Suchergebnisse

Green façades consist of the application of vegetation on buildings' vertical enve-lope. The integration of vegetation into the building fabric improves not only the aesthetic appearance, but also the energy performance of the building itself. The introduction of green façades mainly aims at a passive thermal control of build-ings' for enhancing sustainability of the built environment. An experimental green façade was tested at the University of Bari, in a Mediterranean climate context. The experimental green façade was south-exposed and realized with evergreen plants, following the characteristics of the indirect typology. A portion of the south wall was left bare to be used as a control for comparison. The contribution of the green façade in terms of passive climate control was particularly relevant during summer. Vegetation affects the boundary climatic conditions and the surface temperature. A reduction in sensible air and surface temperature of up to 2.2°C and 6.7°C, respectively, was recorded. The wall behind vegetation received 95.6% less solar radiative energy than the bare wall. These results were a direct conse-quence of the two main cooling mechanisms that characterize the green façade, the evapotranspiration and the shading effect. These effects affected the heat transfer reducing the energy input through the covered wall. The reduction of the incoming heat through the covered wall was read as energy saving, since it inevita-bly affects the building energy demand for cooling. It was found that the green fa-çade allowed a mean daily energy saving of 1.1 MJ m-2 and that 90.9% of this was obtained at daytime. These findings contribute to increasing the knowledge of en-ergy functioning and of the real advantages provided by green façades.

According to the European Environment Agency, the agricultural sector consumes around 3% of the total energy consumed in the European Union and specifically 28.8 million tones of oil equivalent in 2016. Although between 2005 and 2016, the final energy consumption in the EU decreased in the fishing, agriculture and forestry sectors by 24.7 % the energy required in this sector is considered to have a significant contribution to the energy related policies of the EU. Greenhouses constitute a major energy consumer of the agricultural sector in the European Union. Although strictly speaking, greenhouses differ from buildings in several ways, such as the construction, the building systems and the use, the principles used to analyse the energy consumption of greenhouses, as well as the strategies to control their energy performance are quite similar with those of the building sector. This study aims to present the recent advancements in the analysis of the energy performance of greenhouses, with a special focus on next generation greenhouses, also known as intelligent greenhouses. The main energy consumption sources in greenhouses, as well as their normalized intensity is presented. State-of-the-art automations to control the energy performance of greenhouses, as well as intelligent systems used to achieve the required thermal conditions in greenhouses, such as automation systems, infrared heating and advanced covering materials are presented. The main challenges of the intelligent greenhouse sector, as well as the requirements for the development of new energy related standards for greenhouses are also discussed. The study concludes with the presentation of the energy performance of a greenhouse, considered as intelligent, of the Department of Agricultural Technology of the Technological Education Institute of Western Greece in Patras, Greece. Detailed data logging of the temperature and indoor conditions of an intelligent greenhouse are analysed and compared with regard to contemporary greenhouses, revealing and quantifying the potentials of this sector in the energy saving strategies of Greece and the EU.

According to the European Environment Agency, the agricultural sector consumes around 3% of the total energy consumed in the European Union and specifically 28.8 million tones of oil equivalent in 2016. Although between 2005 and 2016, the final energy consumption in the EU decreased in the fishing, agriculture and forestry sectors by 24.7 % the energy required in this sector is considered to have a significant contribution to the energy related policies of the EU. Greenhouses constitute a major energy consumer of the agricultural sector in the European Union. Although strictly speaking, greenhouses differ from buildings in several ways, such as the construction, the building systems and the use, the principles used to analyse the energy consumption of greenhouses, as well as the strategies to control their energy performance are quite similar with those of the building sector. This study aims to present the recent advancements in the analysis of the energy performance of greenhouses, with a special focus on next generation greenhouses, also known as intelligent greenhouses. The main energy consumption sources in greenhouses, as well as their normalized intensity is presented. State-of-the-art automations to control the energy performance of greenhouses, as well as intelligent systems used to achieve the required thermal conditions in greenhouses, such as automation systems, infrared heating and advanced covering materials are presented. The main challenges of the intelligent greenhouse sector, as well as the requirements for the development of new energy related standards for greenhouses are also discussed. The study concludes with the presentation of the energy performance of a greenhouse, considered as intelligent, of the Department of Agricultural Technology of the Technological Education Institute of Western Greece in Patras, Greece. Detailed data logging of the temperature and indoor conditions of an intelligent greenhouse are analysed and compared with regard to contemporary greenhouses, revealing and quantifying the potentials of this sector in the energy saving strategies of Greece and the EU.

According to the European Environment Agency, the agricultural sector consumes around 3% of the total energy consumed in the European Union and specifically 28.8 million tones of oil equivalent in 2016. Although between 2005 and 2016, the final energy consumption in the EU decreased in the fishing, agriculture and forestry sectors by 24.7 % the energy required in this sector is considered to have a significant contribution to the energy related policies of the EU. Greenhouses constitute a major energy consumer of the agricultural sector in the European Union. Although strictly speaking, greenhouses differ from buildings in several ways, such as the construction, the building systems and the use, the principles used to analyse the energy consumption of greenhouses, as well as the strategies to control their energy performance are quite similar with those of the building sector. This study aims to present the recent advancements in the analysis of the energy performance of greenhouses, with a special focus on next generation greenhouses, also known as intelligent greenhouses. The main energy consumption sources in greenhouses, as well as their normalized intensity is presented. State-of-the-art automations to control the energy performance of greenhouses, as well as intelligent systems used to achieve the required thermal conditions in greenhouses, such as automation systems, infrared heating and advanced covering materials are presented. The main challenges of the intelligent greenhouse sector, as well as the requirements for the development of new energy related standards for greenhouses are also discussed. The study concludes with the presentation of the energy performance of a greenhouse, considered as intelligent, of the Department of Agricultural Technology of the Technological Education Institute of Western Greece in Patras, Greece. Detailed data logging of the temperature and indoor conditions of an intelligent greenhouse are analysed and compared with regard to contemporary greenhouses, revealing and quantifying the potentials of this sector in the energy saving strategies of Greece and the EU.

According to the European Environment Agency, the agricultural sector consumes around 3% of the total energy consumed in the European Union and specifically 28.8 million tones of oil equivalent in 2016. Although between 2005 and 2016, the final energy consumption in the EU decreased in the fishing, agriculture and forestry sectors by 24.7 % the energy required in this sector is considered to have a significant contribution to the energy related policies of the EU. Greenhouses constitute a major energy consumer of the agricultural sector in the European Union. Although strictly speaking, greenhouses differ from buildings in several ways, such as the construction, the building systems and the use, the principles used to analyse the energy consumption of greenhouses, as well as the strategies to control their energy performance are quite similar with those of the building sector. This study aims to present the recent advancements in the analysis of the energy performance of greenhouses, with a special focus on next generation greenhouses, also known as intelligent greenhouses. The main energy consumption sources in greenhouses, as well as their normalized intensity is presented. State-of-the-art automations to control the energy performance of greenhouses, as well as intelligent systems used to achieve the required thermal conditions in greenhouses, such as automation systems, infrared heating and advanced covering materials are presented. The main challenges of the intelligent greenhouse sector, as well as the requirements for the development of new energy related standards for greenhouses are also discussed. The study concludes with the presentation of the energy performance of a greenhouse, considered as intelligent, of the Department of Agricultural Technology of the Technological Education Institute of Western Greece in Patras, Greece. Detailed data logging of the temperature and indoor conditions of an intelligent greenhouse are analysed and compared with regard to contemporary greenhouses, revealing and quantifying the potentials of this sector in the energy saving strategies of Greece and the EU.

The greenhouse cultivation system in European countries represents one of the most energy-intensive sectors in the agriculture and agro-industry sector. In this regard, renewable energies represent an innovative solution to reduce energy costs and environmental impacts. Both, the energy demands and the economic aspects are analyzed with regard to the main energy users, i.e.: heating and cooling systems, lighting and pumping for irrigation. This work considers the use of solar photovoltaic and thermal energy. The use of semi-closed greenhouses is also considered.

A sustainable and environmentally alternative to commonly used air conditioning systems can be the solar cooling system due to the use of renewable and clean energy. Solar absorption systems can be used for greenhouse cooling in areas with high outdoor temperatures and solar radiation levels. These systems take advantage of the simultaneity between the solar energy availability and the greenhouse cooling demand allowing the reduction of conventional electricity and water consumption. This paper presents the results of the application of a solar cooling plant for the climate control of a greenhouse at the University of Bari, Italy. The experimental plant consists of a Mediterranean greenhouse, having a surface of 300 m2, and of a single effect LiBr-H2O absorption chiller fed by evacuated-tube solar collectors. Two different localized systems were chosen for the distribution of cold inside the greenhouse: the first system presents pipes placed centrally on the cultivation vessels; the second consists of pipes in contact with aluminium plates and of a transparent EVA film, used to border an area close to plants. The distribution system of cold with pipes, plate and EVA film provided a slightly higher cooling capacity due to the presence of the plates which increases the ability to dissipate energy.