Building Simulation Applications BSA 2022

x The ready-made garment (RMG) sector is an essential contributor to the economy of Bangladesh. Most RMG buildings in the country are often found to be inefficient in terms of natural light, energy consumption and the thermal comfort of the workers. Computational modeling, simulation and optimization analysis could be used during the building planning and design phases to effectively integrate these three issues and improve the working environment. This research first evaluates both daylighting and energy performance of a real-world existing air-conditioned RMG factory building in Dhaka. Next, an optimized design solution is proposed for the factory. Finally, we correlate the relationship between design variables and performance metrics. Nine independent variables (north, south, east and west window-to-wall ratios and shading; and skylights) are identified to evaluate performance. The variables are connected with parametric sliders (value expressed by a range of numbers despite a constant value), so that performance can be checked for different possible configurations. Rhinoceros, Grasshopper, ClimateStudio, Octopus, TT toolbox, and Energy plusTM software with plugins are used to conduct the optimization process. Genetic Algorithms are used to narrow down the optimization results and identify the best options that comply with the multi-objective goal. Predicted Percentage of Dissatisfaction (PPD) is also analyzed for the best options identified from the optimization process. The result shows the balanced option (best for both daylighting and energy) with changed materials satisfies the thermal comfort of users.

x Ceiling fans have been widely used for decades for providing thermal comfort in warm environments. They are an effective means of completely avoiding the use of energy-intensive air conditioning systems in milder environmental conditions and of reducing the use of such systems in more severe and hotter thermal environments. Ceiling fans can generate an immediate cooling effect on people, as they act on both sensible and latent heat exchange be-tween the human body and the moved air. However, one of the major potential limitations of ceiling fans is that they generate non-uniform velocity profiles, and their effect is highly dependent on the mutual position between body and fan. Thus, it is essential to carefully evaluate the position in which they are installed to maximize their cooling effect where needed by people. CFD is a powerful technique for investigating the air velocity field generated by different ceiling fan configurations. Due to its high demand for computational power and the need for having stable models, previous studies proposed different approaches to model ceiling fans in CFD with some simplifications. As the available computational power increases, so does the possibility of creating more realistic models, but too little is known about when the benefits produced by more complex models are overtaken by their computational costs. The aim of this study was to compare the results obtained by using two approaches to include the ceiling fan into a CFD model, namely a detailed model of the geometry of the fan and a simplified implicit approach that emulates the effect of the fan only. The results illustrate that (a) both models capture the main regions of the air flow, (b) the implicit model provided considerably more accurate air speed values, (c) the computational time of the model with blades is one order of magnitude higher, and (d) fan geometry and meshing are the most critical is-sues in the model with blades.

x In recent Italian Law, the DM 11/01/2017 about Environmental criteria, reference values for the acoustic indoor quality descriptors of public buildings are imposed. These refence values are in compliance with the national standards UNI 11532- 1 and UNI 11532-2. Part two of the series standard, in particular, describes the procedures and gives limit values for the acoustic comfort descriptors for schools. Regarding schools, adequate acoustic comfort targets are required in terms of in-door noise level and acoustic quality. Indoor acoustic quality targets refer to reverberation time (RT), Clarity (C50) and/or speech intelligibility (STI). The limit values for these indoor acoustic quality parameters, established by the national standards, are related to the measurement methods results; however, it is necessary to use prediction methods to estimate these parameters during the design phase. The aim of this study is to verify the prediction method accuracy used to determine intelligibility score. The study was developed to model the existing calculation method of speech transmission index (STI) in Matlab software to determine the acoustic speech intelligibility in school classrooms. A school building located in central Italy, in the Marche Region, was taken as a case study. This research aims to determine a correlation factor between the results of predictions and measurement speech intelligibility methods.

x One of the possible solutions for renovating building heating systems is the use of hybrid systems, which consists of coupling heat pumps with traditional natural gas boilers. Hybrid Heat Pump systems are typically controlled to run the heat pump when the outside temperature is not too low, maintaining acceptable costs and good energy efficiency levels. However, when buildings also have a certain level of thermal inertia, proper management of the hybrid system can allow some flexibility. Especially in presence of non-programmable renewable sources, the control strategy can play an important role to maximize self-consumption. The aim of this work is to assess the role of the control strategy in achieving this objective in relation to the cost reduction potential for energy bills. In particular, we investigate how much it is worth using an advanced control technique (e.g., a Model Predictive Control) compared to a Ruled Based Control to regulate the hybrid heating system of a residential building. The paper analyses a case study in which a building, equipped with Hybrid Heat Pump system assisted by photovoltaic panels serving a radiant floor, is controlled both through a Model Predictive and a designed Ruled Based Control. The objective of the controls is to minimize the energy bill for heating. The results are intended to assess whether the added complexity of the best performing model predictive control is justified by the magnitude of the performance increase that is obtained.

x The main Auditorium of Bologna was created inside the original monastery built during the 16th century by the Jesuits. In the following century, the building was modified to become a Catholic church by the architect G. Rainaldi. After the French invasion led by Napoleon during the 18th century, the church was adapted to fulfil different uses. Nowadays, the main hall, composed of three naves but having audience seats in the central one only, is used for celebrations and civil events organized by the University of Bologna. Numerical simulations have been undertaken considering two different scenarios: acoustic adaptation to become an auditorium and to become a conference hall. The model representing the existing conditions has been calibrated on the measurements undertaken across the seating areas. The two scenarios simulated have been compared with the existing conditions of the Aula Magna: the outcomes highlight an improvement in speech comprehension across all the seating areas by achieving the optimal range of each acoustic parameter analyzed. A historical background has also been introduced to understand the adaptation of the original construction to the different room functions assigned throughout the centuries.

x Adaptive façade systems offer the opportunity to improve building performance and user experience with their ability to adapt the façade configuration to the dynamic variability of the external environment. Nevertheless, the correct deployment of adaptive systems in real buildings is highly dependent on the ability to predict their performance. This is especially relevant in the case of Complex Fenestration Systems (CFS), which are characterized by a complex behavior both from a thermal and daylighting perspective. Often, such CFS are combined with airflow movement when the façade cavity is either mechanically or naturally ventilated, making the performance even more difficult to be characterized. The possibility to use building performance simulation tools to simulate the behavior of these systems integrated in a whole building is central for the proper use and the penetration on the market of these systems. In this framework, a naturally ventilated window with integrated venetian blinds was modeled in TRNSYS and compared with a FEM-based 2D detailed model, developed in COMSOL Multiphysics. Type56_CFS solves thermal calculation and uses the Bidirectional Scattering Distribution Function for describing optical properties of the façade. This model requires the inlet mass flow rate, which was assessed thanks to an ad-hoc implementation of ISO 15099. The numerical modeling of the coupled heat transfer and fluid flow with COMSOL allowed the TRNSYS model to be calibrated. The calibration was carried out by increasing the model complexity, focusing on the inlet ventilation flow rate parameter: (a) firstly, it was provided as an input to the Type56_CFS from the FEM-based simulation and then (b) it was calculated by the ISO 15099 internal model and pro-vided to the Type56_CFS. Using this methodology, it was possible to compare the ability of TRNSYS to simulate the thermal behavior of the naturally ventilated cavity against a FEM-based benchmark. Results show a difference of 5 % after the fine tuning of all TRNSYS-related parameters (40 % as uncalibrated starting value).

x The e-SAFE innovation project financed by the Horizon 2020 Programme and led by the University of Catania, is developing, testing and demonstrating an innovative combined energy-and-seismic renovation solution for Rein-forced Concrete (RC) framed buildings based on the addition of Cross Laminated Timber (CLT) boards to the outer walls, in combination with wood-based insulation. In this paper, the proposed renovation solution (called e-CLT) is investigated in terms of moisture-related risks, i.e., the mold growth and the increase in heat losses due to Liquid Water Content (LWC) within building materials. To this aim, dynamic simulations are performed by means of Delphin 6.1, thus including combined heat and mass transfer (HAMT) due to water vapor migration and accumulation. The results show that, although there is no significant risk of mold growth in the e-CLT for climate conditions prevalent in Northern Italy, the moisture content within the materials implies an increase by about 10 % in the heat losses if compared with a dry wall. Furthermore, inaccurate material properties and boundary outdoor climate conditions can affect the reliability of the results: for this reason, a more appropriate hygrothermal characterization of materials is recommended, as well as the identification of suitable climate datasets, which, however, are not always available.

x The reduction of the environmental impact of the building sector is one of the top priorities in the “climate change challenge”. As the primary energy consumption of the building decreases, a high level of indoor comfort must be maintained. Both thermal parameters, lighting, acoustic level, and indoor air quality affect indoor comfort. These aspects are fundamental, especially in school buildings, where a good level of indoor comfort can help student to stay focused. This paper proposes a methodology for a combined optimization of the energetic and the acoustic performance of a school building. A case study, located in the center of Italy, was analyzed. Firstly, the thermal and acoustic performance was determined. Then a list of interventions was hypothesized and simulated, involving both the building envelope, the lighting and thermal plants. Normalized acoustic insulation of partitions between adjacent rooms, acoustic insulation of the façade and reverberation time were evaluated. The outdoor and ambient noise levels were based on the main characteristics of the façade (type and stratifications of opaque and transparent components, ventilation system, etc.). Results show that the optimal combination of interventions reduces the CO2 emissions of 88.55 % and the global energy performance index of 85.2 %. The indoor sound pressure level due to traffic noise is reduced by 19 dB after acoustic insulation of the façade, while further treatments to indoor surfaces should be implemented to reduce internal reverberation time and to improve speech intelligibility. The combined optimization shows that the highest reduction of the global impact (89.2 %) is obtained by weighting 80 %/20 % the acoustic/thermal performance.

x This contribution provides a review on research and development activities that have been conducted in the field of highly-insulating windows with vacuum glass. In a joint effort with the window-producing industry, different novel solutions for vacuumglass-equipped windows have been studied. Thereby, different methodological approaches have been deployed, including the construction of technology demonstrators, performance measurements on laboratory test sites, and numeric thermal bridge simulation. As a result, the project consortium succeeded in the development, construction, and exhibition to relevant stakeholders in the industry of four, innovative window prototypes. These windows not only employ vacuum glass products, but also in part provide new operation kinematics, motorization, and the implementation of automated ventilation positions. Moreover, the U-values of the windows could be approximated to be around or below 0.70 W.m-2.K-1 (i.e., UWin-value) at pane thicknesses of less than a centimeter. The windows include turn windows to inside and outside, as well as a swing-operation window, and a window utilizing an offset- and slide-operation mechanism without visible railings. The contribution not only displays the final prototypes, but also highlights the methods and provides an outlook for future development in this area.

x The correct acoustic design of rooms such as classrooms, conference rooms and offices is of fundamental importance to ensure high speech intelligibility and to contain internal noise levels. The use of sound-absorbing ceilings alone is not always sufficient to guarantee adequate comfort, as the reflections between parallel walls could introduce unwanted phenomena such as flutter echo or the accentuation of modal resonances. One more issue is related to the use of Sabine or Eyring models, which could lead to an underestimation of the reverberation times. This article compares the reverberation time measured and simulated in two small rooms with (i) Sabine and Eyring models, (ii) two commercial simulation software and (iii) the EN 12354-6 standard method valid for rooms, with absorption not homogeneously distributed between the surfaces.

x The thermal and acoustic insulation of individual building elements such as walls, windows and systems for roller shutters significantly affects the thermal and acoustic insulation of a building. This paper considers the acoustic and thermal performance of the individual elements evaluated in laboratory with simulation of both the façade sound reduction index and thermal transmittance of a typical room. The scope of this work is to verify if there are any correlations between acoustic and thermal performance; for this reason, 4 types of opaque wall, 3 window systems for roller shutters and 5 windows for a total of 60 façade configurations have been considered and combined.

x Climate change effects on human activities have become more and more evident in the last few decades and human society is looking for new solutions to deal with such consequences. One of the measures that can be developed to tackle this problem is the development of the Sustainable Energy and Climate Action Plans (SECAPs), aiming at reducing the mutual impact between human activities and climate at municipal level. To develop such policies, an extensive study of the building stock, of its current and future performances, and its possible improvements is fundamental. Therefore, an energy analysis for a historical building used as a museum and situated in Trieste, a location included in the Interreg ITA-SLO Secap Project, is carried on in this work. The building represents a challenging task due to its historical nature and architectural features. The current climate for Trieste was represented through a Test Reference Year that was then projected into the future using different climate models. The building was numerically modeled, highlighting its main structural and plant features and usage patterns. Future projections for the climate of Trieste showed a general increase in temperatures for all the studied models, leading to a forecasted decrease in heating gas consumption and an increase in electricity-cooling usage of the base building. Regarding the refurbishment interventions applicable in accordance with the preservation regulations, the results show an obtainable reduction of both gas and electricity consumption for every climatic condition considered. However, the interventions proved not to be economically feasible, showing a too-long simple economic return on the investment.

x With the aim of reducing greenhouse gas emissions, more and more heat pump generators are being used in the residential space heating sector to replace traditional condensing gas boilers. This paper discusses the application to an Italian case study of the new draft of EN 15316-4-2, which provides a methodology for the calculation of the energy performance of heat pump systems used for domestic hot water preparation or space heating purpose. The case study involves a two-storey residential building equipped with several modulating air-to-water heat pumps. Two different daily profiles for heating were considered: continuous heating mode (heating system on 24 hours a day) and intermittent heating mode. Hourly building energy need for heating, calculated according to EN ISO 52016-1:2017, were used as input. The seasonal coefficient of performance (SCOP) of heat pumps analysed with an intermittent profile are 45.77 % higher on average than those in continuous heating mode, even if, in the intermittent system configuration, there is always an amount of missing energy. Finally, the results show that oversizing the heat pump leads to low SCOP and high non-renewable primary energy; while undersizing the heat pump leads to high SCOP but non-negligible missing energy values.

x Yves St Laurent Auditorium was built at the core of Morocco as part of the museum that honors the French fashion designer. The interior and architectural design of the Auditorium evokes the colors and the materials typical of Marrakech, with bricks and wood being the primary structural resources of construction there. The shoebox envelope was modeled to accommodate ergonomically the select audience attending specific performances oriented towards fashion design. The sound diffusion was realized with the application of quadratic residue diffusers (QRD) installed on all the walls in a vertical configuration. These acoustic panels increase the phenomenon of sound scattering in all directions, making listening very warm and comfortable. This paper deals with the assessment of the main acoustic parameters gathered by the acoustic simulations of a digital model. The simulated values were compared with the optimal values of performing arts spaces of similar room volume.

x The Bonci theatre in Cesena was built in 1846, becoming a stable public construction after a period when theatrical shows used to be privately performed inside aristocratic palaces. The architectural design, to be composed of 5 orders of balconies and the shape of the plan layout follow, in reduced dimensions, the Alla Scala theatre in Milan. Acoustic measurements were taken across the stalls and inside some selected boxes according to BS3382-1. The main acoustic parameters gathered by the measured values were compared with the acoustic simulations of a 3D model, which faithfully reproduces the Bonci theatre. The scope of this paper is the analysis of the acoustic behavior of the Bonci theatre, which can be used to calibrate a digital model before the executions of any acoustic simulations. This practice is fundamental for the accuracy of the results, which shall be carried out by comparing the measured with the calibrated values. A review of the historical background has been introduced to allow an appreciation of the architectural value of this cultural heritage.

x The Communal Theater of Bologna was built in 1763, after a fire destroyed the previous Renaissance construction. The project was assigned to the architect Antonio Galli Bibiena, who belonged to a family of artists and scenographers. The interior design represents Baroque style, with its four orders of balconies surmounted by a top gallery. Acoustic measurements were carried out inside the theater in line with BS3382-1. The values measured were compared with the acoustic simulations of a digital model reproducing the shape and volume of this cultural heritage. The historical background of the building has been summarised to aid understanding of the construction development overseen by Antonio Galli Bibiena.

x Energy retrofit of existing buildings is based on the assessment of the starting performance of the envelope. The procedure to evaluate thermal conductance through in situ measurements is described in the technical standard ISO 9869-1:2014, which provides two alternative techniques to process collected data: the Average Method (AM) and the Dynamic Method (DM). This work studies their effectiveness using virtual data from numerical simulations of three kinds of walls, performed using a Finite Difference model. The AM always provides acceptable estimates in winter, with better outcomes when indoor heat flux is considered in every case except the highly insulated wall. Summer conditions do not lead to acceptable measurements, despite the fulfillment of the check required by the standard. The DM results show acceptable estimations of the thermal conductance in both climates, for most of the virtual samples considered, although critically depending on some parameters of the DM that are left to the user’s discretion, without strict indications by the standard. This work highlights a possible approach for overcoming this issue, which requires deeper future investigation.

x Natural ventilation can be an effective means of providing healthy and comfortable indoor environments while minimizing energy consumption. However, the use of diverse types of windows and control strategies usually leads to different indoor local thermal conditions. Previous studies have focused on indicators of ventilation effectiveness, but too little is known about the spatial variations of thermal comfort generated by different window opening styles. CFD is a powerful numerical modeling technique to compare the air distribution within a room, and therefore to evaluate the performances of different type of window in terms of delivered thermal comfort and indoor air quality (including local effects). Thus, the aim of this research is to investigate the effectiveness of diverse type of window, such as bottom-hung, horizontal pivot and top-hung fan-light for single-sided wind-driven natural ventilation. In this study, two wind speeds and two wind-window angles were investigated, for two weather conditions typical for the region of South Tyrol, Italy. In this study, thermal comfort was evaluated based on standards EN ISO 7730 and ASHRAE Standard 55. Using transient RANS CFD simulations, the performance of different window configurations for the different boundary conditions were numerically evaluated. The boundary conditions, geometrical simplifications, grid-independence tests, discretization, and basic principles for a transient simulation were chosen based on previous studies and then tested to ensure the correct modelling of a wind-driven natural ventilation flow. The results show 25 %-200 % higher incoming air-flow when the wind enters at an acute angle as compared with perpendicular wind. Furthermore, the horizontal-pivot window reports a 39 % higher incoming airflow when compared with bottom-hung window style, while the draught risk in winter conditions was similar for both.

x This paper aims at presenting a methodology for the management of multiple energy simulations of complex building assets. The educational buildings of the Milan municipality have been chosen as case studies: several retrofit strategies are tested on hundreds of buildings, evaluating their feasibility and calculating the potential energy savings. The results, obtained with dynamic simulations using SketchUp and the “Intelligent Community Design (iCD)” plugin, are then compared with a static calculation implemented on a regional scale in Lombardy. Besides, a methodology for the collection of the input parameters is proposed, based on the combination of data coming from several sources.

x The 2010/31/EU Directive established a comparative methodology framework to determine minimum energy performance requirements based on a cost-optimal approach. This research investigates the cost-optimal outcomes resulting from the application of the monthly quasi-steady state method (UNI/TS 11300-1) and the simplified hourly dynamic model (EN ISO 52016-1), both aimed at determining the thermal energy needs for space heating and cooling. The technical building systems have been modelled by means of a monthly steady-state method, in agreement with the UNI/TS 11300 series. The global cost has been calculated from a financial perspective according to EN 15459-1. The proposed methodology has been applied to two buildings that differ in their climatic zone, construction period, and intended use. For this purpose, a single-family house located in Palermo and an office building sited in Milan have been assessed. To investigate the deviations between the two energy models, the results in terms of packages of energy efficiency measures and global cost have been compared.

x The Covid-19 pandemic revolutionized the way of designing buildings, which should be created to improve health conditions and limit the spread of contagion. Among these, schools certainly need special attention. To improve indoor conditions, the first step of this study was conducted by simulating three classrooms having different ventilation strategies, using a CFD analysis. Then the infection probability was calculated using the Gammaitoni-Nucci model to analyse the risk in the class-rooms according to different ventilation and building characteristics. The study showed the need for providing adequate ventilation to ensure healthy conditions for the students. Furthermore, the infection probability was calculated considering non-uniform environments, which can result from various air distributions in the classroom due to local non-uniformities. The configuration obtained from the CFD analysis was then compared to the standard condition. which considers the classrooms as uniform environments. This allows an understanding of the effective conditions to which students are exposed and to comprehend whether the classical models do not risk underestimating the infection probability. This study provides a new methodology for airborne transmission risk assessment in non-homogeneous environments and supports designers with a new tool to evaluate HVAC systems layout and classroom operation.

x The design of nZEB buildings, as well as the implementation of retrofit interventions in existing structures, are essential tools for reducing energy consumption in buildings and increasing decarbonization of the building sector. To describe the effectiveness of a retrofit intervention, in addition to the analysis of the benefits in terms of costs and energy savings, an environmental analysis should also be performed, introducing various indicators, such as energy and environmental payback times. In this article, we considered a residential building located in Montemarcello (Liguria, North-west of Italy) that had been subjected to a refurbishment and an expansion, with the aim of evaluating the energy and carbon savings achievable due to the interventions carried out. The life cycle analysis approach was applied to calculate the environmental payback times. The main purpose of this work is the application of an integrated approach to assess the economic, energetic and environmental convenience of retrofit interventions during the entire life cycle of the building, underlining the importance of considering LCA and environmental aspects to achieve decarbonisation of the construction sector. The results show that energy and environmental payback times are lower than the useful life of the building and of its components, and that LCA proves to be a strategic methodology for studying the problems deriving from global warming and energy supply in the building sector.

x The noise from wind turbines is generally assessed according to ISO 9613 in order to preserve the internal noise levels of the nearest sensitive receptors. Following the standard requirements, the wind turbines are considered point sources with an attenuation decay equal to 6 dB by doubling the distance. These indications should be taking into account also the air absorption at different octave bands and the gradient effects due to outdoor environmental conditions. This paper deals with the comparison of some acoustic measurements carried out in Campania (Italy) with the theoretic outcomes obtained in line with the standard ISO 9613. Different types of wind turbines have been assessed, based on a variety of power supply, distance between source and receiver and gradient of wind speed and direction. The surveys have been undertaken inside the nearest sensitive receptors with the conditions of open windows. The results highlight a drift between results, where the calculated are found to be lower than the measured-on site, underestimating the real environmental conditions.

x The risk analysis of moisture-related damages can potentially be carried out with the use of heat and moisture transfer simulations. These models require weather files as boundary conditions but, for most locations, the only weather files available are Typical Reference Years, for instance the TRYEN defined in accordance with EN ISO 15927-4:2005. These reference years do not provide the critical conditions that should be used in risk assessments. In this work, two procedures to define Extreme Moisture Reference Years (ERYm1 and ERYm2) are presented. ERYm1 and ERYm2 are designed to generate critical weather files to be used in simulations for the assessment of moisture related risks. The presented procedures are structure-in-dependent and suitable for risk assessments that involve high air moisture content and low air temperature values. In order to assess the capabilities of ERYm, five types of walls with different materials are simulated, considering three Italian climates (those of Gemona del Friuli, of Legnaro and of Trento) and four wall orientations (North, East, South, West). The results of simulations with ERYm1 and ERYm2 as weather files showed higher wall moisture contents and interstitial moisture accumulation risks than those with TRYEN. This suggests that ERYm could be used as a valid alternative to the TRYEN in decision making frameworks and legislations that cannot include the ad hoc definition of a weather file for each structure, exposure and location.

x Wood has become an appealing solution in the building sector compared with traditional materials such as stone, steel, concrete, and brick for several reasons: it is more sustainable, it provides good thermal properties, and allows for fast construction processes in dry-assembled applications. However, wooden buildings in the Mediterranean area are still not very widespread, mainly due to social prejudices about their resistance to seismic events and doubts concerning durability and fire resistance. The paper focuses on the validation of an energy model of a sustainable wooden building that is the prototype of a research project aiming at producing advancement in the development of residential settlement models with solutions to implement in new single or multi-story buildings. The single-family building is located in the province of Cosenza (South Italy). The building was equipped with a monitoring system for the acquisition of quantities of interest for thermal analysis and was subject to an experimental campaign conducted in the summer of 2021. The building was then modeled in the TRNSYS environment accounting for the detailed modeling of solar radiation. Simulations were performed in free-floating conditions, allowing the thermal model to be validated. Then, further energy simulation allowed an evaluation of the thermal performances of building in different Italian localities, allowing the viability of wooded solution in a Mediterranean climate to be demonstrated.

x The development of the electric power grid addresses the needs deriving from the growing use of renewable sources and from the dispatching flexibility required by mobility electrification. New infrastructures to control the grid parameters and configuration are also being installed in the urban environment, and the relative equipment must generally be enclosed in technical rooms to prevent unauthorised access. Such enclosures must fulfil two conflicting requirements: on the one hand, they must be closed enough to reduce the potentially disturbing noise emitted by the inner equipment, and, on the other hand, they must feature openings for natural ventilation, as high-voltage elements may get damaged due to overheating. Therefore, cooling and sound insulation aspects must be properly integrated during the design phase, keeping an eye on other potential issues, such as condensation. This paper presents a possible strategy of dual acoustic and thermal simulation applied to the design of a new high-voltage control system that allows the expensive technical equipment to be safeguarded while reducing the risk of noise annoyance.

x Moisture in air is essential for human life. It drives all physiological processes and determines occupant wellness. As a crucial parameter of Indoor Environmental Quality (IEQ), it is regulated by building typology and its constituent materials. Besides affecting heating and cooling energy requirements, indoor moisture also determines occupants' comfort and health. Occupant comfort, commonly referred to as thermal comfort, is paramount for building and indoor environment design. Currently available building simulation tools majorly incorporate temperature-related comfort models like PMV, PPD, and adaptive thermal models. In conjunction with temperature, indoor moisture levels impact occupants' skin-related and respiratory comfort, resulting in health issues such as skin irritation, allergies, respiratory infections, asthma, etc. Humidity has not been adequately dealt with in comfort studies. This study proposes a novel computational approach derived from an existing model to explain and assess humidity-related comfort in buildings. The study also involves real-time monitoring of indoor-outdoor temperature and humidity and occupant comfort-votes. The hygroscopic properties of building materials impact the regulation of indoor moisture, thereby impacting occupant comfort and health. This article examines humidity-related comfort aspects between conventional and vernacular building typologies. Results from the simulation have been used to explain the comfort votes obtained from an on-field survey of occupants. Skin temperature and wettedness derived through energy balance between the human skin and the indoor air parameters can be used as an indicator to assess skin-related comfort in indoor environments. Comfort is an essential indicator of wellness in an indoor environment. Clarity on approaches to evaluate different aspects of comfort attributed to building materials is crucial for built environment design for occupant wellness. Incorporating humidity-associated comfort parameters in building simulation tools could be beneficial in selecting materials for building design to cater to varying functionalities and health co-morbidities.

x End-of-Life, or discarded, Solar Photovoltaic panels are rising in huge numbers every year throughout the world. This is of grave concern as the environmentally safe handling of EoL-PV is not yet established fully. We propose a novel approach to upcycle End-of-Life (EoL)-PV as a building material that can extend the life of PV by another 2~3 decades. PV panels are a multi-layered laminate of different materials. In the course of environmental exposure and use, degradation induces variation in the optical properties of EoL-PV. Variations in thermal properties have not been explicitly examined, which has a bearing on the thermal performance of a building when integrated as a building material. This work studies the influence of the thermal conductivity and solar transmittance of PV panels on the surface temperatures using a steady-state energy balance model. Also, through the whole building simulation, the implications on the mean radiant temperature and the heating/cooling load of the building by using EoL PV compared to a new PV are understood. Other factors, like the area of PV to wall ratio, seasonal changes, and climate zone are found to play a role in the relative changes in the MRT and Heating/Cooling Load attributed to EoL-PV integration in buildings.

x The increasing energy demand of our buildings is putting stress on the building systems and energy grids in terms of need for efficiency improvements. The maximization of the overall performance requires a multidisciplinary approach towards seeking innovative solutions to help reduce the building loads. In terms of efficient energy planning, the building design phase has often been often disregarded or looked at from a single point of view. In this case, research places its attention either on the performance of the opaque or transparent envelope to define optimization criteria. A comprehensive analysis of the impact of different passive solutions on the energy demand of buildings with different uses is the core of the present paper. The main goal is to define design guidelines for the integration of simple to complex passive configurations into the building design to help reduce the heating demand by better exploiting solar radiation. The paper gathers data from 384 simulations, on different test buildings, with the permutation of various design parameters, including window-to-wall ratio, wall heat transfer coefficient and heat capacity. Simulations were run in two different locations, typical of southern and northern Italian climate conditions, for both residential and office use. After the best solutions according to the heating or total energy performance over a nominal year were highlighted, the guidelines were applied to a case study. The aim is to determine a methodology to properly integrate passive solutions on the basis of energy performance. This performance, indeed, constitutes a trade-off of the potential of passive systems to understand when it can be profitable to integrate these. The building analyzed, a cohousing project still in the design phase, showed that 10 to 16 % of the total energy demand can be saved. The energy saving is reached by simply integrating and declining the passive configuration suggested with marginal modifications to the initial design.

x This study is the second step toward the development and prototyping of a Personal Comfort System for tertiary sector working environments. The entire industrial sector, and, in particular, offices, have seen changes in working habits, with a large increase in smart working also due to prevention of COVID infection. The chance to partialize the HVAC system and maintain rooms in an underconditioned state is the obligatory way towards reducing energy waste, providing each workstation with an independent system that guarantees the operator's comfort conditions. The goal of the second step presented in this work was to size and optimize the radiating desk, with the aim of testing an experimental demonstrator. A LHP was chosen to bring heat from the source to the desk, decoupling the heat generation and heat distribution system, without the need for additional parasitic power consumption or moving parts, adding to the innovation of the proposed design. The ergonomic optimization of the surface and its power reduction did not affect its ability to improve localized comfort, since the operators’ conditions move from a slightly cold to a neutral situation. Moreover, no discomfort due to vertical temperature differences or radiant asymmetries were found. Therefore, the next research step will lead to prototype creation and its analyses, conducted in a climatic room to test if the distribution system can satisfy comfort thermal requirements with probes as well as real users.

x In building refurbishment projects, efficient technologies such as heat pumps are increasingly being used as a substitute for conventional technologies such as condensing boilers, with the aim of reducing carbon emissions and determining operational energy and cost savings. Measured building performance, however, often reveals a significant gap between the predicted energy use (design stage) and actual energy use (operation stage). For this reason, a scalable energy signature modeling approach is presented in this paper to verify building energy performance from measured data. Regression models are built with data at multiple temporal resolutions (monthly and daily) and are used to verify the performance improvement due to smart heating controllers (TRV) and Gas Absorption Heat Pumps (GAHP). The capabilities of energy signature analysis are enhanced by including additional variables in the modeling process and by running the models as “digital twins” with a rolling horizon of 15 days of data. Finally, a regression model for GAHP technology is developed to validate the results measured in the monitoring process in a comparative way. The case study chosen is Hale Court sheltered housing, located in the city of Portsmouth (UK). The results obtained are used to illustrate possible extensions of the use of energy signature modeling, highlighting implications for energy management and innovative building technologies development.

x The Amintore Galli theater in Rimini re-opened in 2018, after more than 60 years of inactivity. Its acoustics have been studied in depth, starting in 2009 until the re-opening of the theater. This paper analyses the following different steps of the acoustic design of the Opera House: the analysis of the acoustics of similar other theaters, the design of the acoustics of the new main hall, the analysis of the acoustic characteristics of the diffusing panels in the theater, and the acoustic design of other rooms, including the rehearsal room. Moreover, this paper reports some of the most relevant results of the acoustic surveys conducted after the re-opening, comparing the values of some acoustic parameters obtained after the simulation processes, and the values of the same parameters during the final validation of the theater.

x Building energy modeling based on data-driven techniques has been demonstrated to be effective in a variety of situations. However, the question about its limits in terms of generalization is still open. The ability of a machine-learning model to adapt to previously unseen data and function satisfactorily is known as generalization. Apart from that, while machine-learning techniques are incredibly effective, interpretability is required for a "human-in-the-loop" approach to be successful. This study develops and tests a flexible regression-based approach applied to monitored energy data on a Passive House building. The formulation employs dummy (binary) variables as a piecewise linearization method, with the procedures for producing them explicitly stated to ensure interpretability. The results are described using statistical indicators and a graphic technique that allows for comparison across levels in the building systems. Finally, suggestions are provided for further steps toward generalization in data-driven techniques for energy in buildings.

x The energy demand of buildings plays an important role with regard to energy conservation objectives as well as reduction of greenhouse gas emission. The well-established building energy certificates provide essential information concerning the thermal quality and resulting energy demands of buildings in general. Hence, related Austrian regulations and standards specify a demand-orientated calculation method based on construction and material data together with standardized usage profiles, as well as a location-related weather data set. This method is also applied in the case of existing buildings, which differs from some other European countries, where certificates represent real energy usage and provide a comparison with similar buildings in terms of construction period and usage. However, it is not guaranteed that an energy demand certificate according to Austrian standards is able to represent the actual energy use of existing buildings, a circumstance that is typically referred to as ‘energy performance gap’. In this context, we conducted a comprehensive comparison of real energy consumption and the certificate-based energy demand predictions for a number of buildings located in and around the city of Vienna, Austria. Specifically, 15 residential building complexes with nearly 1400 units were selected, involving a large variety of building construction dates and their thermal quality. The buildings were analyzed in detail based on historic energy consumption data from 2011 to 2017. The paper provides an overview of the real energy performance together with a detailed analysis of the discrepancies between actual energy use and certificate-based estimations. Generally speaking, the buildings with a higher energy standard and lower demand displayed higher discrepancies (ex-pressed in terms of relative deviations) than older buildings with higher energy demand.

x Referring to the circular economy model, end-of-life household materials (EoLHM), such as packaging and clothes, could be converted into building elements with thermal and acoustic properties; for example, they could be converted into panels to be installed indoors for building refurbishment. Given the high availability almost anywhere, panels made of EoLHM would represent an alternative to commercial insulating materials that, even though relatively cheap, cannot be afforded by disadvantaged people. This paper presents a multidisciplinary analysis aimed at the characterization of polyamide 6.6, obtained as a waste from the production of non-surgical face masks. The research focuses on the thermal and acoustic properties of the material. The properties have been determined experimentally through the guarded hot plate method hot and the impedance tube technique. Then, the influence of the panel's position on the indoor operative temperature and the reverberation time has been analyzed through numerical simulations. Results show that, from the thermal and acoustic point of view, this waste is suitable for the realization of building panels, and the performance depends on the density and the thickness of the material. However, aspects such as fire resistance and the containment of the material need further investigation.

x This paper focuses on the profitability of demand-side management strategies developed for a single-dwelling mechanical ventilation plus radiant floor system. Energy savings and comfort indicators are quantified for a number of control options, including demand-controlled ventilation and temperature setbacks. The assessment is based on numerical energy simulations conducted in TRNSYS for the climate of Bolzano (Italy). To perform the simulations, numerical models of the energy system and the reference dwelling were developed. Based on the analysed climate and building, it was found that demand-side management strategies can have a significant impact on the energy consumption and time distribution of energy loads: demand control ventilation allows the achievement of consistent energy savings in the electrical consumption of the fans (up to 37 %), whereas the use of an adaptive dehumidification setpoint can lead to savings within the range of 10 % in summer electrical consumption. The use of non-occupancy temperature setbacks does not show a significant impact on the annual thermal demand, although the time pattern of the loads is considerably affected, with a cascade effect on the performance of the air-to-water heat pump. The use of the climatic curve parameters at the generator allows an improvement of the electrical performance of the heat pump, increasing the SCOP of more than 20 %.

x The market for lightweight construction systems is growing rapidly due to their potential in terms of prefabrication, ease of transportation and assembly. However, given their thermophysical properties, these types of structures present a limited thermal capacity that may reduce their performance in terms of comfort and energy consumption during the hot seasons. The present paper, through a series of computational fluid dynamics (CFD) simulations, offers a numerical assessment of the performance of an existing lightweight steel-framed building selected as a case study. The data required to perform the simulations are collected with a deep monitoring campaign and the building is analysed in its current state (actual conditions of use) and after the application of simulated passive cooling strategies. The role of natural ventilation, both day and night, is explored by investigating different opening/closing configurations of external windows and internal doors. Moreover, the positive effects of surface thermal mass and shading systems are numerically validated. The results, although limited to a specific context of analysis, show that, with appropriate adaptation strategies, even in lightweight buildings, occupants can achieve adequate levels of comfort, thus reducing the need for cooling. A combined and weighted use of passive solutions results in a reduction of about 3 °C in the average daily indoor temperature. Ventilation at night and solar shading during the day make a steel-framed building as comfortable as a massive one, both with regard to the internal surface temperature of the building components and to the discomfort indices. Changing the mass of the interior cladding of a wall, ceiling or floor, for example, from plasterboard to cement board, is another effective cooling strategy.

x The present study deals with the energetic optimisation of Domestic Hot Water (DHW) system in a residential building located in Catania, Italy. Each dwelling is equipped with a specific decentralised tank with an internal heat exchanger which is connected to a 2-pipe hot water network system for tank charging. The technical water is produced by an Electrical Heat Pump (EHP) coupled to a central storage tank. The energy performance analysis of the DHW model is evaluated by means of dynamic simulations under three different scenarios of charging the decentralised storage tanks by circulating pump unit: Pump activated during daytime, activated twice a day, and activated three times per day. The results obtained allow an evaluation of the DHW consumption profile, temperature variation in central storage and decentralised tanks, and the annual electrical/thermal energy analysis. The results indicate that the activation of the circulating pump during the day leads to an achievement of the highest amount of thermal energy, as well as having minimum temperature oscillation in both central storage and decentralised tanks. However, these advantages are at the cost of consuming much more electrical energy by the heat pump and up to 29 % higher emissions of CO2. The best scenario in terms of energy-saving and CO2 emission is the case in which the circulating pump works twice a day, consuming annually 5,832 kWh less electrical energy, compared to the case of an activated pump during the day.

x One of the most significant repercussions of greenhouse gas concentration increase has been the global rise in temperature, resulting in drastic changes in the climate. According to this background, buildings are not only contributing to climate change, but they are also being affected by it, as climate change will raise the risk of overheating and cooling demand in buildings. Therefore, assessing and communicating resilient cooling and overheating protection solutions is inexorable. This paper aims to analyse the energy efficiency and climate resiliency of three passive cooling solutions for Italian residential buildings in future climates. Simulations have been performed using EnergyPlus for the pre-retrofitted condition (without insulation and conventional heating and cooling systems) and the retrofitted building (with insulation and a reversible heat pump for heating and cooling). Results show that buildings will be subject to an increase in cooling loads, electrical energy consumption for cooling, and overheating risk due to climate change. The ultra-selective double-glazed window is found to be more climate-resilient in comparison with roller blind and cool roof tiles. Besides, combining these three cooling technologies can guarantee the best future energy performance for each period. However, the overheating risk during the power outage still exists, especially for the post-retrofitted building. These findings have significant implications for understanding how analyzing multiple factors is essential to guarantee the climate resilience of cooling systems in a holistic way.

x Many studies have shown how controlled natural ventilation has multiple benefits on the health of people and the buildings in terms of indoor air quality (IAQ) and thermal comfort, as well as on the energy consumption of the building. However, unfavorable outdoor environmental conditions can limit the use of solely natural ventilation and, for this reason, it is often necessary to resort to mixed-mode ventilation. The aim of this research is to demonstrate the potential of mixed-mode ventilation strategies in comparison with the performance of controlled natural ventilation and mechanical ventilation applied separately, in the context of a dwelling located in a multi-family house in Bolzano (Italy) during the summer season. Dynamic simulations were performed, developing a room-by-room coupled thermal and airflow model of the dwelling in TRNSYS and TRNFLOW to characterize its thermal behavior and the natural airflows. The study analyzes and compares three different scenarios: (1) only controlled natural ventilation (CNV), (2) only mechanical ventilation (MVT), (3) a combination of the two (mixed ventilation strategies, MIX). In this work, the controlled natural ventilation strategies are designed with a twofold aim, which is (a) to improve the indoor thermal comfort, reducing the overheating risk thanks to ventilative cooling, and (b) to improve IAQ by removing indoor airborne pollutants coming from indoor sources. The first results show that (a) CNV effectively reduces the overheating risk, also achieving excellent IAQ levels; (b) MVT allows acceptable IAQ conditions and good water vapor removal, while overheating could become an issue in terms of duration and intensity. In addition, there is the electricity consumption associated with MVT; (c) in most cases, mixed ventilation provides excellent performance in terms of IAQ and thermal comfort, compared with the former strategies. Overheating is well managed, and the electrical consumption of MVT is limited.

x Building energy simulations are important for assessing the performance of buildings and for designing solutions aimed at reducing energy consumption and carbon emissions. Many software tools perform these simulations, focusing on systems operations and energy losses and gains. When it comes to modelling historical buildings, the simulations could be also used to estimate the risk of damage and decay processes. This paper presents preliminary results based on twelve standardised exercises of increasing complexity for the comparison of microclimate simulations modelled through three whole-building hygrothermal dynamic simulation (BDS) software tools, specifically IDA ICE, WUFI PLUS and ENERGY PLUS. Different to the testing procedures already available, this research focused on the physical variables that are relevant for conservation of historical buildings (i.e., temperature (T) and relative humidity (RH)). Starting from Common Exercise 0 (CE0), seven simulations were customised to capture differences in T values. Then, five building models were specifically conceived to consider some typical features of Historical Buildings (HB0): small window size, heavyweight structures, low insulation of roofs, large volume and free-floating conditions. In the case of CE0, good agreement was found in the simulation of indoor T. In addition, detailed windows reduced the discrepancy in T results compared with the use of simplified windows. In the case of HB0, small windows slightly affected the microclimate simulations regardless of the number of transparent elements and their position. RH variability was driven only by T, as the partial water vapor pressure was affected only by infiltrations through the building. To conclude, the comparison allowed a highlighting of some critical points due to different model implementations, such as weather file timestamp interpretation, window models or irradiation calculations. HB0 models could be used for software and model comparisons, new software testing and training activities.

x Urban-scale evaluations of aerodynamic and morphological parameters allow correction of the wind speed within the urban boundary layer, as the wind profile is strongly influenced by the presence of roughness elements. This can have important implications for defining urban strategies for the reduction of buildings’ energy consumption and the improvement of air quality and liveability of outdoor spaces. Among the current models for assessing the air flow rate by natural ventilation in buildings at urban scale, this study aims to define a GIS-based methodology, using existing databases and an open source QGIS plug-in. From a digital surface elevation dataset, and considering prevalent wind directions, the displacement height (zd) was determined. The wind speed was corrected, applying the logarithmic or turbulent laws of wind profile, respectively, above and below zd. This method could determine the spatial distribution of wind speed, considering each building façade characteristics and its surroundings. Resulting wind pressure on wind-ward and leeward façades drives the air flow rate inside the buildings. Further developments of this work will improve the air flow modelling in buildings with other tools for applications at urban scale.

x The built environment generates nearly 40 % of annual global CO2 emissions. To reduce these emissions, alternative materials able to store CO2 have started to be used in the construction sector. In the case of hemp concrete, part of this storage occurs during its service life leading to a potential decrease of indoor CO2 levels. Assuming that CO2 is used to control ventilation rates in certain buildings, the use of this material might lead to lower ventilation requirements and, thus, reduced energy consumption. The aim of this work was to develop an energy model including the CO2 sequestration capability of hemp concrete to estimate the potential energy savings derived from its use in a typical residential building in South Tyrol with CO2-based demand controlled ventilation. This result was later compared with the energy consumption of the same building made of clay bricks and the influence of air infiltration on indoor CO2 levels was also evaluated. The results obtained from the simulations showed that indoor CO2 levels were always lower in the hemp concrete buildings compared to the building made of clay bricks. However, in hemp concrete buildings with high air infiltration rates, the effect of the CO2 absorption by the hemp concrete wall might be negligible. The energy required for the mechanical ventilation to maintain the CO2 levels under the 1200 ppm threshold was estimated to be 0.28, 0.02 and 0.01 kWh/(m2 yr), for the clay brick with low infiltration, hemp concrete houses with low and high air infiltration, respectively. Therefore, the operation of hemp concrete buildings with CO2-based demand-controlled ventilation may have a slightly lower energy consumption as well as environmental impact than the equivalent clay brick buildings.

x Improving the performance of buildings is a core pillar to attaining future energy and environmental goals in different countries, considering that the building sector is a major contributor in terms of both energy consumption and carbon emissions. These ambitious goals and the call for smarter, energy-efficient, and flexible buildings have called for innovative and scalable energy and indoor thermal comfort modeling and prediction approaches. This work presents a fully automated and scalable solution using Artificial Neural Networks to forecast indoor room temperatures in buildings. A case study of an 8500 m2 university building in Denmark was considered for testing and evaluating the proposed approach. An extensive dataset was constructed with sensor data from 76 rooms that contain both readings on indoor temperature, CO2 concentrations, and actuating signals on radiator valves and dampers, as well as outdoor ambient conditions. Using this dataset, a well-performing architecture is identified, which provides accurate temperature predictions in the various rooms of the building for prediction horizons of 24 hours.

x Building energy simulations are a key tool in designing high performance buildings capable of facing the future challenges and in helping emission reduction targets to be met. Currently, thermal properties of materials used in most building energy simulations are assumed to be constant and not dependent on moisture content and temperature. Heat and moisture dynamic transfer models allow a simulation of building envelope performance considering thermal resistance reduction due to moisture effects. These models are generally considered more accurate than the heat transfer models, and they could be used to simulate the heat transfer (increased by water vapor storage) and the moisture buffering effect on the indoor environment. For the simulation to be performed, hygrothermal material properties should be known as functions of moisture content. Nevertheless, hygrothermal material properties are rarely available and correlations from the literature have to be used. In this study, the moisture storage curves of CLT, OSB and two types of wood fibre insulation have been measured with a dynamic vapor sorption analyser. The other hygrothermal properties are estimated from values measured in previous studies or taken from the literature. The simulations of two small single room buildings in four Italian locations are performed with the software EnergyPlus, considering an ideal HVAC system, to calculate the heating and cooling needs of the building. The HAMT (heat and moisture transfer) module of EnergyPlus is used. With the results presented in this study, it is possible to evaluate how an approximated curve affects the results of a whole-building simulation in terms of wall average water content, indoor air relative humidity and heating/cooling loads.

x The nZEB target is increasingly becoming one of the main objectives in building renovation, but a unique nearly-Zero Energy Building definition is not explicitly available in the 31/2010 EU directive, the so-called “Energy performance of buildings directive”. Nevertheless, the technical implementation of the nearly-Zero Energy Building concept into defined constraints and requisites is a determining factor for the consequences of energy-economic performance. In fact, in the renovation process of a building, different technical requirements lead to different design solutions that affect investment and operative costs, as well as energy performance. Through an optimization process based on dynamic simulations for energy and economic performance assessment, a comparison between different approaches for the nZEB building retrofit for a demo-case building has been performed. First, an energy target which is stricter than the nZEB standard is examined. In particular, the so-called “Positive Energy Building” approach, consisting of the design of a building that produces more energy than it consumes in the overall year, is evaluated. Then, the results of the Positive Energy Building target are compared to a nearly-Zero Energy Building approach in which self-sufficiency is promoted, instead of the energy production/consumption balance. Also, the nearly-Zero Energy Building target promoted by the Italian legislation has been evaluated, comparing the result of a plausible implementation with the other more stringent approaches. The simulation work has been aimed at comparing significant Key Performance Indexes, regarding both energetical and economical aspects. In particular, initial investment costs, expected net present value of the investment after 25 years and energy performance indexes have been evaluated. The discussion demonstrates that, according to the assumptions adopted for the investment and energy costs, the Positive Energy Building target is excessively economically inconvenient for a renovation intervention of this type. Moreover, designers should prioritize the self-sufficiency of the building energy system with respect to the production/consumption yearly ratio. Finally, the discussion demonstrates that a renovation design in accordance with the Italian nearly-Zero Energy Building target is eco-nomically sustainable but the PV system size to meet the minimum requirements could be non-optimal.

x Most existing cities were not designed to exploit wind and air displacement phenomena to ensure pollutant dilution and enhance the effectiveness of natural ventilation of the built environment. Although this problem is well known in the literature, the majority of previous studies focused on real case studies or on parametric layouts often characterized by high-rise buildings, which are not typical for most Italian and European cities. In this framework, the goal of this research was to perform a preliminary CFD parametric study on street canyons with low- and medium-rise buildings, focusing on the different parameters impacting outdoor air displacement in an urban layout. Seven different configurations of street canyon were simulated with ANSYS Fluent, focusing on the air displacement around a low-, medium- or high-rise target building, located at the beginning, at the end, or in the middle of the street canyon, respectively. The velocity and pressure contour plots were analysed to understand the behavior of airflow around the buildings in the different configurations, discussing in such a way the natural ventilation potential.

x This work deals with the design of an indoor environment dedicated to autistic individuals, who may suffer from hypersensitivity to acoustic stimuli. Specifically, in this volume customized pieces of furniture are included, containing smart sensors, designed to help people with cognitive deficits to live an independent life. Among the indoor comfort aspects, the acoustic requirements have been investigated, in order to guarantee both the optimal functioning of the acoustic sensors and the acoustic occupants’ well-being. The optimal indoor acoustic levels are based on a literature review. Measurements are performed in order to calibrate a 3D acoustic model. Then diverse scenarios are analysed, and an optimized configuration is proposed and realized. The model is then validated with the final acoustic measurements, which confirm the designed results.

x Energy renovation of existing buildings represents a fundamental action for achieving the objectives aimed at overcoming the climate crisis. However, several difficulties are encountered in building refurbishment. Among these are the high costs and long construction times, the invasiveness of interventions, which often prevent the usability of the building, and the impossibility of providing maintenance and verifying degradation of the underlying layers of the envelope. Regarding the systems, retrofit often causes substantial alterations to the building aesthetics, affecting its original character and defacing the surrounding environment. Furthermore, the integration of renewable sources is often hard to implement. The I-BEST system (Innovative Building Envelope through Smart Technology) is an innovative multifunction façade system for the redevelopment of the existing building stock, which aims to overcome these limits by offering a valid response to the growing demand for building “recladding”. The system consists of sliding, modular and multi-functional panels, supported by a metal and light load-bearing structure fixed on the external wall and spaced from it to create a suitable cavity for containing plant ducts. The purpose of the present work is to evaluate, through dynamic simulation, the energy performance of a building renovated with the I-BEST system.

x Window operation in naturally ventilated classrooms is the only strategy for achieving proper air change rates. The modeling of the ventilation rate based on the window state implies knowledge of the window opening angle to evaluate the net exchange area. Nonetheless, the sensors most used to monitor window opening state are contact sensors, which allow only a binary state (i.e., open/close) to be devised. This work aims to investigate the effect that window opening information has on ventilation rates and building performance simulation by comparing the case in which window opening is described by the opening angle to the condition in which it is described as a binary I/O variable. A measurement campaign was conducted on six classrooms in a secondary school in Morlupo, Rome. Temperature, CO2 concentration and relative humidity were monitored in the six classes, while temperature and relative humidity were monitored outdoors. During school time, a few students per class were asked to report information concerning the number of occupants and the opening state of windows and shutters on a discrete scale. From the data collected, an equivalent opening area was calculated, accounting for the combined opening of windows and shutters, being therefore representative of the net exchange area. Based on the original dataset, a second dataset was generated by considering binary window opening information both for windows and shutters. The two datasets were used, together with environmental data, to train behavioral models that were then fed into a building energy simulation model. The results of the simulations show that the simplified dataset causes an overestimation of the air changes and of the building energy need.

x Numerical simulations are widely used to evaluate the thermal comfort and energy savings in the retrofit of historic buildings. In most cases, however, no detailed data are available on the materials and stratigraphy of the building envelopes, and on-site measurements can be expensive and time consuming. The present work uses as a case study a university building characterized by a high thermal capacity in the city of Rome to verify whether the use of natural ventilation can be a practice of use in order to guarantee energy saving and natural comfort. To this end, in the summer of 2020, an experimental campaign was carried out aimed at acquiring thermofluximetric measurements through the vertical walls, the air temperature inside and outside the analyzed environment and the air velocity. Measurements were conducted under three different usage protocols, including night ventilation and 24-hour continuous ventilation. These measurements made it possible to identify the thermophysical characteristics of a wall considered "equivalent" to the real wall, allowing the realization of thermofluidodynamic computational models. In particular, in the study, 3 different stratigraphies were considered and compared, corresponding in the first case to the equivalent wall, in the second to that available from the Comsol software library, and, finally, in the third and last case, from literature data (Tabula project) for the building typology analyzed. From the analysis, it emerged that the 3 groups of parameters do not have a significant impact in terms of variation of internal comfort, confirming the reliability of the use of the literature values for these types of modeling.

x Building simulations play a fundamental role both in applications like the design of new constructions and the optimization of building operation and control. This is quite relevant in the current energy framework, in which the energy consumption of buildings has increased over past decades. The reliability of the results’ model does not depend only on the model itself, like the mathematical expression or the resolution process, but it is also related to the uncertainty that those parameters involve. This can cause discrepancies between the simulated and the real behavior of the building, causing a deviation from the expected one of the performance of a building. Hence, the calibration procedure of the model is a necessary process which allows more accurate results to be obtained and predictions that are closer to the real behavior of the building to be made, minimizing the discrepancy between predicted and actual performance by changing the values of the simulation parameters. When it comes to calibration of simulation models, many approaches are available in the literature, comprising manual and iterative ones, graphic comparative procedures, techniques based on specific tests, and many others. Among all possible approaches, optimization-based calibration is the most widely adopted in model calibration. However, this approach, which is usually based on evolutionary algorithms, has the disadvantage that it requires many expensive simulations to be run, especially when the number of parameters to be calibrated is high. This issue can be overcome by a preliminary sensitivity analysis that reduces the number of parameters to be calibrated and by an efficient optimization algorithm. For this reason, this work proposes a framework based on a sensitivity analysis designed to identify the most significant parameters separately on the energy budgets and other monitored environmental variables. The proposed calibration procedure is based on functional approximation models, which greatly increases the efficiency of the optimization algorithm. The case study is a university library placed in the municipality of Trento, Italy. The building was monitored in terms of indoor carbon dioxide, indoor temperature, and relative humidity. Results show how successful the proposed approach is in reducing the computational time required for calibration, especially when considering models with a high degree of complexity.

x Air-to-water heat pumps are one of the most promising and increasingly widespread solutions, despite some intrinsic drawbacks, such as their poor efficiency at low ambient temperatures and at high sink temperatures, e.g., in domestic hot water production. In this context, hybrid heat pump systems combining air-to-water heat pumps and boilers (HSs) have been proposed on the market, especially for the renovation of existing buildings, where high supply water temperatures are typically required. Even though HSs are off-the-shelf technology, the topic has recently gained interest in research. HSs consist of two generators, which must be designed with an integrated approach from the start. However, the performance improvement hinges on the availability of a detailed model able to accurately predict the HS performance. Most of the studies available in the literature use models based on performance maps that are not suitable for HS design. This study presents a new detailed model of a hybrid system, developed in the MATLAB environment. The model adopts a quasi-physical representation of the heat pump cycle and condensing boiler. The boiler model thermodynamically simulates the combustion process, using the Cantera solver and the Gri-Mech properties. The heat pump model simulates the thermodynamic cycle, using refrigerant properties obtained from Cool-Prop libraries. A detailed model for each main component of the system is developed. Component models are combined, thus allowing the user to consider the influence of single components or construction parameters on the over-all HS performance. Individual component models were validated against software or performance data provided by manufacturers. The validation proved that the models of the single components can reproduce performance with high accuracy. Therefore, the model can be used for future studies involving HS design, to analyze the influence of construction choices on overall system efficiency.

x The spread of COVID-19 has significantly increased attention focused on the air quality of indoor environments. All major international health organizations (e.g., World Health Organization, etc.) recognize the importance of ventilation in enclosed spaces in reducing pathogen concentrations and fighting the Corona virus, or future pandemics. In this context, the roadmap to ensure safer and healthier indoor environments, by also guaranteeing an adequate comfort level, involves the implementation of several measures leading to a not-negligible increase in buildings’ energy consumption. Within this framework, the present paper aims to analyze the adequacy of the current Indoor Air Quality (IAQ) standards requirements, and to assess the impact of IAQ improving measures on end-use energy profiles to ensure occupants’ comfort. Specifically, a dynamic simulation approach is adopted to estimate, for each building space typology defined by ASHRAE 62.1, both air contaminant concentration and zone energy consumption. Specifically, the risk to occupants of contracting the COVID-19 virus was assessed for different scenarios using a modified Wells-Riley model. The study confirms the urgent need for enhancing ventilation in enclosed spaces to exit the health emergency caused by COVID-19. In addition, the paper provides quantitative data on the resulting operating costs of HVAC systems.

x The smart built environment (SBE) exhibits a dynamic integration between the physical and digital environment, where the physical elements, such as spaces, walls, windows, doors, roof, and floor, interact with the digital sensing elements, such as sensors, actuators, control systems, and networking systems. Energy neutrality is a concept dealing with the lifecycle energy performance of energy-saving sensing devices integrated into the SBE, such as the smart sensor-actuator system (SSAS). Ontology is a concept of representing and organising information (and their inter-relationships) about a specific domain with the intention of managing complexity, enhancing understanding, and promoting problem-solving skills. Employing semantic web technologies, a framework for designing and simulating energy-neutral, sensor-embedded smart buildings is proposed, which exhibits an ontological integration of Lifecycle Assessment (LCA), Building Information Modelling (BIM), and Product Lifecycle Management (PLM). A preliminary implementation of the proposed framework is demonstrated using OWL (Ontological Web Language) in Protégé software. After that, a design interaction matrix between buildings (and their components), building designers, product designers, and lifecycle practitioners is developed to provide efficiency, optimisation, and sustainability in the design process. This integration framework would streamline the design process, providing a collaborative simulation platform for cross-field designers to enhance the environmental performance of the SBE. In the future, this framework could be employed to create a robust real-time integrated IoT-based platform for designing and modelling energy-neutral smart buildings.

x Urban Building Energy Modeling and Multi-Objective Optimization are two very computationally intensive applications of Building Performance Simulation. In this research, a simplification algorithm developed to speed up thermal simulations at urban scale was tested to assess its performance in optimization studies. Since the algorithm showed good accuracy at the individual building level, it was applied to standalone buildings, considering a set of energy efficiency measures and all the possible combinations of four objectives, i.e., heating and cooling needs, thermal comfort and costs. The algorithm showed adequate performance in finding the optima with the same inputs for most of the considered buildings and combinations of objectives in different climatic conditions, allowing the simulation time to be reduced to one third.

x To reduce greenhouse gases emissions related to the building sector and to make informed decisions about sustainable building design and urban planning, building energy simulation should be adopted as a supporting tool by designers and policy makers. However, since building simulation is extremely time-consuming, its application is limited in daily design work. This research aims at testing a new simplification algorithm proposed for Urban Building Energy Modeling to reduce the computational complexity of thermal models in favor of the simulation speed without compromising accuracy. The procedure was applied on two educational buildings of complex shapes located in Bolzano, Italy. Results show that the simplified models reduced the simulation time up to 135 times, with building level relative annual deviations lower than 6 %.

x Cross-Laminated Timber (CLT) is a building technology that is becoming increasingly popular due to its sustainability and availability. Nevertheless, CLT structures present some challenges, especially in terms of both structure-borne and airborne insulation. In this paper, a 200 -mm CLT floor was characterized in the laboratory, according to ISO standards, by using a standard tapping machine in order to understand its vibro-acoustic behavior in terms of radiation efficiency for structural excitation. In particular, experimental tests were compared to analytical prediction models available in the literature to check the accuracy of simulation methods in the prediction of the radiation capability of CLT structures.

x In this research, a probabilistic model was applied to a building model of a public building located in Bolzano, Italy, for the assessment of the airborne contagion risk due to Covid-19. Different ventilation strategies were investigated in terms of risk reduction, as well as the effectiveness of the Pfizer vaccine. TRNSYS and TRNFLOW models of the public building were created to evaluate the internal airflows, necessary to calculate Covid-19 concentrations in the offices. Both building and airflow models were calibrated against measurement data collected with temperature sensors located in some of the building offices and hallways, prior to coupling with a Monte Carlo model for the risk assessment process. The results were reported in terms of infection risk, both for occupants located in the same office, as well as for occupants in adjacent spaces. It was observed that the current operational modes of both natural and mechanical ventilation are able to limit the spread of Covid-19 only in case of vaccination coverage presence and if the Delta variant is considered. If vaccination coverage is not present or if the Omicron variant is concerned, a higher frequency of windows opening, and a schedule based on occupancy profiles for mechanical ventilation should be adopted.

x Poor Indoor Environmental Quality IEQ conditions, defined by the four environmental comfort domains (thermo-hygrometric, visual, Indoor Air Quality IAQ and acoustic), can cause not only discomfort to building occupants, but also lack of concentration, and harmful and unhealthy status. In this work, visual, thermal and IAQ conditions in a primary school located in Bolzano, Italy, were analysed to assess their impact on students’ learning performance. After a survey in the school, which included measurements of illuminance, luminance, optical properties of materials, air temperature and CO2 concentration, some simulation models were developed. Through a Radiance model, daylight metrics (e.g., Daylight Factor and Daylight Autonomy) and glare metrics (e.g., Daylight Glare Index and Daylight Glare Probability) were calculated. Furthermore, the melanopic illuminance was simulated to evaluate the non-visual effects of light on children’s circadian cycles. In addition to that, EnergyPlus simulations allowed an evaluation of the long-term indoor air quality and thermal comfort conditions, which were used to estimate the students’ potential performance loss according to some models in the literature. Interventions on shading devices and HVAC system controls were suggested, in order to optimize IEQ, with a minimization of performance loss and energy consumption.

x In the last few decades, European countries have been facing an increasing demand for active air-conditioning (cooling and dehumidification) in the summer period. As a good alternative to energy demanding vapor compression cooling-based air dehumidification, building HVAC systems integrating desiccant-based dehumidification has drawn increasing attention. These technologies offer the possibility to significantly reduce the energy requirement for air dehumidification and post-heating due to excessive cooling. In fact, air-conditioning systems that use solid or liquid desiccant offer the interesting capacity of separating dehumidification and sensible cooling of air and realizing high-energy-efficiency systems. However, the complexity perceived by technicians towards the design of air-conditioning systems based on these technologies actually limits their adoption in HVAC systems, mainly due to the difficulties in predicting the performance of the desiccant devices, which is the crucial component of the system. On the one hand, many simplified approaches commonly adopted to simulate and optimize the dehumidification performance are based on steady-state models and their reliability under unsteady conditions is questionable; on the other hand, accurate detailed models available for the design and development of components do not turn out to be particularly suitable for simulation of energy systems, due to their high computational cost. The present work focuses on desiccant wheels, whose performance is not only directly related to the properties of the sorption material, but also depends strongly on operating conditions, such as rotational speed, regeneration temperature and inlet air conditions, which are typically non-stationary in real application. In this context, the purpose of this paper is to assess the reliability of a simplified model to predict the behavior of a desiccant wheel under dynamic conditions. To do so, a detailed model of a desiccant wheel is developed and validated against experimental data available in the literature. Finally, a comparison between the developed detailed model and the simplified model under dynamic conditions is carried out.

x The visualization of building energy data is an open topic, intuitive approaches are rare and new concepts are required to handle big data collected by more and more sensors or even derived from energy simulation results. The interpretation of data, either derived from a monitoring system or from building simulation analysis, can be difficult to handle. Combining geometrical data and energy data into a visualization interface could be a promising way to help designers and facility managers to better understand the use of different spaces, enabling a higher efficiency of building management. In this paper, an application for visualizing monitoring data or simulation results by means of Mixed Reality and BIM is presented. For the purpose, a doll’s house concept (third-person observer) has been adopted as a container for the visualization of energy data in a geometrical context. Time-series based interactive diagrams, derived from monitoring system or simulation results, are integrated into geometrical holograms of buildings or parts of buildings (like floors) and they allow intuitive working. Moreover, multi-user scenarios applying cloud anchors are supported. The geometrical models are retrieved by applying Building Information Modelling (BIM).

x We can mainly identify two groups of models in the literature to calculate solar irradiance incident on building envelope surfaces: horizontal diffuse irradiance models, to distinguish beam and diffuse horizontal components and irradiance models for tilted surfaces, to determine the irradiance incident on inclined surfaces. Due to the fact that solar irradiance data are different depending on location, climatic condition and topographic factors, there is no uniform solar irradiance model that can provide the same level of accuracy worldwide. Furthermore, this is even more critical in mountain areas, characterized by terrain complexity and the presence of specific local climatic conditions affecting solar radiation distribution. In this research, the performance of 22 horizontal diffuse irradiance models and 12 irradiance models for tilted surfaces was assessed to check their suitability for application in mountain regions. The analysis was carried out in the Italian Alps, specifically, in the city of Bolzano, using as a reference the global solar irradiance data collected for both horizontal and vertical surfaces. Moreover, the energy needs for space heating and cooling of 48 simplified building configurations were simulated to quantify the impact of solar irradiance models on the simulated building energy performance.

x The European goal of decarbonization drives design toward high-performance buildings that maximize the use of renewable sources. Hence, the European RED II Di-rective (EU, 2018) and the Italian decree (DL 8/11/2021) raise the minimum renewable share in new buildings and major renovations. In this framework, an air-source heat pump (ASHP) combined with an on-site photovoltaic system (PV) is one of the most popular solutions. However, the effectiveness of this heating system in mountainous contexts is not taken for granted, since the harsh climate induces both an increase in heating requirements and a deterioration of heat pump performance. For these reasons, energy simulation is a useful tool for understanding energy behavior and evaluate strategies to ensure the best energy savings. Currently, the renewable quota verification involves a quasi-steady state calculation on a monthly basis. However, this implies the use of the national grid as a battery through the net metering mechanism. The actual share of renewable coverage in the absence of expensive electric storage will necessarily be lower. This work analyzes the actual renewable share achievable in a new building in a mountainous area. Five representative locations in the province of Trento were initially identified through a cluster analysis. The renewable share was evaluated through a coupled dynamic simulation of the building and the energy systems. The results show how the calculated renewable share in this building changes according to the time interval used to close the balance with the grid. The evaluation of the renewable quota (QR) was carried out not only closing the balance by the hour or sub-hour but also by the month.

x Experiential Learning (ExL) has long been considered a useful and necessary tool in educational courses in several different fields, including engineering. Nevertheless, traditional didactical approaches have prevailed, in particular, in Bachelor and Master Engineering programs, at least in Italy. This implies the focus is kept more on theoretical aspects even for disciplines in which practical activities and learning by doing could provide the necessary competence for students to enter the job market promptly. Futhermore, ExL is recognized as providing a more immersive educational environment, capable of increasing participation and motivation in students. One of the techniques introduced by the ExL consists of roleplaygames, some of which in the form of business games. This work reports about the main outcomes from an initial implementation of a business game-like approach to train perspective building envelope and energy systems designers. In particular, the game is intended to train students in the use of building simulation, showing what the potential and the peculiarities of the job can be when approaching the market. In addition, since it is commonly recognized that, while BPS is widely used in teaching and research, it is not widespread among practitioners, the game was also conceived to promote BPS use in practice. The main features, including constraints and critical points, of the implementations within a university course in an Energy Engineering study program are described together with some suggestions for future improvements.