146 research outputs found

    Comparison between the performances of daylight linked control system at two different latitudes

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    The aim of this work is to compare the performance of a daylight-linked control system installed and tested in two different case studies by means of a set of indices. The two case studies are characterized by different geometry, location and windows orientation. The first one is located at the ENEA premises in Lampedusa (IT, 35° 30' N); the second one is located in Palermo (IT, 38°6' N) on the third floor of the building 9 of the Department of Engineering if the University of Palermo. In both cases, the indices were calculated by using the same daylight-linked control system and the same end-use (office). The results were reported and analysed in order to demonstrate as the performances of the control system can be different from the ideal performance and that they can be different according to the installation. Furthermore, according to the first outcomes, it results that a detailed analysis of the space before the installation of the control system is a necessary practice

    Is the NZEB benchmarking approach suitable for assessing energy retrofit design?

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    Currently, many effort have been done to enable energy saving issues in building design and many definitions have been introduced for most performing constructions based on energy balance between energy demand and supply. Recently, the Net Zero Energy Building theory has bypassed old Passive House concept but many questions still remain open. Present work aims to estimate how NZEB requirements matching could be affected by the choice of their definition and the choice of weighting factor system, to be count in the energy balance. NZEB concept is mainly referred to new buildings design. Its application to existing buildings is for sure an hard task provided the architecture and physical constraints are often problematic. Nevertheless, the benchmarking approach able to assess the building performance according to the NZEB objective can be utilized for other two purposes. The first one is to assess how an existing building is far from the performances of a NZEB. The second one is to assess the contribution of a conventional retrofit in improving its energy balance

    Estimation of wind velocity over a complex terrain using the Generalized Mapping Regressor

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    Wind energy evaluation is an important goal in the conversion of energy systems to more environmentally friendly solutions. In this paper, we present a novel approach to wind speed spatial estimation on the isle of Sicily (Italy): an incremental self-organizing neural network (Generalized Mapping Regressor - GMR) is coupled with exploratory data analysis techniques in order to obtain a map of the spatial distribution of the average wind speed over the entire region. First, the topographic surface of the island was modelled using two different neural techniques and by exploiting the information extracted from a digital elevation model of the region. Then, GMR was used for automatic modelling of the terrain roughness. Afterwards, a statistical analysis of the wind data allowed for the estimation of the parameters of the Weibull wind probability distribution function. In the last sections of the paper, the expected values of the Weibull distributions were regionalized using the GMR neural networ

    Alternative energy storage options for heat pump water heater coupled with photovoltaic plant for domestic hot water production

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    The present work relies on the topic of energy storage for Heat and Electricity applied to Heat Pump Water Heaters coupled with photovoltaic plants for Domestic Hot Water production. The main idea is to evaluate the possibility to exploit the water tank as heat storage for the produced photovoltaic energy and, where appropriate combined with electrical storage. For this reason, two heat pumps with different volume size have been chosen and smart control strategies have been applied while monitoring the water temperature in the tank. Calculations account on tapping profile inferred from monitored data of a representative end-user in a Mediterranean small island. Results show how the combination of smart control strategies and battery systems is the most suitable solution in order to fulfil the domestic hot water energy demand by renewable sources while maintaining comfort requirements

    Improvement of energy efficiency and quality of street lighting in South Italy as an action of Sustainable Energy Action Plans. The case study of Comiso (RG).

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    Existing street lighting systems in most of Sicilian cities are often inappropriate due to the obsolescence of light sources and luminaires and of unsuitable light control systems unable to provide efficient on-off and dimming strategies. Improvement of energy efficiency in street lighting systems can be one of the key actions adopted by Public Administration in developing Sustainable Energy Action Plan in the framework of the “Covenant of Majors” activities. As a task of FACTOR 20 project a set of planning options have been analysed and proposed for Sicilian cities. Particularly, street lighting efficiency projects have been studied for representative case studies. A detailed survey of the public lighting systems in the city of Comiso (RG) allowed to know and represents current and design performance figures such us installed power, luminance and illuminance levels in roads categories, electricity consumption, switching and dimming schedules. To do this many lighting simulations have been performed. Several scenarios have been proposed. The results obtained show that high improvements of the lighting quality are foreseeable together with large energy and economic saving. The proposed methodological approach can be applied in most of Sicilian and South Italy cities

    Road Thermal Collector for Building Heating in South Europe: Numerical Modeling and Design of an Experimental Set-Up

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    The combination/integration of renewable energy and storage systems appears to have significant potential, achieving high-energy results with lower costs and emissions. One way to cover the thermal needs of a building is through solar energy and its seasonal storage in the ground. The SMARTEP project aims to create an experimental area that provides for the construction of a road solar thermal collector directly connected to a seasonal low-temperature geothermal storage with vertical boreholes. The storage can be connected to a ground-to-water heat pump for building acclimatization. This system will meet the requirements of visual impact and reduction of the occupied area. Nevertheless, several constraints related to the radiative properties of the surfaces and the lack of proper thermal insulation have to be addressed. The project includes the study of several configurations and suitable materials, the set-up of a dynamic simulation model and the construction of a small-scale road thermal collector. These phases allowed for an experimental area to be built. Thanks to careful investigation in the field, it will be possible to identify the characteristics and the best operation strategy to maximize the energy management of the whole system in the Mediterranean area

    Analysis of the urban heat island effects on building energy consumption

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    Urban areas usually experience higher temperatures when compared to their rural surroundings. Several studies underlined that specific urban conditions are strictly connected with the Urban heat island (UHI) phenomenon, which consists in the environmental overheating related to anthropic activities. As a matter of fact, urban areas, characterized by massive constructions that reduce local vegetation coverage, are subject to the absorption of a great amount of solar radiation (short wave) which is only partially released into the atmosphere by radiation in the thermal infrared (long wave). On the contrary, green areas and rural environments in general show a reduced UHI effect, that is lower air temperatures, due to evapo-transpiration fluxes. Several studies demonstrate that urban microclimate affects buildings’ energy consumption and calculations based on typical meteorological year could misestimate their actual energy consumption. In this study, two different sets of meteorological data are used for the calculation of the heating and cooling energy needs of an existing university building. The building is modeled using TRNSYS v.17 software. The first set of data was collected by a weather station located in the city center of Modena, while the second set of data was collected by another station, located in the surrounding area of the city, near to the studied building. The influence of the different meteorological situations described by the two weather stations are analyzed and assumed to be representative of the UHI effect. Furthermore, the effects of UHI mitigation strategies on the building energy needs are evaluated and discussed
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