Carla Balocco

A non-dimensional analysis of a ventilated double façade energy performance

A method based on dimensional analysis is proposed for a natural ventilated double facade energy performance study. The 14 non-dimensional numbers defined, with physical meaning, can be used to describe thermal and energy performance of different facade designs. A comparison between non-dimensional numbers solved by simulation, experimental data, and the obtained and validated correlation results is reported. A simple tool to evaluate thermal performance of a solar chimney is provided. Applying it, useful design indications can be derived also by varying simple parameters using thermal and physical data easy to get.

Thermodynamic parameters for energy sustainability of urban areas

This paper presents some thermodynamic indicators useful for energy planning of urban areas, and for defining the scenarios of integrated low environmental impact energy strategies and actions in an urban area. It is based on the results of the energy balance of a reference volume obtained by the Geographical Information System (GIS) techniques applied to the built-up area studied. The defined parameters allow evaluation of the sustainability of energy use in an urban area and its areal distribution in different building meshes superimposed on the area considered, using entropy.

Hospital ventilation simulation for the study of potential exposure to contaminants

Airflow and ventilation are particularly important in healthcare rooms for controlling thermo-hygrometric conditions, providing anaesthetic gas removal, diluting airborne bacterial contamination and minimizing bacteria transfer airborne. An actual hospitalization room was the investigate case study. Transient simulations with computational fluid dynamics (CFD), based on the finite element method (FEM) were performed to investigate the efficiency of the existing heating, ventilation and air-conditioning (HVAC) plant with a variable air volume (VAV) primary air system. Solid modelling of the room, taking into account thermo-physical properties of building materials, architectural features (e.g., window and wall orientation) and furnishing (e.g., beds, tables and lamps) arrangement of the room, inlet turbulence high induction air diffuser, the return air diffusers and two patients lying on two parallel beds was carried out. Multiphysics modelling was used: a thermo-fluidynamic model (convection-conduction and incompressible Navier-Stokes) was combined with a convection-diffusion model. Three 3D models were elaborated considering different conditions/events of the patients (i.e., the first was considered coughing and/or the second breathing). A particle tracing and diffusion model, connected to cough events, was developed to simulate the dispersal of bacteria-carrying droplets in the isolation room equipped with the existing ventilation system. An analysis of the region of droplet fallout and the dilution time of bacteria diffusion of coughed gas in the isolation room was performed. The analysis of transient simulation results concerning particle path and distance, and then particle tracing combined with their concentration, provided evidence of the formation of zones that should be checked by microclimatic and contaminant control. The present study highlights the fact that the CFD-FEM application is useful for understanding the efficiency, adequacy and reliability of the ventilation system, but also provides important suggestions for controlling air quality, patients’ comfort and energy consumption in a hospital.

A multidisciplinary approach to the study of cultural heritage environments: Experience at the Palatina Library in Parma.

The aim of this paper is to describe a multidisciplinary approach including biological and particle monitoring, and microclimate analysis associated with the application of the Computational Fluid Dynamic (CFD). This approach was applied at the Palatina historical library in Parma. Monitoring was performed both in July and in December, in the absence of visitors and operators. Air microbial monitoring was performed with active and passive methods. Airborne particles with a diameter of ≥0.3, ≥0.5, ≥1 and ≥5 μm/m3, were counted by a laser particle counter. The surface contamination of shelves and manuscripts was assessed with nitrocellulose membranes. A spore trap sampler was used to identify both viable and non-viable fungal spores by optical microscope. Microbiological contaminants were analyzed through cultural and molecular biology techniques. Microclimatic parameters were also recorded. An infrared thermal camera provided information on the surface temperature of the different building materials, objects and components. Transient simulation models, for coupled heat and mass-moisture transfer, taking into account archivist and general public movements, combined with the related sensible and latent heat released into the environment, were carried out applying the CFD-FE (Finite Elements) method. Simulations of particle tracing were carried out. A wide variability in environmental microbial contamination, both for air and surfaces, was observed. Cladosporium spp., Alternaria spp., Aspergillus spp., and Penicillium spp. were the most frequently found microfungi. Bacteria such as Streptomyces spp., Bacillus spp., Sphingomonas spp., and Pseudoclavibacter as well as unculturable colonies were characterized by molecular investigation. CFD simulation results obtained were consistent with the experimental data on microclimatic conditions. The tracing and distribution of particles showed the different slice planes of diffusion mostly influenced by the convective airflow. This interdisciplinary research represents a contribution towards the definition of standardized methods for assessing the biological and microclimatic quality of indoor cultural heritage environments.

Measuring thermal properties with the parallel wire method: a comparison of mathematical models

The accuracy of thermal conductivity and diffusivity measurements using the parallel wire method depends on the mathematical model used. This work presents an analytical solution of a model that takes into account the probe radius and the thermal contact resistance between the material and the probe. The model is compared to the classical hot wire model on the basis of the acquired experimental data.

Experimental and Numerical Investigation on Airflow and Climate in a Real Operating Theatre under Effective Use Conditions

Abstract In the present study microclimate and airflow patterns in a real operating theatre (OT) under effective use conditions are investigated. Surgical staff movements and sliding door opening/closing effects on the air thermal distribution and velocity fields are considered. Experimental measurements and numerical simulations are carried out for the “at rest” and “operational” conditions of the OT. Two “operational” use conditions are considered: “correct” and “incorrect” during a simulated hip surgery. Numerical and experimental results comparisons are used to check their compliance with the standard limits. Results mainly show the ventilation system effectiveness in providing the expected conditions, even though local perturbations due to operational conditions are clearly pointed out.

Shannon entropy for energy technologies ex-ante evaluation

Most of the international literature has used Shannon entropy to measure the information gap. In this paper we propose a method that uses Shannon entropy to evaluate ex-ante energy technologies in a decision making process. It was called ITEM, i.e., Information Theory Energy technology ex-ante evaluation Method. The aim was to have a suitable tool for characterising the most critical project during energy planning. The ITEM method was used to evaluate ex-ante two renewable energy scenarios: biomass energy production vs. bio fuel gasoline production. Analysis results highlight bio fuel low entropy, promoting this technology scenario from every point of view.

Light, Information and Perception inside Historical Buildings. A Case Study

Many literature studies demonstrated that technologies belonging to cognitive neuroscience can be used in museums. Physics, optics, thermodynamics and neurosciences applications can provide an important support to applied and practical research for lighting our Cultural Heritage. In our research we provided a multidisciplinary integrated approach for the study of the luminous climate inside a historical building: Villa La Quiete in Florence is the case study. The quantitative measurements of the relationship between observer and artworks were performed, with eye-tracking technique application. The Information Theory, read on a thermodynamic basis, the ergonomy of the multi-perceptive learning and optical physics, were the fundamental tools for the assessment of the correct light sources in terms of spectral emission and colour light temperature. The eye-tracking technique combined with the results of lighting parameter quantification, allowed checking how the colour of light changes the observers perception, and from the information theory point of view, the communication and interpretation process of the signals due to different lighting. At the same time, it was also possible to measure by assessing the perceptive data of the visual path, and thus the neg-entropy, the informative content of the interaction of light with works of art.

Assessment of the luminous climate inside Historical Buildings. Experimental measurements and lighting simulation of the Hall of five hundred in Florence

An investigation for a new lighting solution of an important historical Hall, based on proposed experimental methodology and simulation models is presented. The suggested approach can be a useful example of non-invasive experimental measurement processes and lighting solutions in the field of Cultural Heritage.