Fabio Bisegna

Climate models for the assessment of office buildings energy performance

Abstract In the last few years many advanced computer packages, characterised by a considerable integration between thermal and visual aspects, were developed to support designers and to study building energy performance, innovative materials and daylight control strategies and systems. These packages, as a function of their complexity and final use, require different types of outdoor data, ranging from monthly (MTD) or seasonal typical days (STD) to more complex typical meteorological years (TMY). Both the deterministic and the stochastic components of outdoor data are present in TMYs, while MTDs and STDs take into account only the deterministic component. The use of MTDs or STDs produces a sensible reduction of the calculation time, above all appreciable in the first phase of the building design process, although it introduces an element of uncertainty in simulation results due to the absence of the stochastic component of outdoor data. This uncertainty is not easily predictable, as reported by many authors. The aim of the present work is to investigate the influence of the stochastic component of meteorological data in evaluating office building energy performance in Mediterranean climate. The study is performed by an advanced numerical computer package, Integrated ENergy Use Simulation (IENUS), which can process different types of climatic data. Different typologies, systems and space managements are investigated.

A territorial based strategy for the distribution of sensor networks in smart cities

Nowadays land governance has to keep up with sudden environmental and social transformations of cities. Therefore it is necessary to improve the exchange of real-time information among different stakeholders. One of the solutions is to acquire data not only by Remote Sensing, but also by sensor networks distributed on the territory. In this way information are developed with multiple connections and a smarter management of cities can be achieved. However there are not strategies for the distribution of the sensors yet and it often takes to an excess of not interrelated data. Therefore it is important to design the networks according to the features of the territory in which they are distributed. This aim can be achieved with the study of infrastructural, cultural and functional aspects of the cities. The goal of this paper is to define a method to plan an optimized distribution of sensors in the city based on the analysis of characteristics and relations among urban zones.

Home smart grid device for energy saves and failure monitoring

The growing sensibility on energy consumption has focused people interest in energy optimization technologies. Non-intrusive load monitoring system (NILMS) are a cheap solution that require minimal equipment and installation time. The aim of the research is to develop a load analyzing platform for electrical devices to obtain information on their functionality and to display the costumer advantage to change their energy class. It monitors malfunctions or non-critical failures in real-time. It also counts the device operative life-time. The architecture is made of a local analysis electrical plug, which get the load information, and a central unit which elaborates data. The hardware implements a hall-effect ammeter, a power transformer and a micro controller (AT-mega328). The central unit is a small integrated computer (Raspberry). The communication between the devices utilize a low-range radio transmitter.

Meteorological days for HVAC system design in Mediterranean climate

Abstract In this paper several real days belonging to a Typical Meteorological Year (TMY) are proposed as design days for HVAC systems in summer conditions. A parameter, the equivalent temperature, that is a different combination of related values of hourly solar radiation, wet and dry bulb temperature, is defined. Real days with maximum values of these parameters are selected as Design Meteorological Days (DMDs) to evaluate summer cooling load. Results are analysed in terms of energetic performances of the system to identify the most suitable DMDs to be used in the design process. The DMD selection is based on the criterion of reducing HVAC part-load working periods and on the risk level to alter indoor design conditions. The approach uses the computer package Integrated ENergy Use Simulation (IENUS), specifically developed for the Mediterranean climate, to characterise both energetic and environmental aspects. Simulations are referred to a non-residential building designed on the base of an energy saving criteria. Typical Meteorological Years are used both as meteorological data inputs as far as data base to select DMDs.

A step towards the optimization of the indoor luminous environment by genetic algorithms

Buildings are heavily responsible for energy consumption and CO2 emissions. Increasing their energy efficiency is in the direction of the EU strategies; and this is consistent with EU Energy Performance of Buildings Directive (EPBD 2010/31/EU), 2010. In this view the design and management of daylight and artificial light can play a fundamental role. In this paper, a method to optimize indoor lighting design from energy efficiency, economic and environmental viewpoints is presented. The optimization was developed through the Genetic Algorithms technique and the optimal layout in terms of number, location and mounting heights of luminaires in a generic office room was evaluated. Solutions with different types of light sources, nominal luminous flux and photometric distribution curves were compared and the cost effectiveness of these alternatives was also considered. The systems resulting from the optimization show increased uniformity of illuminance, a reduction of the number of luminaires and a decrease of the maximum UGR values, proving the effectiveness of the technique in the lighting design field. Results show that current methods for lighting design can still be improved to achieve optimal configurations in terms of energy efficiency and cost effectiveness.

A roadmap toward the development of Sapienza Smart Campus

University campuses are comparable to cities, despite the differences in dimension and kind of structures. The Smart City model can be scaled and adapted to them in order to create a Smart Campus. In this framework the research project SC2 is based on an integrated Smart planning in order to reach this goal. The strength of the project is its methodological approach characterized by 5 key points: planning, integration and collaboration, flexibility and scalability. SC2 is the starting point to transform universities and single urban elements using a framework which can be extended and scaled to different urban contexts.

Outdoor work and solar radiation exposure: Evaluation method for epidemiological studies

BACKGROUND The health risk related to an excessive exposure to solar radiation (SR) is well known. The Sun represents the main exposure source for all the frequency bands of optical radiation, that is the part of the electromagnetic spectrum ranging between 100 nm and 1 mm, including infrared (IR), ultraviolet (UV) and visible radiation. According to recent studies, outdoor workers have a relevant exposure to SR but few studies available in scientific literature have attempted to retrace a detailed history of individual exposure. MATERIAL AND METHODS We propose a new method for the evaluation of SR cumulative exposure both during work and leisure time, integrating subjective and objective data. The former is collected by means of an interviewer administrated questionnaire. The latter is available through the Internet databases for many geographical regions and through individual exposure measurements. The data is integrated into a mathematical algorithm, in order to obtain an esteem of the individual total amount of SR the subjects have been exposed to during their lives. RESULTS The questionnaire has been tested for 58 voluntary subjects. Environmental exposure data through online databases has been collected for 3 different places in Italy in 2012. Individual exposure by electronic UV dosimeter has been measured in 6 fishermen. A mathematical algorithm integrating subjective and objective data has been elaborated. CONCLUSIONS The method proposed may be used in epidemiological studies to evaluate specific correlations with biological effects of SR and to weigh the role of the personal and environmental factors that may increase or reduce SR exposure. Med Pr 2016;67(5):577-587.

Evaluation of historical museum interior lighting system using fully immersive virtual luminous environment

Saint Rocco Museum, a historical building in Venice, Italy is used as a case study to explore the performance of its’ lighting system and visible light impact on viewing the large size art works. The transition from threedimensional architectural rendering to the three-dimensional virtual luminance mapping and visualization within a virtual environment is described as an integrated optical method for its application toward preservation of the cultural heritage of the space. Lighting simulation programs represent color as RGB triplets in a devicedependent color space such as ITU-R BT709. Prerequisite for this is a 3D-model which can be created within this computer aided virtual environment. The onsite measured surface luminance, chromaticity and spectral data were used as input to an established real-time indirect illumination and a physically based algorithms to produce the best approximation for RGB to be used as an input to generate the image of the objects. Conversion of RGB to and from spectra has been a major undertaking in order to match the infinite number of spectra to create the same colors that were defined by RGB in the program. The ability to simulate light intensity, candle power and spectral power distributions provide opportunity to examine the impact of color inter-reflections on historical paintings. VR offers an effective technique to quantify the visible light impact on human visual performance under precisely controlled representation of light spectrum that could be experienced in 3D format in a virtual environment as well as historical visual archives. The system can easily be expanded to include other measurements and stimuli.

Research perspectives of the influence of lighting modes on changes of human functional state by means of “smart lighting”

In studies of non-visual lighting effects conflicting results are frequently obtained. We suppose that such individual differences can be related to the initial functional state, as well as to the individual type of response to light exposure. This raises the question of the need to develop methods for express-diagnosis of functional state in response to a standardized light exposure. Our results show that the effect of fatigue during mental workload can be detected by measuring the critical flicker fusion frequency for light with the specific colors and brightness levels. However, the reliability of this method is difficult to estimate because of the different brightness of LEDs of different colors. We believe that the using of a “smart lighting” devices, allowing obtaining specific color and brightness by mixing individual colored LEDs, will overcome this limitation.

Lighting distribution affects pedestrians' sense of security

The greatest obstacle to a pedestrians Sense of Security (SoS) is lack of lighting. This research analyzes lighting characteristics which affect a pedestrians SoS, including how lighting distribution changes perception, to design lighting for night-time walking that maximizes the SoS without increasing energy consumption.