Managing Measurement Uncertainty in Building Acoustics

In general, uncertainties should preferably be determined following the principles laid down in ISO/IEC Guide 98-3, the Guide to the expression of uncertainty in measurement (GUM:1995). According to current knowledge, it seems impossible to formulate these models for the different quantities in building acoustics. Therefore, the concepts of repeatability and reproducibility are necessary to determine the uncertainty of building acoustics measurements. This study shows the uncertainty of field measurements of a lightweight wall, a heavyweight floor, a façade with a single glazing window and a façade with double glazing window that were analyzed by a Round Robin Test (RRT), conducted in a full-scale experimental building at ITC-CNR (Construction Technologies Institute of the National Research Council of Italy). The single number quantities and their uncertainties were evaluated in both narrow and enlarged range and it was shown that including or excluding the low frequencies leads to very significant differences, except in the case of the sound insulation of façades with single glazing window. The results obtained in these RRTs were compared with other results from literature, which confirm the increase of the uncertainty of single number quantities due to the low frequencies extension. Having stated the measurement uncertainty for a single measurement, in building acoustics, it is also very important to deal with sampling for the purposes of classification of buildings or building units. Therefore, this study also shows an application of the sampling included in the Italian Standard on the acoustic classification of building units on a serial type building consisting of 47 building units. It was found that the greatest variability is observed in the façade and it depends on both the great variability of window’s typologies and on workmanship. Finally, it is suggested how to manage the uncertainty in building acoustics, both for one single measurement and a campaign of measurements to determine the acoustic classification of buildings or building units

Integrated acoustic and thermohygrometric performances of building walls, for more efficient refurbishment strategies: first evaluations

In the recent years, the improvement of buildings energy performance has received more and more attention. The acoustic aspects are still considered often in a separate context, even if the acoustic and thermal insulation strategies applied to building structures could lead to bet-ter results if considered jointly, as both are based on the correct combination of materials, building construction techniques and workmanship. The paper’s objective is to highlight the advantages of the use of combined evaluation of thermal, hygrometric and acoustic behavior of existing building walls. The study highlights some aspects of the refurbishment actions, aiming to a more efficient integrated design of the acoustic and thermo-hygrometric perfor-mance. The analysis of the acoustic and thermo-hygrometric properties of some typical wall samples is developed on the one hand by means of acoustic measurements and, on the other hand, from walls thermo-hygrometric databases. The comparison with reference values for the acoustic/thermal performances of new and refurbished buildings allows to define the most ef-ficient integrated improvement actions. Some examples are considered and the calculation re-sults are compared to show how the acoustic performance improvement does not give neces-sarily optimal results in the thermo-hygrometric perspective and vice versa. Therefore, the need to consider both aspects at the same time is a priority

Development of an Indoor Environmental Quality Assessment Tool for the Rating of Offices in Real Working Conditions

The Indoor Environmental Quality (IEQ) refers to the quality of indoor spaces in relation to the health and well-being of users. IEQ is a holistic concept considering various components of the overall indoor comfort: thermo-hygrometric, lighting, air quality and acoustics. Each component is described through specific performance indicators and benchmarks. The quality of the built environment is assessed at different stages from design to operational phase. The scientific literature reports several case studies related to the assessment of the individual components of the IEQ Tools aimed at the evaluation of the overall IEQ. The paper proposes an assessment tool based on the SB Method (Sustainable Building Method) and the Multi Criteria Analysis for the evaluation of IEQ during the operational phase of a building. Each component of IEQ is analysed through objective indicators and calculation methods. The tool provides two main outcomes: a global score expressing the overall performance of the building from the IEQ perspective; quantitative evaluations of all indoor comfort components through monitoring and measurement of the environmental variables. The above contributes to select intervention areas to optimize indoor design and to identify technologies aimed at ensuring the best IEQ levels for users at the operational stage. The system was applied to an open-plan working space of an office building. Monitoring activities and measurements are carried out to detect the indoor and outdoor variables affecting the IEQ. All aspects of IEQ were analysed and quantified so to evaluate the overall performance of the building and provide data to improve the working conditions

Campo sperimentale comune europeo sul rumore di origine aeroportuale

none4N. Lanese; G. Moschioni; F. Scamoni; F. ValentiniN., Lanese; Moschioni, Giovanni; F., Scamoni; F., Valentin

Sperimentazione su materiali di rivestimento innovativi, aventi elevate caratteristiche acustiche, da utilizzare per il risanamento di edifici

La sperimentazione ha avuto come scopo l'individuazione di un materiale innovativo per rivestimento di pareti, con elevate caratteristiche acustiche e termiche, da utilizzare in aree urbane densamente abitate e caratterizzate da forte inquinamento acustico. Sono stati selezionati tre materiali, i quali sono stati sottoposti a prove di isolamento e assorbimento acustico

The Italian classification scheme of buildings - Application to apartments and schools

The Italian acoustic classification of buildings is described by two standards, now under revision. The UNI 11367 gives a detailed description of the classification scheme, including sampling procedures and calculation of uncertainty and is useful for buildings with a large number of homogenous elements. The UNI 11444 involves the selection of the “worst case” in a sample of measurable building elements in order to identify the building units to be completely measured. Both standards are based on voluntary application, except for the specific case of public buildings, for which there are some enforced requirements. In fact, in the case of new construction, renovation and maintenance of public buildings, environmental criteria must be pursued (CAM Decree 2017), including building acoustics (class II and other requirements of UNI 11367) and indoor acoustic comfort criteria (UNI 11532). For the latter, the standard gives limit values for the descriptors, although, for the moment, only the limit values for schools are published. This paper describes the classification procedures and reports case studies of apartments and schools in Italy where the procedure and the limit values are applied