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Sound absorption by openings has been rarely considered in room acoustics. In fact, information about small openings (such as ventilation grids) may sometimes be found, but nothing is said about larger openings, possibly as a consequence of the less likely occurrence in a design. In order to fill this gap, measurements were carried out in scale models, measuring the equivalent absorption due to different openings and comparing it with theoretical results. A 'practical' model, showing a simple dependence on the opening dimension, was finally obtained and subsequently validated by measurements in a real room. [ABSTRACT FROM AUTHOR]

The purpose of this study is to provide a snapshot of the agro-waste production in Puglia, Molise, Albania and Montenegro, some of the regions belonging to EUSAIR (ADRIATIC-IONIAN REGIONS) correlating this aspect to the possible use of agro-waste in the building sector. EUSAIR is a functional area, facing the Adriatic sea, treating the marine, coastal and terrestrial areas as interconnected systems. In the first part of the paper, the state of the art about the current consumption of agricultural biomass is carried out referring to the ongoing research lines. It was shown that a great number of international studies have demonstrated that the agro-waste plays an important role in several fields. Moreover, several researchers conducted studies on hygrothermal, physical and acoustical properties of building materials made with biomass proving the potentiality to use this kind of by-product. Then, the state of the art regarding the production and current way of disposal of the agro-waste in the regions of the EUSAIR above mentioned was performed in order to outline the possible by-products which are suitable to be re-used in the building sector. The correlation existing between the agro-waste and the possible use in the building sector is finally presented, focusing on the legislative framework currently existing in each of the regions. [ABSTRACT FROM AUTHOR]

The paper describes the results of research aimed at investigating the preferred subjective listening conditions inside churches. The effect of different musical motifs (spanning Gregorian chants to symphonic music) was investigated and regression analysis was performed in order to point out the relationship between subjective ratings and acoustical parameters. In order to present realistic listening conditions to the subjects a small subset of nine churches was selected among a larger set of acoustic data collected in several Italian churches during a widespread on-site survey. The subset represented different architectural styles and shapes, and was characterized by average listening conditions. For each church a single source–receiver combination with fixed relative positions was chosen. Measured binaural impulse responses were cross-talk cancelled and then convolved with five anechoic motifs. Paired comparisons were finally performed, asking a trained panel of subjects their preference. Factor analysis pointed out a substantially common underlying pattern characterizing subjective responses. The results show that preferred listening conditions vary as a function of the musical motif, depending on early decay time for choral music and on a combination of initial time delay and lateral energy for instrumental music. [Copyright &y& Elsevier]

Among environmental factors, noise represents one of the most relevant determinants on human health and on the urban quality level and, consequently, on real estate values. Thus, the noise pollution issue plays a significant role in public urban policies aimed at increasing the acoustic comfort level and creating more sustainable and comfortable cities. The real estate market is highly sensitive to noise factor and the residential prices can be strongly influenced by a high acoustic pollution rate. The present research aims to analyze the functional relationships between noise pollution and selling prices in four municipal areas of the city of Bari (Southern Italy). For each area, a study sample constituted by two hundred residential properties sold in 2017–2019 was detected for the identification of the main influential factors on prices and the investigation of the contribution of noise on them. The implementation of an econometric technique was used to obtain four different models (one for each municipal area of the city of Bari) able to explain the specific impact of noise pollution level on selling prices. From the comparison of the results obtained for each area, the outputs confirm the expected phenomena in terms of a decrease of noise component influence on residential prices from the central area to the peripheral. For the suburban area of the city of Bari, the model obtained does not include the noise pollution factor, showing a lower (scarce) importance of the environmental factor among the buyer and seller bargaining phases. [ABSTRACT FROM AUTHOR]

Deep Reinforcement Learning (DRL) proved to be successful for solving complex control problems and has become a hot topic in the field of energy systems control, but for the particular case of thermal energy storage (TES) systems, only a few studies have been reported, all of them with a complexity degree of the TES system far below the one of this study. In this paper, we step forward through a DRL architecture able to deal with the complexity of an innovative hybrid energy storage system, devising appropriate high-level control operations (or policies) over its subsystems that result optimal from an energy or monetary point of view. The results show that a DRL policy in the system control can reduce the system operating costs by more than 50%, as compared to a rule-based control (RBC) policy, for cooling supply to a reference residential building in Mediterranean climate during a period of 18 days. Moreover, a robustness analysis was carried out, which showed that, even for large errors in the parameters of the system simulation models corresponding to an error multiplying factors up to 2, the average cost obtained with the original model deviates from the optimum value by less than 3%, demonstrating the robustness of the solution over a wide range of model errors. [ABSTRACT FROM AUTHOR]

A significant dependence of sound absorption as a function of incidence angle was found, and as a function of the period absorber layout, which made sound absorption decrease when the period was comparable with the wavelength. Sound absorption coefficients, flow resistivity, and other physical properties were determined and the results showed relatively little influence of the binder on the acoustic behavior. [Extracted from the article]

The changing climate has introduced new and unique challenges and threats to humans and their environment. Urban dwellers in particular have suffered from increased levels of heat stress, and the situation is predicted to continue to worsen in the future. Attention toward urban climate change adaptation has increased more than ever before, but previous studies have focused on indoor and outdoor temperature patterns separately. The objective of this research is to assess the indoor and outdoor temperature patterns of different urban settlements. Remote sensing data, together with air temperature data collected with temperature data loggers, were used to analyze land surface temperature (outdoor temperature) and air temperature (indoor temperature). A hot and cold spot analysis was performed to identify the statistically significant clusters of high and low temperature data. The results showed a distinct temperature pattern across different residential units. Districts with dense urban settlements show a warmer outdoor temperature than do more sparsely developed districts. Dense urban settlements show cooler indoor temperatures during the day and night, while newly built districts show cooler outdoor temperatures during the warm season. Understanding indoor and outdoor temperature patterns simultaneously could help to better identify districts that are vulnerable to heat stress in each city. Recognizing vulnerable districts could minimize the impact of heat stress on inhabitants. [ABSTRACT FROM AUTHOR]

The internationally recognized procedure ISO 354:2003 for measuring sound absorption coefficients under diffuse field conditions is now under revision. The main reason for this revision is the limited reproducibility of absorption coefficients measured in different laboratories that may have significant implications spanning from room acoustic design to material selection. A network of Italian laboratories have come together to carry out an Inter-Laboratory Test (ILT) to assess and compare the measurement uncertainties resulting from the application of the current version of ISO 354:2003 and of the new ISO/CD 354:2019. After detailing the methodological aspects, the paper presents the results of the measurements, discussing the compliance of the laboratories to the standard requirements and new qualification tests, and, more importantly, providing a quantitative estimation of their effects on measurement uncertainty and accuracy. [ABSTRACT FROM AUTHOR]

Abstract The paper presents the results of an experimental activity aimed at producing and characterizing a nano-encapsulated PEG600 (PCMs) into a silica shell. The nano-encapsulation was meant to be useful to improve the material's suitability to integration in building components. The (300±15)nm nanoparticles that were produced underwent a full characterization of their thermal performances. An enthalpy of fusion as high as 66.24 kJ/kg, in a tight melting temperature range (20–21°C) was obtained, making the material suitable for thermal energy storage in buildings. In order to demonstrate the benefits of such as this technology on the reduction of heating and cooling demand of buildings, a concentration of 50% in weight of nanoparticles was, then, embedded into a gypsum plasterboard and used for all indoor plastered surfaces of a reference residential buildings. A saving of respectively up to 4.3% and up to 1.1% of heating and cooling energy demand was predicted in comparison to the ones of a building without PCM. Finally, the material underwent a full toxicological characterization exposing human alveolar basal epithelial cells to nanoparticles. The results showed that there were no toxic effects on cell morphology. [ABSTRACT FROM AUTHOR]

This study assesses the influence of photovoltachromic windows (PVCCs) on the Life Cycle Impact and Life Cycle Total Energy of office buildings. To this aim, two commercial buildings, having the same size and typology, only differing on glazing's technologies—PVCCs and commercial solar control glass panes integrated with photovoltaic (PV) panels—were compared. A full analysis was performed in three locations representative of as many climatic conditions (Aswan, Brindisi and London). The results obtained showed that the overall impact due to the production of a PVCC cell is considerably lower than the one of traditional technologies offering the same performances. Reductions of impacts spanning between 41% and 44% were obtained. Moreover, all impact categories benefited from smart windows' building integration in the operational phase, especially in the Mediterranean climate. If in Aswan the reduction of impact is mainly ascribable to energy demand for cooling, in cold climates savings in lighting energy dominate. [ABSTRACT FROM AUTHOR]

• A novel photochromic (PC) film was developed and tested for smart windows. • Building integration in a standard medium office building was modelled. • Energy saving were assessed, comparing PC glazing with standard compliant glazing. • Up to 4 MWh/year of energy saving and 40% of visual comfort increase were reached. • The dynamic behaviour of the PC film is the best choice for visual comfort. The study of chromogenic materials and systems is particularly promising for innovative, transparent building envelopes, with thermo-optical properties adaptable to surrounding environmental conditions. This work spots light on the multiple effects of photochromic glazing on the energy consumption of buildings and on the impact that such technologies would have on the visual comfort of occupants. To our knowledge, this is the first work dealing with building integration of spirooxazine-based photochromic films. This experimental and theoretical work aims helping to fill this gap by reporting the results of a study concerning the spirooxazine photochromic molecules, integrated in transparent matrices of polymethylmethacrylate. This work discloses the potential of specific photochromic materials, especially as a function of spectral peculiarities. The figures of merit of this technology have been studied by assuming its integration in an ideal multi-storey office building, and by studying the effects in terms of energy consumption and visual comfort and proposing a comparison with several static commercial glazing technologies. The photochromic glazing demonstrated to offer significant reduction of energy use for cooling, compared to a clear glass (with yearly saving of 4079 kWh, on the Southern facade), and for artificial lighting (with a saving of 3711 kWh), if compared to the commercial solar control glazing. Furthermore, the dynamic behaviour of the photochromic glazing represented the best choice in terms of visual comfort. [ABSTRACT FROM AUTHOR]

A tailored multifunctional diatomite-based foam with porosity and density gradients has been developed through a new technology that enables an unprecedented integration of acoustic, mechanical and thermal properties. The production process consists of a custom-made pilot plant for foaming capable of mixing solid phases, such as diatomite, catalyst and silicon chemical blowing agent, with a liquid solution, made of sodium silicate cross-linking agent and vegetable foaming agent. The resulting foam exhibits a coin-like performance, with a side A showing an open cell morphology, high interconnectivity and low density, and a side B characterized by a partially open cells morphology, low interconnectivity and high density. This approach enables morphology and density to be layered along thickness. A transition zone with intermediate density and morphology separates the two sides, thus rendering the structure a gradient meta-material with hierarchical porosity. M acro- and micro -porosity are generated by physical and chemical foaming agents, while diatomite is responsible for the presence of nanoporosity. The gradient structure has a huge influence on functional properties, such as acoustic (α equal to 0.95 at 800 Hz for side A), thermal (thermal conductivity less than 0.061 W/(m·K) for side A and less than 0.12 W/(m·K) for side B) and mechanical properties. [Display omitted] • Diatomite-based foams with porosity and density gradients were tested. • The gradient structure had a huge influence on functional properties. • Higher density layer @ 447 kg/m3 shows 2.5 MPa in YS. • Lower density layer @216 kg/m3 shows 0.16 MPa in YS and acoustic behaviour of porous materials. • Measured thermal conductivity ranged between 0.06 and 0.17 W/(m·K). [ABSTRACT FROM AUTHOR]

This study presents a prediction of the yearly energy production and visual comfort benefits deriving from the adoption of building integrated semitransparent photovoltaic windows. Measured electrical and optical properties of neutral-colored solid-state planar heterojunction perovskite cells, characterized by promising transparency and photovoltaic conversion efficiency, were applied to a hypothetic photovoltaic glazing. Such experimental data were used as input to estimate annual energy production and visual comfort effects. The effect of different climate conditions was also investigated. A south-oriented test-room was modelled, assuming two window-to-wall ratios (WWRs) for office buildings, 19% and 32%, respectively. Energy yield was calculated at different locations showing figures between 20 and 30 kWh/m 2 per year, with negligible reduction (not exceeding 3% in the hottest climates) when cell temperature was taken into account. Visual comfort assessment was carried out using two typical metrics: Useful Daylight Illuminance (UDI) and Daylight Glare Probability (DGP), comparing the performances of a photovoltaic glass with those of a commercial solar control glass and of a clear glass, acting as a reference. We found that the use of photovoltaic glass, independent of the location latitude, showed a significant increase in UDI values respect to clear glasses and performances comparable to solar control glasses. With reference to DGP, the use of photovoltaic glass allowed the reduction of occurrence of high DGP values (>0.45) of about 12–23%, depending on the location. Finally, we compared the annual energy production of building integrated photovoltaic cells to the annual use of electric energy for artificial lighting, finding that in most of the cases the annual energy production overcomes the amount of electric energy used for artificial lighting. [ABSTRACT FROM AUTHOR]

The limited availability of natural resources and the environmental impacts related to their extraction are the main reasons for developing construction materials using industrial residues as raw materials. On the other hand, the growing attention to the well-being of building occupants encourages the scientific community in proposing strategies not only sustainable, but also able to improve both the indoor acoustic and thermal comfort. The present work proposes nonwoven materials differing in density and thickness, obtained from textile waste, following an airlaying industrial process. The acoustic and thermal performances of the developed materials were investigated. Air flow resistivity was lower than 100 kN s/m4 resulting in diffuse sound absorption coefficients higher than 0.6 starting from 500 Hz for 2.5 cm thick panels. A detailed characterization of the damping properties of the prepared samples (i.e. a total dynamic stiffness ranging from 7 to 13 MN/m3 and an average loss factor ranging from 0.22 to 0.27), made it possible to model the sound insulation behaviour, proving significant improvements when the materials were applied as resilient layers in a floating floor or as insulating material in opaque façades. Furthermore, all the tested nonwovens showed a thermal conductivity lower than 0.05 W/(m·K), representing a good solution for the improvement of the energy efficiency of the building envelope. • Nonwovens made from textile waste were produced following an airlaying process. • All the samples were tested in terms of thermal, acoustic and elastic properties. • Measured thermal conductivity was lower than 0.06 W/(m·K) for all samples. • Promising normal and random sound absorption coefficients were obtained. • The nonwovens showed damping properties to be used for improving sound insulation. [ABSTRACT FROM AUTHOR]

This experimental work reports the activities of design, fabrication and characterization of an innovative solid-state electrochromic device, deposited on a single substrate with high transparency in the bleached conditions and a wide modulation of transmittance (ΔT of 60% at 750 nm) both in the visible and near-infrared wavelengths. A tailored formulation of the solid electrolytes, based on sulfonated tetrafluoroethylene-based fluoropolymer-copolymer dispersions and the accurate design of a suitable layer of porous tin oxide nanoparticles provided high coloration and bleaching kinetics and recovery of the pristine conditions, even after 500 complete cycles. Devices were scaled-up to 10 × 10 cm2 size, without mechanical and aesthetic defects and relevant homogeneity, throughout the coloration and bleaching processes. Furthermore, this device shows the further feature to be a low-emissivity dynamic solar control film, highly compatible with integration within insulated glazed units. • A simplified architecture for solid-state electrochromic devices. • High transparency (>80%) and transmittance modulation (>60%), fast kinetics. • Fair low-emissive properties (ε = 0.52) of scaled-up prototypes, after 500 cycles. [ABSTRACT FROM AUTHOR]

Reusing textile waste in building applications has the potential to reduce the environmental impact of two sectors considered the main sources of environmental pollution: the textile and the construction industries. Thus, the main goal of the present research study is to assess the potential conversion of wool waste into new raw materials suitable for building components. Hence, hygrothermal, acoustic and non-acoustic properties of nonwovens consisting of 100% wool waste fibers thermally bonded with polyester/copolyester bi-component fibers were explored. Five different density values (51, 90, 115, 136 and 167 kg/m3) were examined. Absorption coefficients ranging from 0.7 to almost 1 were measured above 1 kHz using 50 mm thick samples; thermal conductivity values from 0.044 to 0.057 W/(m·K) were obtained and a water vapour permeability close to 2·10−11 kg/(m·s·Pa) was found. Furthermore, a comparison between nonwovens under test and other previously experimented materials was carried out. Measurement results showed that the manufacturing processes mainly affected the sound absorption coefficients and the hygric properties of the fibrous nonwovens. Comparison between tested materials and those currently available on the market allows to state that the tested nonwovens may represent a valid alternative for building applications, thus opening a new research area. • Textile nonwovens made from wool waste and bi-component fibers were tested. • Measured thermal conductivity was lower than 0.06 W/(m·K) for all samples. • All materials showed sound absorption coefficients higher than 0.7 at frequencies from 500 Hz on. • The manufacturing technique mainly affected the sound absorption and the hygric properties of the fibrous nonwovens. [ABSTRACT FROM AUTHOR]

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Thermal discomfort is one of the main triggers for occupants' interactions with components of the built environment such as adjustments of thermostats and/or opening windows and strongly related to the energy use in buildings. Understanding causes for thermal (dis-)comfort is crucial for design and operation of any type of building. The assessment of human thermal perception through rating scales, for example in post-occupancy studies, has been applied for several decades; however, long-existing assumptions related to these rating scales had been questioned by several researchers. The aim of this study was to gain deeper knowledge on contextual influences on the interpretation of thermal perception scales and their verbal anchors by survey participants. A questionnaire was designed and consequently applied in 21 language versions. These surveys were conducted in 57 cities in 30 countries resulting in a dataset containing responses from 8225 participants. The database offers potential for further analysis in the areas of building design and operation, psycho-physical relationships between human perception and the built environment, and linguistic analyses.

Background: Thermal, acoustic and visual comfort conditions for hypermarket workers have never been investigated with scientific methods., Objectives: taking advantage of a case study, with characteristics capable of generalizing the results, analytically measure the actual comfort conditions to which workers are exposed and point out possible ameliorative proposals., Methods: Carry out a detailed survey based on instrumental measurements combined with subjective questionnaires to assess the indoor environment., Results: Even though the analysis pointed out no significant risk conditions, several smaller problems appeared in terms of local discomfort (such as cold limbs, higher sound level exposure, limited glare phenomena) for cashier workers. The origin of these problems appeared to be the pivotal position of the cash registers., Conclusions: Taking into account observed phenomena and their causes a list of "best practices" has been defined hoping that their adoption could further limit any impact on workers comfort conditions.