مسکن و محیط روستا (Dec 2019)
Solar Radiation Absorbed on the Neighborhood Scale regarding the Rural Fabric in Cold Climate Regions
Abstract
Environmental subjects, in general, and energy issues, in particular, do not have a prominent role in rural research projects in Iran, and this is accompanied by negative environmental consequences, such as excessive energy consumption in rural housing. A significant amount of energy in villages is used up by dwellings, and the form of rural fabric is a major factor affecting this issue. Most of the previous research has focused on the analysis of energy use on a small scale and in the form of a single building while; the environment and surroundings of buildings affect energy consumption as well. Therefore, the energy usage in the neighborhood scale has been largely overlooked and needs a thorough investigation. Designing the neighboring units in a manner that absorb the maximum solar radiation may have a direct effect on the thermal behavior of individual buildings. The primary goal of this paper is to analyze the effect of the rural fabric’s form and also floor area ratio (FAR) on solar radiation absorption by rural buildings. Thus, the effects of three parameters in rural fabric i.e. the orientation of buildings, the height of the buildings and the rural building configurations, on annual solar radiation absorption have been studied. In the first step, the existing forms of rural housing and different layout of the rural fabric have been identified and seven patterns for rural housing were found. These seven patterns include Type A: building footprint located on the northern part of the plot; Type B: U-form; Type C: L-form; Type D: the central courtyard form; Type E: Two-sides houses; Type F: the central courtyard and an exterior yard; Type G: Kiosk form. Then, the effect of two orientation and height parameters on the selected patterns is investigated. To measure the effectiveness of the orientation parameter on the amount of solar radiation absorption, each of the mentioned patterns is rotated 180 degrees between 90 to 270 degrees. In the next stage, the number of building floors has changed from one to three, and once again the amount of solar radiation absorption has been measured. Thus, 7560 models have been simulated by using Grasshopper plugin to Rhino software and then graphical data have been attained using excel software. The results imply that the impact of “form of rural housing”, “the height of building”, and “the orientation of building” on solar radiation absorption of rural houses is 70%, 40%, and 8% respectively. And, if constant Floor Area Ratio is assumed, the change in pattern type affects the solar radiation absorption. Also, results show that "the central courtyard and an exterior yard" has always had the highest amount of solar radiation absorption than other indigenous housing patterns. The next priorities are “the central courtyard” and “Kiosk” patterns in terms of solar radiation absorption. Furthermore, in rural residential fabric with the same FAR, if we change the height of buildings, we will see different results in terms of the amount of solar radiation absorption and the energy consumption of the buildings. The findings of the present study influence the design of rural fabric, the determination of FAR, and the type of rural housing pattern for the planning and designing of villages.
