جستجوی مقالات مرتبط با کلیدواژه "green roof" در نشریات گروه "مکانیک"

One of the most important goals of sustainable development is to preserve nature and improve it, and the manifestation of sustainable development in the built environment basin is called sustainable architecture. Green roof is one of the new approaches to architecture and urban planning and arises from the concepts of sustainable development, which can be used to increase the per capita green space, improve the quality of the environment. Today, due to the increasing need for energy and the limitation of fossil fuels as depleting and polluting sources of the environment, the need to use more renewable energy sources is felt. One of the increasing uses of energy is thermal energy. One of the methods of thermal energy storage is the use of phase change materials. This research has been prepared with the aim of thermal optimization of green roof using phase change materials. By selecting biodegradable materials as phase change materials used in the roof, the research was conducted in three models and three different uses, using Energy Plus software. According to the results, the green roof model optimized with phase change materials in all three different uses of the building has increased the temperature in the building in cold seasons and significantly increased the temperature in hot seasons, and achieved thermal comfort. Therefore, according to the results, using green roof separately causes more temperature balance.

In the present study, the energy performance of a villa building in Isfahan was studied during a year using DesignBuilder (Ver. 6.1) and the results were evaluated with energy bills including both gas and electricity consumptions. After identifying the energy performance weaknesses of the building, the skin was enhanced in two scenarios to meet the requirements of code No 19 and ASHRAE 90.2. It is found that the energy required for cooling and heating of the existing building can be saved by 63% and 70%, respectively, in compliance with the requirements of code No 19 of and ASHRAE 90.2. The results also show that despite all the weaknesses of code No 19, the energy intensity of the building's sector in Iran can be saved considerably only by following the regulation. The role of green roofs in terms of the energy saving in these two scenarios was also studied. In addition to other benefits of green roofing from architectural and environmental perspectives, an extra reduction in energy consumption by 9.5% and 4% can be achieved by a typical green-roof in a building based on code No 19 and the requirements of ASHRAE 90.2.

One of the concerns in the current world is the depletion of non-renewable energies reserves. In the urban space, the factor affecting such energies are educational buildings with high energy consumption. Green roof system is a suitable solution to improve energy consumption in these buildings. This research aims to optimize energy consumption in educational buildings and with descriptive-analytical research method, has addressed the issue of green roof system with Minimum load on the roof structure and its impact on energy consumption of these buildings. Also, a sample of primary school in Isfahan city with a simple roof was simulated in terms of energy consumption by Design builder software. After that, this primary school was simulated again with all main information about green roof system. Finally, the results show that green roof system with grass vegetation that has shallow depth of root and growing medium, has caused a minimum load on the roof structure and optimized energy consumption of cooling and heating systems of this educational building and reduced the total energy consumption of this building by 4.8% during one year.

Cooling and heating energy accounts for a significant portion of the total energy consumption in residential sector. Building envelope is exposed to sunlight and outside air and therefore have a significant role in determining the thermal loads of buildings. Meanwhile, roofs which are exposed to sunlight all the day long are important envelope components and have a significant share of buildings energy consumption. Therefore, applying appropriate roof solutions can significantly reduce building energy consumption for air-conditioning and improve indoor comfort conditions. This paper aims to investigate the effect of different roofing techniques on thermal performance of a single-storey residential building with two types of uninsulated and insulated configurations under different climatic conditions of Iran. For this purpose, different cool roof albedos 0.5, 0.7, and 0.9 and two types of green roofs, GR with actual local rainfall and wet GR, are considered. The thermal loads of the buildings are calculated using the DesignBuilder software and compared with a conventional cast concrete roof. The results show that by choosing an appropriate type of roof technique, the total air-conditioning energy requirement of the building can be reduced between 7-31%, depending on the building configuration and climatic condition.

In the current study, the modeling and simulation of energy consumption for a two-story building with green roof in three different climates of Iran (Bandar Abbas: hot and humid, Tehran: mild and dry, and Tabriz: dry and cold) have been performed. This simulation aimed at investigation of the effects of the green roofs on reduction of thermal loads on the building and its role in reducing heat flux through the roof of the building. As the method, the building has been modeled by a software. This three-dimensional model by Energy Plus simulation software has been done. Simulation has been performed for different times of a year. For each of the three cities, a typical building with asphalt roof and a complete identical building with vegetation on its roof instead of asphalt, on its last layer, have been simulated and the results have been compared. The heat pumps have been used to provide heating and cooling loads on the building. The results of the simulation indicated that by the use of green roof, the annual baseline electricity consumption for heating and cooling loads were reduced up to 16.3%, 12.5% and 23% in Tehran, Tabriz and Bandar Abbas, respectively. According to the results, the use of green roofs in the tropical regions (Bandar Abbas) is more efficient compared to cold regions (Tabriz). The reason behind this phenomenon is the effect of the green roof as a cooler on the performance of the studied building's cooling system. The sensitivity analysis have shown that the energy consumption of described building is strongly dependent on soil thickness and vegetation density on the green roof structure as the more the soil thickness is, the better thermal insulator will be, and the higher the vegetation density is, the more powerful it will be, to prevent radiation from the sun.