نقش جهان

نقش جهان

نقش جهان سال ششم زمستان 1395 شماره 4 (مقاله علمی وزارت علوم)

مقالات

۱.

Study about Water Sensitive Urban Design Mechanisms; with an Emphasis on Technologies for the Sustainable Management of Stormwater(مقاله علمی وزارت علوم)

حوزه های تخصصی:
تعداد بازدید : ۲۷۰ تعداد دانلود : ۲۴۴
Unsustainable growth of cities and creation a set of contiguous impervious surfaces have result on disorder of natural cycle of water in urban environments. This situation causes flooding and problems due it, pollution of groundwater resources and degrade the quality of the urban landscape by increase the speed, volume and frequency period of runoffs. conventional methods about the stormwater management have failed to demonstrate their effectiveness in this field. Thus, in recent years a new topic are created in the field of urban design that known as "water sensitive urban design". Water Sensitive Urban Design (short: WSUD) is the interdisciplinary cooperation of water management, infrastructer engineering, urban design, and landscape designing. WSUD develops integrative strategies for ecological, economical, social, and cultural sustainability. The purpose of Water Sensitive Urban Design is to combine the demands of sustainable stormwater management with the demands of urban designing, and thus bringing the urban water cycle closer to a natural one. This approach attempts to increase urban sustainability indicators, improve the quality of urban landscape and urban space amenities by offer operational mechanisms in relation to urban design and it attempts not only to close the urban water cycle in its natural cycle and achieve technical goals, but gain optimal utilization of runoff and change the vision of the issue from a threat to a valuable opportunity.The following is a description of some essential methods for sustainable stormwater management. These methods are grouped according to their primary function: water reuse, treatment, detention and infiltration, conveyance, and evapotranspiration. Here is the techniques of water sensitive urban design about stormwater management and link them to urban design concepts, till through that some methods to be introduced that they are more efficient than conventional stormwater management methods about performance, helping to complete the natural cycle of water, environmental sustainability of cities and urban design aspects.
۲.

Thermal Performance of Earth-Sheltered Residential Buildings: a Case Study of Yazd(مقاله علمی وزارت علوم)

حوزه های تخصصی:
تعداد بازدید : ۲۶۰ تعداد دانلود : ۱۸۶
Soil is among the cheapest and most available materials found in the human living environment. Seeking refuge in the heart of earth and benefitting from soil’s thermal property, based on experience, is a strategy employed in the past across some regions. Also the passive systems are amongst the cheapest methods of providing heating and cooling demands of the buildings. These systems experience the lowest impact of environmental degradation while increasing the energy efficiency of the building through decreasing heat gain and loss. The idea of the earth-sheltered buildings is amongst the passive construction that has been embraced by the architects. An earth-sheltered building, as a passive idea, can guarantee, extensively, the reduction of energy consumption and provides the required conditions for thermal comfort. The present study discusses and investigates the thermal performance of earth-sheltered residential buildings in Yazd city of Iran. To predict this type of constructional thermal behavior, subsequent to field and library studies, thermal simulation was employed using Energy Plus software. Energy Plus software is able to simulate the envelopes adjacent to soil. The simulation process is conducted through depth changing of the soil surrounding the sample, assuming its thermal properties are constant. Considering to the results, by increasing the depth of sheltering in amount of soil, its energy consumption saving will increase. In this situation annual temperature fluctuation decreases 50% and it saves about 67% of energy consumption. In addition the most hours set on thermal comfort zone. This subject adds 50 more days to annual Earth-Sheltered acceptable thermal comfort conditions. Moreover due to investigating of the building orientation as an effective element for energy consumption, south orientation is specified as the best position for energy reduction in Earth-Sheltered.
۳.

Thermal Performance Evaluation of Low-E Coated Building Glazing Systems(مقاله علمی وزارت علوم)

حوزه های تخصصی:
تعداد بازدید : ۲۱۷ تعداد دانلود : ۱۹۶
Considering the determinant role of energy efficiency opportunities in the building sector, proposing guidelines and technical solutions in order to improve the thermal performance of glazing systems is in priority in Iran and other countries. In glazing systems, a substantial amount of radiative heat transfer results from absorption and emission. Applying low-E (low emissivity) coatings on the glazing system is a solution for reducing the radiative heat transfer by radiation in glazing systems, without a noticeable decrease of visible light transmittance. By selecting the proper glazing type, in a hot climate, the amount of solar heat gain can be reduced significantly. Vice versa, in cold climate, the heat loss by long wave radiation of inner surfaces can be reduced. In this paper, first, the thermal and optical characteristics of local clear and Low-E glasses have been measured in BHRC (Road, Housing & Urban Development (National) Research Center) laboratory, by the spectrophotometer and then the thermal performance of single and double glazing units, with and without low-E coating, in different orientations (North, South, East and West) are computed, compared and analyzed for cold (Ardebil) and hot (Bandar-Abbas) climates in Iran. The selection of these two cities is based on maximum heating and cooling degree day values obtained respectively for Ardebil and Bandar-Abbas. The simulation results indicate that using double clear glazing unit with low-E coating reduces the energy consumption significantly in very hot climates, using mostly electrical energy for cooling. In cold climates like Ardebil, double glazing with low-E coating has a minor impact on annual heating load, because of the great amount of thermal radiation, even in the cold season, the high cost of low-e coating and the considerable payback time, compared to the building life cycle.
۴.

Parameterization of Geometric Patterns of Islamic-Iranian Space Structure Domes; Case Study: Shabdari Arc(مقاله علمی وزارت علوم)

حوزه های تخصصی:
تعداد بازدید : ۳۸۹ تعداد دانلود : ۶۵۸
In this paper, parametric modeling of five types of common used motifs in Islamic-Iranian architecture including Hashte-Chahar-Lengeh, Hashte-Panj, Hashte-Bazoubandi, Chahar-Lengeh-AlmasTarash and Table Khofte Rasteh are carried out. These motifs are selected because of low condensate of members and the ability to construct them appropriately as load barring rod elements in the dome space structure of slow Shabdari arch. Hence, motifs are projected on the geometry of slow Shabdari arch to create a dome space structure. The problem of parametric modeling of motifs is done in two cases of changing the number of basic modules and changing module production parameters. In the first case, the projection algorithm of basic modules depends on the dissemination coefficients representing the number of modules’ proliferation in horizontal and vertical direction of dome. In this case, the aim is to create sparse or delicate networks based on the form of fixed basic module. In the second case, the parameters used in the algorithm of basic modules themselves relies on the dissemination coefficients to produce new modules based on the considered motifs. Computer simulations for the second case of the problem of motifs’ parametric modeling show that, through a proper choice of the dissemination coefficients, slow Shabdari arch can be converted to common dome space structures such as lamella and ribbed domes.
۵.

Investigating the Effect of Changing the Transmitted Light’s Color on Thermal and Visual Comfort(مقاله علمی وزارت علوم)

حوزه های تخصصی:
تعداد بازدید : ۲۷۱ تعداد دانلود : ۲۰۱
Thermal comfort is one of the key factors for achieving energy saving in the buildings. In the survey of thermal comfort, psychological aspects are as important as the physical parameters such as temperature and relative humidity. If thermal comfort could be achieved by using non–physical parameters, a significant energy and cost would be saved. The aim of this study is to investigate the effect of changing the color of inward daylight (into cool/warm), on sensation of thermal and visual comfort. This study was conducted to answer these questions: to what extent can the lights, which are traditionally called cool and warm, cause the real sensation of cold and heat? What is their influence on thermal and visual comfort? And what is the effect of changing the color of transmitted light on the occupant’s sensation of illumination? Research method is descriptive–analytical; in this study, thermal and visual effects of changing the color of inward light from the windows is surveyed, by using questionnaires, in three naturally ventilated high–schools; and the results were compared with the outputs of PMV simulation analysis. The results show that changing the inward light to a cool color (blue) and a warm color (red) resulted in a difference of 0.33°C in the sensation of thermal comfort. Moreover, the AMV in all cases had a neutral temperature below the PMV’s neutral temperature which was simulated by the software. In lower illuminance levels (lower than 300 lux) blue light aroused more visual satisfaction; but in higher illuminance levels (more than 300 lux), simple windows produced the best visual satisfaction. Red light produced the least visual satisfaction amongst these three. While, blue and red glazing generated better distribution of light in the room, than the witness group.
۶.

Challenges of Using Building Regulations in Architecture from the Perspective of Design Research(مقاله علمی وزارت علوم)

حوزه های تخصصی:
تعداد بازدید : ۲۹۹ تعداد دانلود : ۲۹۰
The use of building regulations in architectural design has been a controversial issue for a long time. From the view point of critics, building regulations inhibit innovation, promote conservative design and are incapable of insuring design quality. From the defenders point of view, some professional mentalities of architects regarding building regulations are problematical and must be changed. The present research aims to illuminate the reasons for the above-mentioned tension between architectural design and building regulations. This is done by examining the structural match between architectural design and building regulations. Seeing from a designer point of view, the paper compares formal characteristics of building regulations with architectural design. Three general characteristics of building regulations are found in contrast to characteristics of architectural design. Building regulations are analytical in nature, while architectural design is a synthesis-oriented act. Building regulations are mainly based on a reductionist approach towards defining design problems and solutions, while innovation and originality are considered as fundamental values by most architects. And thirdly, building regulations are usually framed in a way that matches an evaluative mode of thought, while architects often have to work in a generative and predictive mode. These explain why architects from time to time feel frustrated with regulations. The paper continues to make recommendations to both architectural designers and regulators. To the designers some facts and points are stated to help them better understand the nature and performance of building regulations and guide them safely and positively use regulations in their design process. Addressing the legislators, the paper offers some recommendations to facilitate the use of building regulations in architectural design. Moving towards performance-based regulations, a broader involvement of information technology in building regulations, and production of designer-oriented guidance documents are some of these recommendations.
۷.

Challenges to Design GREEN High-Rise Building in Iran Assessing and analyzing usage of green building technology (case study: Residential Green Towers, Iran)(مقاله علمی وزارت علوم)

نویسنده:
حوزه های تخصصی:
تعداد بازدید : ۳۸۴ تعداد دانلود : ۱۹۰
In recent years, the debate over tall buildings and their impact on the environment has been raised greatly. On the one hand, the need to build tall buildings for various reasons such as: economical, functional, and environmental and on the other hand, High consumption of resources because of tall buildings is a challenge. In recent years, there has been six main approach in the design of high-rise buildings†: High-tech, Monolithic, Kinetic, Scenography, Media tic and Ecological. Ecological approach in the design of high-rise buildings, is realized by sustainable and green architecture. Ecological approach to architecture of high-rise buildings has led to not only the buildings less damage to the environment, but they also promote the quality of the environment. LEED standards at the late of twentieth century is used because of realization of these goals. In spite of a favorable environment for the use of renewable energy in Iran, there are four factors to reach green design: cultural, economic, technological and legal. Also in this condition there are some necessities to build green in high rise: saving energy (by solar panels, wind turbine, GHP system, CCHP), usage of green space in high rise, recycling water, healthy material and sustained construction, double skin façade, site development (green transport). In a case study of green high rise in Iran, renewal energies decreased usage of energy in building from 290kwh/m2 to 75kwh/m2. Also economic factors shows the rise of 1.2-1.4% in cost but 30-35% reduction in energy costs in green high rises. Compared to a conventional building, usage of renewal energies has 17.5% increase in Mechanical costs, 17% in Architecture & 37.5% in green spaces. With double skin façade, total cost increases about 8.2%-8.4% and without 1.2%-1.4%. In maximum condition it is 10% rise in cost compared with a conventional building.

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