In recent years, natural disasters, such as the heat wave, mortality rates have increased due to rising air temperatures and environmental problems, such as air pollution due to the accumulation of heat in cities, and has led to increase attention to decling these environmental problems. It is a way to create an Outdoor thermal comfort, in addition to promoting human health as a factor in reducing the air temperature in urban environments. Therefore, man-made and natural spaces in cities can provide comfortable environments.We often think of people living their life inside buildings and we may not see that in fact for one reason or another we spend much of our time outside – between the buildings.The spaces and places of these, and many other everyday activities, have a special social, cultural and even economic significance.Thus we have to make great efforts by designers and planners to reduce air temperature and reduce air pollutants that enhance the presence of people in these spaces. Outdoor thermal comfort in urban open spaces is one of the most important indicator of quality of life in the city. Outdoor thermal comfort enhance presence of people, it can boost their health. Variables such as buildings height and orientations of buildings, space between the buildings, open spaces surface and building material have effects on outdoor thermal comfort. The main aim of this study was to examine the influence of urban geometry on outdoor thermal comfort in time- honored and state-of–the-art tissue in Mashhad. Moreover, urban geometry such as urban canyons and green spaces at pedestrian level are effective factors and there is limited attention in Iran. Evaluating thermal comfort of the locals may help architects and planners to deal with urban problems by identifying thermal comfort needs in indoor and outdoor environments, so that the intensity of temperatures is reduced in open spaces by using design elements. In Iran, thermal comfort issues in academic studies are more focused on indoor spaces, and in recent years, approaches to outdoor thermal comfort have increased.This study focuses on effects of urban geometry on outdoor thermal comfort in two urban areas PACHENAR and SHAHED tissue in Mashhad. The first part of the article examines researches carried out in the subject area of the paper, and then, in the next section, Theoretical foundations of the articles, thesis and books have been extracted. Air temperature, wind speed, mean radiant temperature (MRT), and the physiologically equivalent temperature (PET) are simulated with ENVI-met and Rayman to highlight the strengths and weaknesses of the existing urban geometry in summer season.

The methodology is practical research based in two parts. Firstly the framework theory is extracted from researches such as papers, books and dissertation, The climatology data collected from weather station of Torogh which is located near Mashhad. After that Gis maps are used for neighborhood. In order to reach the PET values, the proposed method is applied to an urban canyon, which is simulated in terms of mean radiant temperature and PET, combining ENVI-met (http://www.ENVI-met.com) and Rayman. Firstly a simulation of the case study model are conducted in ENVI-met. Secondly, some of the key results and values from ENVI-met are imported into Rayman and other simulation runs.

The three-dimensional micro climate model ENVI-met is designed to simulate the surface-plant-air interactions in urban environment. ENVI-met software is a useful tool for planners to analyze and predict the thermal comfort impacts of various factors. ENVI‐met is a 3D model, which seeks to replicate the major atmospheric processes that affect the micro climate. This model simulates wind flows, radiation fluxes, temperature, humidity and other parameters, based on the fundamental laws of fluid dynamics and thermodynamics. which is able to simulate the interactions between different urban surfaces, vegetation and the atmosphere. ENVI-met allows analyzing the effects of small scale changes in urban design on micro climate under different mesoscale conditions. A major shortcoming with ENVI-met is that buildings which are modeled as blocks where width and length are multiples of grid cells, have no thermal mass. Input data required to initiate ENVI-met simulations are:• Wind speed and direction at 10 m above ground level; • Roughness length (Zo); • Initial temperature of atmosphere; • Initial temperature and humidity of the soil; • Specific humidity at 2500 m; • Relative humidity at 2 m. The model calculation includes:• Short-wave and long-wave radiation fluxes with respect to shading, reflection and re-radiation from building systems and the vegetation;• Transpiration, evaporation and sensible heat flux from the vegetation into the air, including full simulation of all plant physical parameters. In this study, simulation was carried out in the summer (August) and based on the data of the meteorological station of Mashhad. This simulation was selected on August 28, 2017, during the sunrise and sunset times between 6 AM and 20 AM, , which represents the hottest day in summer.

The Rayman is produced by Matzarakis. It model has been developed in the Meteorological Institute of the University of Freiburg in Germany in 1998. This model is developed to simulate the short and long wave radiation flux densities from the three dimensional surroundings in simple and complex environments. RayMan is in fact a freely available radiation and human bioclimate model. The aim Of the RayMan model is to calculate radiation flux densities , sunshine duration, shadow spaces And thermo-physiologically relevant assessment indices using only a limited number of meteorological and other input data. For such models to be applied in simple situations, the following atmospheric parameters are required:– direct solar radiation – diffuse solar radiation – reflected short-wave radiation – atmospheric radiation (long-wave) – long wave radiation from the solid surfaces.The following parameters describing the surroundings of the human body also have to be known:– sky view factor – view factor of the different solid surfaces – albedo of the different solid surfaces – emissivity of the different solid surfaces
Assessment of microclimate and thermal comfort outdoors
Due to the wide use of the PET index in different climate studies and the ease of expression of oudoor thermal comfort of individuals, in this paper, the PET index is calculated. Since these numbers are not localized in Iran, and in particular to Mashhad. The range of 23 is based on the Matzarakis and Mayer studies as a thermal comfort range. On the other hand, trees play an important role in this study. The simulation carried out in Envi-met has also been based on field observations of the density of these trees, which is called the LAI index (LAI).Dense trees with 10 m height (LAI = 4.73) and very dense trees with 15 m height (LAI = 9.35) were designed for simulating the vegetation. In addition, grass with 0.1 m height (LAI = 0.03) was also used.
Model Calibration: In order to make the results of these models based simulations more credible, the model had To be calibrated. The input values have to be changed slightly, so that the output values turn Out to be a more accurate representation of reality. In order to do that The model was calibrated with on-site long-term measurements of air temperature (Ta), relative humidity (RH), wind speed (Ws) and direction (Wd) at two tissues as well as properties of ground surface materials .

Urban Heat Island (UHI) is considered as one of the major problems in the 21st century posed to human beings as a result of urbanization and industrialization of human civilization. In this study, effects of the variation of physical and geometrical properties of the urban fabric (i.e. cool roofs including green and white roofs and perviousness of paving materials) on the urban micro-climate and outdoor thermal comfort were investigated using 3dimentional urban micro-climate model, ENVI-met. Based on the predicted results, increasing the amount of vegetation and permeable pavements can cool the air temperature down by up to 3 K.

1. Urban microclimatic conditions have a very serious impact on the energy consumption of buildings, outdoor comfort conditions and pollutants concentration. Urban heat island phenomenon in combination with global climatic change deteriorate the microclimatic conditions that are characterized by increased ambient temperatures, longer duration of hot spells and more frequent heat waves)Santamouris, 2007, 2011). Various studies performed have shown that urban heat island may increase the cooling energy demand of urban buildings between 20 and 100% (Hassid et al., 2000; Santamouris et al., 2001; Papadopoulos et al., 2001; Kolokotroni et al., 2009; Ihara et al., 2009). Mitigation techniques are aiming to counterbalance the heat island phenomenon by the intensive usage of green spaces. Applications of highly reflective materials, decrease of the anthropogenic heat, solar control of open spaces, use of environmental heat sinks and increase of the wind flow in the canopy layer, and more importantly than these cases using cool paving materials in paths and roads. This paper presents a study by the goal of investigating the influence of urban transportation network covers and paved surfaces on microclimatic conditions using common brick, cement concrete, and asphalt (with basalt) materials. The first case is applied in paving of the pavement tradition cities of Iran and two other cases are applied in paving of the pavement modern cities of Iran. The purpose of this research is presenting the performance of three materials used as paving materials in urban network pavement and investigating their impacts on reduction or increase of the arrogance heat island phenomenon and on the peak ambient temperature during a typical summer day. This try to improve outdoor comfort conditions of urban space, as the result of a real project in Tehran (Iran), in order to recommend the best paving materials. 2. In this study, to investigate the effects of surface coating on the temperature and on wider scale urban spaces, the following stages have been carried out. The first, texture design of site based on the requirements specification and the field space divided by type of land uses, the second, collection of the atmospheric raw data from Mehrabad weather station, corresponding to July as the hottest month in Tehran. The third gathering the specifications of Asphalt, Concrete, Cement and solid bricks, and entering details of each one in configuration editor of Envi-met. Forth, designing the site in Eddi program in Envi-met, to defines type of material (asphalt, cement concrete, and solid brick), land cover of the site on the net, program of soil model on three separate models for simulation. Fifth, definition and locating 7 virtual receptor on the site in Envi-met as reference points in recording and receiving atmosphere data during simulation process to statistical analysis and numerical simulation (quality of site selection of receptors show all changes of temperature for each of the models). ENVI-met is a three-dimensional microclimate model designed to simulate the surface-plant-air interactions in urban environment with a typical resolution of 0.5 to 10 m in space and a typical time frame of 24 to 48 hours with a time step of 10 sec at maximum. This resolution allows analysis of small-scale interactions between individual buildings, surfaces and plants. Typical areas of application are Urban Climatology, Architecture, Building Design or Environmental Planning, just to name a few. The energy budget is calculated at the ground surface. The results are the surface temperature and humidity as well as the fluxes of sensible and latent heat. The ground surface and the walls are used as boundary conditions for the atmospheric model (ground surface and walls) and for the soil model (ground surface).The temperature of the walls and the roofs is calculated for each grid point with respect to surface orientation, albedo and heat exchange with the temperature inside the building. The heat exchange between the building walls/roof and the atmosphere can be calculated using the wind field, the surface temperature and the local turbulence. 3. This research has showed that the use of brick (made of clayey) paving material contributes to the reduction of the peak ambient temperature (potential temperature) during a typical summer day up to 2◦C and 0.5◦C compared with asphalt (with basalt) cement concrete paving materials, respectively. At the same time, the surface temperature in the site was decreased by 10◦C in brick paving material compared with asphalt (with basalt) paving material and 4◦C in comparison with cement concrete paving material, while comfort conditions have been improved considerably in the assessment with Comfort index. 4. Heat island increases temperature in urban areas, increases the energy consumption for cooling purposes and affects the global environmental quality of cities. The use of advanced mitigation techniques highly contributes to decrease temperatures and improve comfort in open urban areas. Autochthonous and tradition cool paving materials, e.g., brick, presenting a high solar reflectivity and emissivity have been proposed as an effective mitigation technique when applied to open spaces against asphalt (with basalt) and cement concrete materials. Although many experimental data are available to evaluate the performance of brick material in isolated buildings, very limited information is available concerning the mitigation potential of the brick material when applied in open urban areas. The results of the specific climatic conditions in the three-dimensional microclimate model ENVI-met of site fabric have showed that the extensive application of brick pavements, under the specific climatic conditions, may reduce the peak daily ambient temperature during a typical summer day up to 1.5 ◦с while surface temperatures were reduced up to 10◦C against cement concrete and asphalt pavements. In parallel, calculations of the thermal comfort conditions in the site fabric space have shown that brick crossings improve considerably comfort conditions. In particular, under strong wind conditions, advection phenomena may dominate and the impact of local convection and radiation phenomena will be diminished. In addition, for lower levels of the ambient temperature and solar radiation, the summer contribution of brick paving material is expected to be reduced. Finally, the use of brick paving materials is not expected to decrease the ambient temperature during the winter period. The overall analysis has shown that the use of brick crossings is an efficient strategy in order to reduce the intensity of heat island in urban areas and to improve the global environmental quality of open areas. Therefore, it can be concluded that the use of brick paving materials is a very efficient mitigation technique to improve thermal conditions in urban areas of Iran.

Climate change trend is at the forefront of global research priorities, so that in the case of rising temperatures in most countries, in particular, the warm and dry climate will be reduced by the presence of people in open spaces and refuge in open spaces. This reduces the health of people and diseases caused by the increase in temperature, in addition, energy consumption in buildings due to long-term use of closed space. Therefore, due to the need to provide climate solutions to improve the air quality of open spaces, this research seeks to measure the level of compatibility of the traditional courtyard with the climatic conditions in the city of Shiraz. In an attempt to answer this question, the use of a set of conditions such as percentage of open space, orientation, sky viewing angles, vegetation, water and specific materials can influence the comfort of heat and the amount of people using space. Therefore, with the aim of determining the priority of the effect of the above components, seven houses of the Qajar period in Shiraz were selected and using the ENVI-met 4 basic software, the thermal comfort level was calculated based on the PMV index. The results of the research indicate that the courtyards of the houses with the lowest visibility of the sky and the area have more shading, resulting in a better external thermal comfort for the inhabitants. However, factors such as shadowing of trees and the effect of moisture in water basins should not be ignored in stretching the rugged air of the central courtyards. The coefficients obtained from the analysis showed a significant correlation between the "average radiant temperature" and "PMV thermal comfort index" in the warm and dry climate of Shiraz. Kay words: Shiraz’s Houses, Climate wisdom, External thermal comfort, Central courtyard, ENVI-met,ghajar era.

The increased average of non-renewable energy consumption in the residential sector and not using the passive techniques, which are often based on the vernacular architecture concepts and principles and climate, have led to energy waste and increased costs. Due to humidity and excessive heat in summer at noon, Amol exceeds the thermal comfort and needs natural ventilation. The current study aims to study the effect of dimensions and layout of the opening on the natural ventilation and reduction of energy consumption. First, reviewing the research background, natural ventilation was determined as the main component of the building design in this climate, and the operational principles of the stated component were extracted using Climate Consultant. Among the operational principles, the value of the opening area was determined as the main criterion of the climate design using the AHP method. With simulating a one-story residential building with an area of 75 square meters in Amol’s climate in Envi-Met software and inputting climate information obtained from Climate Consultant analysis in Envi-met, the wind direction was north and north-western. The building understudy was simulated in Design Builder software. By comparing the window to surface percentage ratio and annual energy consumption, the ratio of 30% with the minimum energy consumption equivalent to 6839.87 kwh was considered the criterion for studying the opening effect. Windows of the residential building were considered as three parts to study the effect of the opening dimensions. In northern and southern sides where one-third of the window was closed, the minimum energy consumption value as the total of thermal and cooling loads was 7298.93 kwh, indicating the effects of the dimensions of the opening in the natural ventilation of the building in the humid and moderate climate.

Urbanization and population growth in metropolitan areas, on the one hand, and the growth of large-scale industrial activities, on the other hand, have led to changes in the climate of urban areas.This research is based on the classification of types of research in the category of descriptive and explanatory studies. Based on the results in the category of applied studies. It is based on qualitative and quantitative research processes. The research method is a combination of descriptive-analytical methods and software simulation with software Envi-Met software. Data is quantitative and qualitative related to the quality of space. Implementing it includes conceptual and theoretical modeling, software modeling, change in the type and amount of variables and testing the software model to find optimal answers. For this purpose, a basic model based on common urban forms in Tehran is selected and in which indicators such as the location of building blocks, orientation, the distance between blocks, the height of blocks in Envi-Met software are modeled and based on the index of thermal comfort and degree. PMV temperature was evaluated. According to the software outputs, it can be concluded that the location, distance, orientation and height have a positive effect on reducing thermal islands and providing thermal comfort conditions

Building form has a great influence on energy conservation and a correct architectural design can play a significant role in this field. Shading and its impact on thermal comfort of the residents are among the concepts which are of great importance in the subject of buildings' architectural design with regard to the regional climate. In this paper, an attempt was made to analyze the thermal behavior extent of these semi-open spaces in residential complexes of Mashhad County with the help of ENVI-met software. Therefore, the present paper, which is based on a simulation approach, investigates and analyzes the thermal comfort in semi-open spaces. By comparing different models simulated with Envi-met software, it can be found out that none of the investigated models achieve the thermal comfort conditions on the day of the summer solstice, but the double-closed model, located on the central side of the building, provides the maximum amount of thermal comfort conditions at a rate of 6 hours on the day of the winter solstice. After this model, the one side closed ones, located in the central side of the building, and three sides closed ones, located in the western side of the building, provide the most thermal comfort time. The weakest models in terms of the duration of providing thermal comfort conditions are the one sided closed and double-closed models located on the west side of the building, which never provide thermal comfort conditions during the summer and winter solstice days.

With the wind permanent flow in the cities, obtaining the minimal pollution in the environment is accessible. Different policies have been considered for optimization of cities such as attachment and or reduction of building parts like air-traps, ceiling forms and so on. Due to population growth in cities and the increasing need for resettlement these people in the cities, inevitably, to the high-rise buildings have gone. The people living in high-rise buildings to meet the needs of their vital urban open spaces are forced to use. To have knowledge about air pollution through buildings, the CFD based software of Envi-met is used. In this case, we can say that the best angle to transfer pollution is the angle of 30 degrees. Also in an ideal case with imposed changes in the form, we could enhance the problem by better navigation of inside wind of urban canyons into spaces between blocks of buildings that have the capacity to trap the particles. Final it is found that we may be able to have more optimal results for transition of pollutions by suitable orientation of blocks against the wind direction of blow.

Designing and planning for residential development are among significant components of any planning or urban design efforts. In many countries, residential types vary greatly between regional markets, and they vary within a single municipal jurisdiction too. Housing types acceptable in a locale may not be culturally, economically or environmentally viable even a short distance away. Among the main issues in housing practice are the housing block types. Block types refer to the arrangement of the relationships between mass and space in an individual plot and then in a whole block shape. This also depends on many various factors such as building types (e.g. single family, multifamily, detached or attached, etc.), street patterns (e.g. in case of total width), open space patterns (e.g. courtyard, back yard, etc.), environmental condition (e.g. macro and micro climatic zone, slope, scope, etc.), in which every single factor adjudicates to bring about some diverse block patterns. Therefore, the more variety of conditions needs to meet the more variety of massing patterns. In the recent half century, there has been emerged a massing pattern through the spatial transformation of house, in which the mass is placed in north side of plot and then courtyard in the south side of it. Because of prevalence of this pattern throughout the whole country and also within several decades, it can be taken as a part of planning tradition of contemporary, rural and detached urban fabrics of Iran. This article aims to survey the mentioned pattern and answer the questions which are the insufficiencies of this pattern at first. Then it studies how some changes in massing pattern could cause wide spread microclimate variations. In this case, two massing patterns have been compared. The first pattern is a current one that has been addressed before. The second is a proposed pattern which is similar to the current pattern, except in pitching, on parcel. Indeed, in the proposed massing pattern, the north plots are covered from line of plot in street proximity. Therefore the microclimatic variants which influence on thermal comfort have been compared. The microclimatic variants include mean radiant temperature, relative humidity, air temperature and wind flow (direction and speed). Envi-met model has been used to evaluate the variants. The paper is going to apply Leonardo and Xtract software’s in order to extract required outputs in terms of graphics and numeric. The findings indicate some prominent differences between the two compared patterns pro of the proposed one. Indeed, based on precise mathematical calculation, the proposed pattern has 4 levels higher than the existing one within the thermal comfort variants. Especially, in relation to the mean radiant temperature variant that is known as a critical scale to determining the comfort in exterior condition. It proves that only replacing the mass in a given plot can make great improvement on saving energy and is mainly suitable for microclimate condition. Also it poses a question for not renewing the regulatory context to bring about the better block patterns and the existing conditions have been left on its own.

Today, the rapid growth of urbanization and the increasing trend of greenhouse gas emissions, which continue to increase despite international efforts, have aggravated the climate change issue. Reaching an approach that balances the natural and built environment is one of the most essential human objectives in forming a favorable environment. To achieve such a goal, planning and designing cities in line with the principles of climate design is the primary and most crucial concern in this field of activity. The proposed criteria will encourage the process of becoming more energy resilient by planning a holistic approach to various and complex aspects of cities and looking at cities as dynamic complex systems in each urban functional area. Urban resilience refers to the ability of an urban system and all the social, environmental, and technical networks that make it up, in time and space scales, to maintain or quickly return to the intended function in the face of disruption, to adapt to rapid change and transformation of systems that limit current or future adaptive capacity. In the field of urban energy, resilience is inevitably linked to the concept of sustainability. However, the new towns planned in Iran to respond to the problems of the greater mother city at the level of metropolitan areas have not sufficiently considered the climatic conditions and local characteristics in the design. Therefore, according to the necessity of strategies to reduce energy consumption in the increasing trend of climate change, this research aims to investigate and analyze urban physical form design principles with an energy-based resilience approach to improve Thermal Comfort in Sadra New Town on the northwestern edge of Shiraz, the capital of Fars province. For this purpose, library studies and quantitative measurement using ENVI-met sub-climatic analysis software have followed the descriptive-analytical research method. In the first step, energy resilience criteria based on global energy resilience rating systems and theoretical research conducted, including smart location, resources and energy, transportation and use, neighborhood form and development pattern, and placemaking, were identified as five layers. Then, after designing the main structure of a sample neighborhood in Sadra according to the explained criteria for the physical form and energy-based resilient design and the physical and climatic analysis of the site, a series of selected points were simulated in Envimet software for which the thermal comfort index or the Predicted Mean Vote (PMV) was extracted in the hottest month of the year. The evaluation result showed that no part of the neighborhood is in the optimal temperature range. In other words, the area needs help in terms of the thermal comfort of pedestrians in the summer season during the hot hours of the day. Finally, design guidelines and regulations were presented on a smaller scale by measuring the plan’s deviation from thermal comfort standards compared to the physical design, sky visibility factor, and other climatic indicators. The outcome of this research is to re-composing physical form with an energy-based resilience approach in an urban neighborhood, presenting strategies and policies that are extensible to new developments.