Computational Fluid Dynamic Study with Comfort Analysis in Large Atrium of the Angelo Hospital in Venice

To improve the thermal comfort in the hall of the Angelo Hospital (Venezia) an analysis was developed by using Computation Fluid Dynamics and considering some configurations for the air-conditioning system and for the solar shading devices. The reference configuration consists of the installation of four fan coils in the area coupled with a 3 m high metal casing used for solar shading. Then, three other solutions are proposed: by increasing the number of fan coils and changing their position, by adding some radiant panels arranged on the walls, and by inserting a physical confinement as a lateral confinement. The study consists of three sections. Firstly, a section in which the study area is modelled through a strong simplification that allows to represent only a slice of the domain but to immediately evaluate the role of the casing. A second section in which the area is completely modelled, and a third section in which a comfort evaluation is carried out. The analysis shows that the metal casing brings a substantial benefit due to the solar shielding it causes. The radiant panels cool the area only near the wall. The increasing of the number of the fans leads to an excessively high air speed and localized discomfort due to drafts. The lateral confinement on the north and south side is the one that guarantees better cooling of the study area

Assessment of the IEQ in Two High Schools by Means of Monitoring, Surveys and Dynamic Simulation

Abstract This work presents an assessment of schools' indoor environmental quality, based on investigations carried out in three Italian classrooms in Treviso, in the North-East of Italy. A first monitoring campaign was performed during the mid season (May-June), a second one during the heating period (January-February). At a first stage, the study was focused on two different approaches, an objective and a subjective one, in order to compare the objective responses with the occupants' subjective sensations. The first method consisted of physical observations and field measurements of thermal environmental parameters, used to calculate Fanger's comfort indices and to apply a comfort adaptive model. The subjective approach was managed by giving students and teachers a survey about their personal judgment concerning the level of comfort perceived. Finally, a simulation model has been built-up and calibrated using the indoor values of air temperature and air humidity trends collected by data loggers. A generic optimization program has been used to calibrate the thermal model. The responses from measurements, surveys and simulations were integrated, analyzed and compared, obtaining a good agreement between the three approaches in assessing the classroom thermal comfort category

Energy Performance And Long-Term Evaluation Of Internal Thermal Comfort Of An Office Building With Different Kinds Of Glazing Systems And Window Sizes

Although the presence of large window surfaces could be preferable during the heating season when solar gains through the glazed components can overcome heating losses from the same surfaces, during the cooling season more attention has to be paid in order to limit the inlet of solar radiation which causes the increment of cooling load. Generally the optimal tradeoff for energy optimization, as already underlined in a previous paper by the authors, is using low thermal transmittance and high solar factor glazing, even if higher solar transmittance considerably worsens the cooling performance. However, the choice of glazing type and the design of windows on a façade may depend on comfort consideration besides energetic evaluations. Thermal sensation of an individual is mainly related to the whole thermal balance of the human body. Comfort limits can in this case be expressed by two indexes proposed by Fanger in 1970: the Predicted Mean Vote, PMV, and the correlated Predicted Percentage of Dissatisfied, PPD. The PMV depends on four environmental parameters (air temperature, air humidity, air velocity and mean radiant temperature) and two variables connected with human being (physical activity and clothing). The air temperature, the air humidity and the air velocity inside a building are directly under the system control. In contrast, the mean radiant temperature is strongly conditioned by the envelope surface temperature, and in particular, by the presence of glazed surfaces whose insulating performance is lower than the opaque components one. In this paper the study of heating and cooling energy needs of an open-space office with different windows’ characteristics has been carried out controlling the internal comfort conditions with appropriate setpoint of the system. An office module with windows on a single façade, or on opposite façades, oriented towards 3 different orientations has been simulated, varying the glazed area (2 sizes), the glazing systems (4 types) and considering three localities of central and southern Europe. The PMV have been calculated for each hour of occupation of the whole year assuming two season as regards the setpoint conditions and clothing level. Calculations have then been repeated considering also the effect of the diffuse and beam solar radiation through the windows directly reaching the occupants. The evaluation of the long-term comfort conditions (on seasonal basis) has been conducted considering some statistical indicators of distribution (the median, minimum, maximum and the interquartile range) and the energy performance of the different glazing solution have been compared accounting for the comfort one

European projects on district energy-renovations and Italian best practices

Buildings are the major source of greenhouse gas releases: lowering their energy consumption and emissions is particularly challenging for the existing building stock. This topic was examined at an individual building level in the International Energy Agency\u2019s EBC Annex 56. However, the increasing request of nearly zero energy buildings highlight another important topic: the need of an increase in energy production for satisfying the required amount of renewable energy sources. This task could be solved at the district level for the existing buildings, even if it is a complex issue. This work presents a general introduction on the topic of Urban and Regional Integrated Energy Planning, with a focus on the regional and supraregional process to create and manage energy plans. After the first introductory part, the method is explained through a description of its main phases and the tools used. The subsequent section presents a general overview on the European projects that deal with the problem of district regeneration; the ones that are more related to the topic of this work are considered in a deeper way through tangible applications in Italian cities. The study of already done examples will help in the definition of benefits and drawbacks, with the aim to defining newer and better energy planning procedures

The Rising Damp in Venetian Masonry : Preliminary Results Comparing Laboratory Tests and Dynamic Simulations

The control of moisture in the building sector represents a widespread issue and research topic, in terms of improving the quality of indoor space healthiness and energy performance. In Venice, rising damp and moisture phenomena are very diffused and difficult to solve, due to building structures and specific environmental conditions. All of the buildings and artefacts in the city are presently wall structures filled with bricks, which lean on relatively permeable soil, are exposed to an environment rich in saline aerosols, and are continuously lapped by floods and brackish water. The aim of this research was to analyze typical Venetian masonry walls affected by rising damp through the application of non-destructive methods, in order to understand and assess the behavior of construction materials in specific boundary conditions. The data given by non-destructive monitoring in mock-up masonries were compared with dynamic simulations to estimate the hygrothermal behavior and analyze the effect on different parameters, such as the physical properties of new and historical materials (i.e., density, thermal conductivity, etc.), the presence and type of plasters, and the kinds of traditional treatment applications. The evaluation of experimental data, supported by simulations provides to the literature an empirical comprehension of rising damp phenomena in real masonry toward careful heritage conservation

Evaluation of the Indoor Thermal Quality in high schools buildings: strengths and limits of different assessment methods

Recent studies have pointed out how much the indoor environmental quality in schools\u2019 classrooms is an important factor which could prevent serious adverse effects not only on the students\u2019 comfort sensation, but also on their health and learning potential. However, although standards EN ISO 7726:2001, EN ISO 7730:2005 and EN 10551:2001 give recommendations about how to practically perform objective and subjective measurements, on the evaluation of the level of comfort perceived in buildings, there is the need to define a systematic and standardized way in order to implement the comfort assessment through a methodical and uniform approach. In this work the assessment of the Indoor Thermal Quality of two classrooms in one high school located in Treviso, a town in the North-East of Italy, is presented in order to highlight the strengths and the limits of two different evaluation approaches: field monitoring, survey questionnaires. To reach the aim, two monitoring and surveys campaigns were carried out, one during the spring and one during the heating season. All the four comfort areas were investigated through the questionnaires: the thermal, the visual, the acoustic and the air quality perception.. Afterwards objective and subjective responses on thermal and visual perception have been compared

historical buildings retrofit the city hall of the city of motta di livenza tv

Abstract Issues related to energy saving, environmental sustainability and safety in case of seismic events are more and more the focus of attention of public opinion and the various actors of the construction sector. The Italian housing stock needs a strong energy adjustment, functional and seismic. The majority of buildings dating back to before the entry into force of the laws on energy saving of 1976 and first of the orders on the seismic design of 2003. The intervention on private buildings is favored by various financial systems and various facilities but to intervention on the public housing stock it is not easy. Most of the public buildings are identified as historical and therefore listed by the Superintendence of Cultural Heritage. Historical constraints, facades and fine decorations and inhomogeneity of the construction techniques and materials used make it very difficult to intervene in these buildings. The article will analyze a case study: the city hall of the municipality of Motta di Livenza (TV). This historic building, listed by the Super-intendent, has been subject to an energy audit that defines what are the best measures of energy efficiency and their economic sustainability. The search result will define which are the most cost-effective interventions to associate with the project of seismic improvement already underway. The case study is a real example of finding a balance between the need for seismic and energy intervention, constraints placed by the Superintendent, the data constraints by decorations and valuable items cannot be modified and the need for improvement of interior comfort

Functional, Energy and Seismic Retrofitting in Existing Building: An Innovative System Based on xlam Technology

In recent years significant investments were made in retrofitting of existing buildings with the aim to realize a strong functional, energy and seismic refurbishment. This is a complicated challenge: the technical and economic feasibility of intervention must be correctly defined and most of interventions are not standardized or coordinated or properly managed. Given the awarenessrelatedto environmental sustainability topics, this studyfocusedon the developmentof systems andtechnologiesbased on the useof natural and environmentally sustainable materials. The paper is focused on the xlam panel that is integrated into an existing building (outside or inside the external wall) in order to improve the static and structural tightening. The system is designed for modularization and standardization for giving simplicity and speed of assembly and low cost providing also. Through a three-dimensional and numerical model, simulations were carried out to verify and to optimize the energy behaviorof the chosenmaterials and to identifythe best combinationon thermal performancecomparedwith the costsandenvironmental impactsof the product. The valuesand the results obtainedwere testedexperimentallyin the laboratoryby the constructionof a prototype

Selection of Representative Buildings through Preliminary Cluster Analysis

Nowadays the debate in Europe concerning the energy retrofit of existing buildings is oriented to the research of the most convenient retrofit actions from a technical and economic point of view. The methodology is a cost-optimal analysis of diverse retrofit improvements, which could be conducted on a representative reference building, as happens for the definition of the new law performance requisites. Defining a reference building in a sample, implies the analysis of a large amount of information. Many data mining algorithms can be used to find correlations and patterns. One of such techniques is clustering analysis, according to which a set is divided into several homogeneous groups whose elements have similar characteristics. The aim of this work is to explore the possibility of supporting the energy audit of a large building stock using few synthetic descriptors calculated for homogeneous groups found out by means of clustering. A group of 60 schools located in the North Italian province of Treviso has been analyzed. Metered energy consumptions and seasonal degree days were available for the last five year period. Regarding the schools’ geometrical features, the gross and net heated volume, the floor area, the window area, and the dispersing envelope surface are known. Moreover the thermal resistance of the building envelope components and the type of heating system are available. Energy and geometrical indicators have been calculated: the ratio between dispersing area and gross heated volume, the window to wall ratio, the energy consumption per volume unit and the energy per volume unit and degree day. In order to cluster the schools, the sets of parameters explaining the energy performance has been determined by considering the best multiple regressions between each possible group of parameters and total energy consumption. K-means cluster analysis has then performed on the school population considering the parameters in those sets. Two are the main issues to deal with in this analyis: the type and the most suitable number of parameters to be correlated to energy consumption and the suitable number of clusters to be determined. Concerning the first aspect, all parameters have been grouped in all the possible combination from 2 to 8 elements and a multiple linear regression was calculated for each single configuration set. The more numerous the set, the more precise is expected to be the correlation, but negligible changes in the coefficient of determination was shown for more than 6 parameters which seems to be an acceptable compromise between representativeness and complexity. As regards the second issue, the regression analysis has been repeated for each cluster found, to check if the correlations between the parameters and the energy consumption improves inside each cluster with respect to the whole sample. The number of clusters is expected to improve the correlation coefficient. In the paper optimization techniques have been applied to define the parameters and the minimum number of clusters that gives the best level of correlation

An Integrated Energy and Environmental Audit Process for Historic Buildings

The valorization and sustainable management of historic centers is a topic relevant to the cultural identity and heritage of European cities. A rational strategy to preserve the centers must consider both energy and environmental retrofitting, even if this is a complex issue requiring interdisciplinary approaches, dedicated diagnostic procedures, and specific tools. Within this context, this paper proposes an integrated method for energy and environmental analysis specifically devoted to historical building retrofit. Attention is focused on cases in which building management is not interested in renovation or in a deep conservation project, but instead in green management and maintenance overhaul. The basis of the procedure is the Leadership in Energy and Environmental Design for Existing Buildings: Operations and Maintenance (LEED O+M) rating protocol. The global goal was the definition of an intervention strategy indicating the principal direction of action. The first step is identifying critical issues in the operation of the building through energy diagnosis and dynamic thermophysical simulations. The second step is defining a panel of appropriate retrofit measures. The third step is choosing between alternatives to increase the sustainability performance following an environmental assessment scheme. Ca\u2019 Rezzonico in Venice (Italy), a 17th-century palace, nowadays the seat of a museum, was used as a case study to apply the proposed methodology