Acoustic design tools for estimation of sound insulation performance of wood wall and floor assemblies
Time: 5:00 pm
Author: Cheng Qian
Abstract ID: 1384
The National Building Code of Canada 2015 stipulates the minimum requirements of the airborne sound insulation transmission through common interior walls and ceiling/floor assemblies. The required minimum Apparent Sound Transmission Class (ASTC) is 47 in Canada, whereas the Impact Insulation Class (IIC) for floors is recommended to be higher than 55. For many years, significant efforts were made to develop sound insulation prediction models or tools to predict the sound insulation performance of wall and floor/ceiling assemblies at the design phase in order to meet the requirements and the recommendations made by codes. However, today few models can provide a reliable acoustics design tool. In this document, three prediction tools thought to be practically useful are presented and evaluated. Between these three prediction tools, one is an analytical model of the Insul software while the other two are empirical models developed by the National Research Council of Canada and the American Wood Council. This paper compared the STC and IIC ratings of wood wall and floor assemblies estimated by these three models and verified them by the measured STC and IIC ratings. This work aims at providing an idea for readers to choose a suitable design tool to proceed with their acoustic designs.
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Analytical model of the diffuse sound transmission loss of finite double panel structures
Time: 4:40 pm
Author: Javier Vazquez Torre
Abstract ID: 1908
An analytical model for the forced sound transmission loss of finite single-leaf walls using a variational technique was previously developed and validated. As the double panel is one of the most used structures in building acoustics, the aim of this paper is to extend the analytical model to consider double panel structures. Analytical formulas for the forced part of the airborne sound insulation of finite sized double panel structures are derived using a variational technique based on the integral-differential equation of the fluid loaded panels. The formulas are valid in the entire audible frequency range. The results are compared to alternative analytical models and measurements, with reasonable agreement.
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Room acoustics criteria and measurements of lobbies and atria for various building types
Time: 1:20 pm
Author: Ted Pyper
Abstract ID: 2132
The lobby or atrium for a building may serve many purposes -- entryway, welcome area, circulation zone, and architectural point of interest. Increasingly, lobbies and atria serve more and more functions: gathering area, presentation area, music and event space, study area, and dining, among other uses. Since variable acoustics in lobby spaces are not typically feasible or desirable, the acoustical design of lobby spaces must strike a balance for the variety of events planned for the space. Working with design teams and owners to understand the needs of each space, acoustical design criteria evolve based on project-specific needs and previous experience. In this presentation, lobbies are considered for various building types, including education facilities, student commons, museums, and performing arts buildings. In addition to studies of existing spaces and modeling of buildings in design, this presentation expands on the authors' previous efforts by documenting the measured reverberation and background noise in several lobbies and atria after the completion of design and construction.
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Acoustic decoupling for structural elements by affixed supports – inherent contradiction or perfect complement? Restrained vibration isolation supports – a critical review
Time: 5:00 pm
Author: Adam Wells
Abstract ID: 2234
Restrained vibration isolation supports balance efficient isolation performance and stability for the supporting body under present loads. Necessary and beneficially for noise and vibration isolation applications with stringent stability requirements, such as full building isolation with potential uplift, interior partition sway bracing, curtain walls, elevator rail isolation, and mechanical vibration isolation, the performance of restrained vibration isolators are often misunderstood or oversimplified. This paper investigates the general vibration isolation theory used to create the analytical model for restrained isolation supports, intricacies of vibration isolation materials which may cause reality to diverge from well-known models, comparison of theory to laboratory testing, and a review of common uses/applications for these types of vibration isolation solutions, and recommendation to avoid undesired results from common pitfalls associated with restrained isolation supports implementation and installations.
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A review of uncertainty in sound isolation testing
Time: 2:40 pm
Author: Jameson Dickman
Abstract ID: 2322
Construction industry design standards are increasingly calling for new construction to be inspected and tested for compliance with design specifications after the project is built; otherwise known as the commissioning process. As part of this trend, owners, sensitive to the acoustics of their facilities, are seeking confirmation via measurements that their buildings meet sound isolation and background noise requirements, particularly when pursuing certifications under the US Green Building Council LEED standard, the WELL Building Standard, or other green building or wellness standards. In general, the error of sound isolation measurements is not officially established. This poses challenges to designers tasked with specifying assemblies and components to meet field verification requirements. This paper will briefly review current research and standards on the error of measurements such as Noise Isolation Class (NIC) and the Weighted Level Difference (D) and discuss example design standards and guidelines which do or do not account for this error. It will also propose further research topics to better define the error in sound isolation measurements and best practices when establishing or designing to sound isolation criteria in new or renovated buildings.
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Soundproof Window – Natural Ventilation
Time: 3:00 pm
Author: Vinícius Ávila Ferreira
Abstract ID: 2361
Expansion of brasilians cities worsen noise pollution in these places, forcing people to maintain their doors and windows closed. Domestic environment enclosing lead to necessity of air conditioning system, however the frequent use of the equipment may cause many health problems, such as respiratory difficulties and spread of diseases , not to mention high costs with energy. Considering these facts, there is the need of soundproofing windows with air supply , that allows passage of air without noise passage, guarantee a well-ventilated environment, with thermic and acoustic comfort without the use of acclimatisation systems . we have developed two prototypes with significant opening that allows air supply (passage) (0,35m2) and noise reduction (Rw+Ctr) reaching 8 to 10 dB. In the first study, we considered people inhabiting really noisy surrounding areas, who has already installed a regular window. In this particular case, we developed a soundproofing window air supply that can be installed over the existing one. A second study considered new constructions to focus the environment where the person sleeps and then elaborate a soundproofing window air supply for bedrooms. Keywors: soundproofing windows, air supply, sound insulation. noise pollution
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The impact of the cracks in the window
Time: 4:20 pm
Author: Vinícius Ávila Ferreira
Abstract ID: 2583
When we talk about the acoustic insulation performance of a building facade, we know that its weakest link is the frame that makes it up. We soon know that great performance on the part of this component is necessary so that the facade assembly can obtain high levels of insulation. Although there are several lines and models of frames, each with two unique characteristics and varied acoustic performance, they have a similarity in their result curve. where at high frequencies it becomes a decisive point for your result. In this work, we will analyze the vulnerable points of a typology of mitering, focusing on its cracks and the impact that each one has on its result; as well as measures that can be taken so that the frame can acquire great acoustic performance, without changing the profile lines or glass thickness.
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Impact of lamination on acoustic performance
Time: 4:40 pm
Author: Vinícius Ávila Ferreira
Abstract ID: 2585
When we speak of laminated glass, it has several variations of lamination. either increasing the number of laminations between glasses or the thickness of the lamination. But how much does this really impact your acoustic performance? In this work we will analyze different types of lamination and understand the difference in the performance curve of each one and how much this impacts on its result, whether global or at a certain frequency.
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A Sound Insulation Prediction Model for Floor Structures in Wooden Buildings Using Neural Networks approach
Time: 5:20 pm
Author: Mohamad BADER EDDIN
Abstract ID: 2619
Recently, machine learning and its applications have gained a large attraction in different fields. Accurate predictions in building acoustics is vital especially in the design stage. This paper presents a sound insulation prediction model based on Artificial Neural Networks (ANNs) to estimate acoustic performance for airborne and impact sound insulation of floor structures. At an initial stage, the prediction model was developed and tested for a small amount of data, specifically 67 measurement curves in one third octave bands. The results indicate that the model can predict the weighted airborne sound insulation for various floors with an error around 1 dB, while the accuracy decreases for the impact sound especially for complex floor configurations due to large error deviations in high frequency bands between the real and estimated values. The model also shows a very good accuracy in predicting the airborne and impact sound insulation curves in the low frequencies, which are of higher interest usually in building acoustics. Keywords: building acoustics, airborne sound, impact sound, prediction model, neural networks
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The effects of acoustical ceiling panel type and penetrations for services on vertical sound isolation inside buildings
Time: 6:00 pm
Author: Gary Madaras
Abstract ID: 2639
Attenuation of sound transmitting between rooms oriented over one another inside buildings is studied. Transmission loss and sound transmission class were measured by an independent, accredited, acoustics laboratory with and without a variety of modular acoustic ceilings suspended under a baseline concrete floor structure. Ceiling panel material types include stone wool, fiberglass and mineral fiber. Ceilings were tested with and without the presence of service penetrations for supply air diffusers, return air grilles and light fixtures. Some ceilings were also scanned with a sound intensity probe and the resulting color sound maps are used as a supplemental method of evaluating both isolation and absorption performance of the individual components of the ceiling systems. Results show that while the effects of ceiling panel type on absorption performance, and thus room acoustics, is substantial, the material type and weight of the ceiling panels do not substantially affect the overall isolation performance of the floor-ceiling assembly.
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An overview of room acoustics requirements in North American, nonresidential, building standards
Time: 12:20 pm
Author: Gary Madaras
Abstract ID: 2943
In the United States and elsewhere in North America, acoustics requirements for nonresidential buildings in Federal acts, codes, official standards and unofficial guidelines and rating systems tend to be voluntary, grass-roots and bottom-up instead of being mandatory, top-down or governmentally mandated. This relates to the governmental viewpoint that noise is merely a nuisance, not a health risk as viewed in other parts of the world. Existing requirements associated with noise control whether they are related to environmental/community noise, transmission of transportation noise through the building envelope or occupant noise through the interior construction assemblies or minimizing noise from building services are more prevalent in these standards. Requirements for good room acoustics related to sound absorption, speech intelligibility and distraction-free and comfortable interiors that promote human health and well-being are appearing in more standards and being updated to have more stringent values. Much improvement is still needed in older standards that do not have regular revision cycles and open, public, review periods. An overview of the types of room acoustics metrics used, their evolving values, advantages/disadvantages and the research behind them will be provided. Recommendations for future advancements will be offered.
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Brazilian BIM Objects Technical Standard: a first approach on Acoustics parameters
Time: 7:40 pm
Author: Paola Weitbrecht
Abstract ID: 3054
The Building Information Modeling (BIM) has increased worldwide as a new approach on the building design, construction, and facilities management. Given this panorama, the Brazilian Government enforced a regulation in 2019, Decreto 9983, which outlines a roadmap for the BIM implementation in the Brazilian construction ecosystem. As one of its guidelines is to publish the necessary technical standards, a special committee, ABNT CEE 134, was hosted at the Brazilian organization for Technical Standardization with a dedicated WG for establishing BIM objects parameters. In the framework of the WG, a subgroup on Acoustics analysis aimed to deal on how to incorporate acoustic requirements to the BIM Object. In this paper, the authors describe the development of this feature, unprecedented so far. The approach adopted for incorporating acoustic requirements into BIM objects at the Brazilian BIM Standard aimed to facilitate the workflow of acoustic consulting, while adapting it to the limitations imposed by the existing software and the construction market culture in Brazil. This paper also provides some guidelines on how this issue could be addressed in future standards revisions.
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Subjective and objective evaluation of the impact and airborne sound insulation of multi-unit residential buildings
Time: 5:40 pm
Author: Maedot Andargie
Abstract ID: 1648
Multi-unit residential building (MURB) occupants often express dissatisfaction with their suites' acoustic conditions despite existing building acoustic standards and regulations as well as growing research on noise control and building acoustics. Reasons for this include the lack of proper characterization of acoustic comfort in MURBs and lack of comprehensive and stringent regulations. To better understand factors that impact acoustic comfort and explore strategies to improve the acoustic performance of MURBs, investigations of acoustic conditions were carried out. This work presents the results of the investigations which include subjective and objective evaluations of acoustic conditions in two MURBs. Impact sound insulation measurements using both a tapping machine and a rubber ball as well as 24-hour indoor noise monitoring were carried out in unoccupied suites. An online survey was then used to collect subjective assessments of the noise conditions in the buildings and the effects on occupants comfort post occupancy. Results of the data analysis suggest that occupants are more sensitive to low-frequency impact sounds than mid- and high-frequency impact noise.
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