Complex acoustic design

In addition to legal obligations in Hungary, complex acoustic design and ensuring adequate acoustic quality also bring economic benefits in all relevant investments. Our requirements regarding the acoustics of a room are primarily determined by the function and use of the room, and the quality requirements can be determined by legislation, standards and technical building directives.

Acoustic design is a complex, multidisciplinary area, consisting of several sub-areas. In Hungary, the regulations related to construction activity require acoustic planning for buildings, which consists of the following areas of expertise: building acoustics, noise and vibration protection, room acoustics, mechanical acoustics and electroacoustic planning. These acoustic disciplines form an interlinked complex design, but these are sometimes made by different specialist designers. Complex acoustic planning can provide the necessary sound insulation, noise protection, speech comprehensibility, speech information or evacuation conditions for the function of the buildings and rooms.

Design tasks of noise and vibration protection

The purpose of noise and vibration protection design is to protect against harmful sound effects and vibrations. Such noises are generated by traffic, rail, air and various machinery and equipment (air technology, cooling, elevators, etc.) and are caused by vibrations, which can be adequately handled by various building structure solutions or by the damping of noise sources (e.g. noise protection wall, vibration insulation machine base, etc.). The results of noise and vibration protection activities are usually included in the following specialised documentations:

• the environmental technical specification (in particular the permit design documentation)
• the building acoustics technical description and the documentation of the building structures.

Typical design tasks are:

• Environmental noise protection: protection of buildings in the vicinity of the examined building against noise
  • determination of noise sources and emission of noise, assessment of operational and environmental noise effects
  • monitoring the noise load of buildings in the environment, taking into account the noise level values permitted by the legislation
• Protection against external environmental noise in the examined building
  • examination of the current existing noise load
  • body sound propagation test on existing structure, vibration insulation and vibration propagation numerical modelling as required
  • noise protection calculations, sizing of noise limiting structures
• Protection against vibration and structural noise
  • source analysis, emission testing for major vibration sources.

Noise and vibration protection work consists of on-site measurement (typically traffic noise and vibration measurement), computer modelling and dimensioning tasks. From the on-site measurements, in coordination with computer modelling, it is necessary to determine the noise sources and the means of protection against them, as well as the building’s own noise sources (machinery, equipment), which are charged to the environment.

Design tasks of mechanical acoustics

The field of mechanical acoustics primarily deals with noise reduction of air supply and ventilation (HVAC) equipment, which we consider as a part of noise and vibration protection work here. In addition to the separate acoustic technical specification, the mechanical acoustic workpieces are also included in the mechanical technical specification. Typical design tasks are:

• Protection against noise generated by building engineering equipment
  • determination of acoustic requirements for technical building equipment and systems
  • building acoustic dimensioning of building engineering spaces,
  • dimensioning of mechanical noise sources and noise protection solutions
• Performing noise and vibration protection calculations
  • dimensioning of mechanical noise sources and the solutions against them
  • dimensioning of flexible pads and vibration insulation as required
  • planning of wall breakthroughs.

Design tasks of building acoustics

The primary task of building acoustic dimensioning is to protect against noise effects inside and outside the building – to isolate disturbing noise effects. This includes technical building equipment, water supply equipment and pipes, but also protection against traffic and aviation noise, protection against noise inside the building, insulation of airborne sound and step sound, and protection against other sound effects in use. Building acoustic requirements can be defined by domestic legislation, domestic standards and good international building acoustic practices (international standards), based on the functions of the premises and the nature of the room connections. In the presence of an acoustic designer, the facilities are generally designed in full compliance with Hungarian standards, and in the case of a higher level of demand, in accordance with international practice or the relevant parts of the international BREEAM or LEED regulations in Hungary, taking into account the cooperation in the field. The requirements of BREEAM and LEED usually contain sufficient parameters tested to obtain the appropriate rating, credits and qualifications, but the design requirements must be defined more widely than described therein to achieve the appropriate acoustic quality. Where relevant, international standards should also be applied, because the coverage of domestic regulations is incomplete. The results of the building acoustic design are usually included in the relevant technical description, building structure and architectural documentation, or can be displayed independently.

Typical tasks are:

• Definition of requirements and development of technical solutions to meet these requirements
• Determination and dimensioning of façade and other external boundary structures
• Resizing of air and step sound insulation
• Dimensioning of special, individual solutions and multi-shelled structures if required
• Building acoustic dimensioning of separation structures within the building
  • building acoustic dimensioning of partitions and floor structures taking into account the maximum permissible noise level requirement of the premises,
  • determination and dimensioning of layers of building structures
  • defining the types and technical parameters of doors and windows
  • scaling for rain sound
• Performing calculations according to the relevant standards for all room connections in both vertical and horizontal directions

Tasks of room acoustic design

The purpose of room acoustic design is to ensure the appropriate acoustic quality in rooms with boundary walls (fully enclosed or partially enclosed), primarily by sizing sound reflections and sound absorption, that is, by influencing conditions other than external disturbing noise. The purpose of room acoustic design is to ensure speech intelligibility and noise reduction in various rooms (e.g. rooms for speech purposes, conference rooms, classrooms, office meeting rooms, ward rooms, commercial units, sports rooms), and in the case of multifunctional and musical rooms, to provide musical clarity, sound, sense of space and loudness for the desired musical tasks and purposes. The requirements are defined in accordance with domestic legislation and standards, international standards and the best international practices, including taking into account BREEAM, LEED and WELL requirements. The results of the room acoustic design are usually included in the relevant separate technical description and the interior design documentation, but the structural and architectural disciplines may also be affected. Typical design tasks are:

• Detailed room acoustic requirements according to the rooms’ function
• In rooms with room acoustic requirements, making proposals for applicable coverings, sizing according to accepted coverings: determining the type and quantity of coverings to be used, sizing suspended ceilings and wall coverings
• Numerical modeling-based calculations for the design of rooms with higher room acoustic demands, preparation of individual product designs

After the design program is established, the room acoustic requirements are determined according to the room function. All rooms are also examined and classified in terms of room acoustics. By classifying the rooms according to their intended use, we develop a technical solution that meets the requirements with individual or type solutions, taking into account construction cost-effectiveness considerations. Adequate room acoustic quality can generally be ensured in an impeccable quality if 0.5-1.5% investment cost is specifically separated. In the case of speech-oriented and particularly important rooms, we act with the most modern planning system, planning procedure and thoroughness in international practice. 3D acoustic modeling of the rooms are carried out by beam and beam tracking method, and if necessary with tests supplemented by finite differentiation method on small frequencies. Individually designed coverings are dimensioned using analytical and numerical models or measured after test production. Proof of technical performance and the corresponding conformity assessment are given for each highlighted room by examining several acoustic parameters as required in a location-dependent manner. The room acoustic design is implemented in accordance with the electroacoustic design, and the acoustic designer provides the special data supply tasks between the design systems.

Tasks of electroacoustic design in architectural design

The task of electroacoustic design in architectural design is the sizing of information systems for speech and music purposes. Electroacoustic design is mostly carried out as a sub-task of low-current design, in the framework of the design of audiovisual systems and complex digital infrastructure of the facility. In addition to emergency speech information systems (’emergency voice’), standard minimum requirements (MSZ 2082) apply for the design of conventional electroacoustic speech information systems. Electroacoustic design is typically implemented in collaboration with works in the fields of architecture, interior design, engineering, electricity, low voltage, room acoustics, accessibility and sports technology. Usual design content:

• Functional technical specification
• Cost estimation by system, itemized priced and unpriced asset list
• Connection diagrams, asset placement floor plans (without route plans).