phonoabsorbent cells (EGAN, 2014), an in-depth study on the subject is necessary.