بررسی تاثیر سایه‌بان‌های متحرک الحاقی به فضاهای نیمه‌باز بر مصرف انرژی سالانه‌ ساختمان‌های مسکونی تهران

یکی از راهکارهای موثر در معماری گذشته‌ ایران، بهره‌گیری از سایه‌بان‌های متحرک به عنوان یکی از سامانه‌های غیرفعال ساختمانی بوده ‌است که کاربرد گسترده‌ای داشته و می‌توان در معماری امروز از آن به منظور بهبود عملکرد حرارتی فضاهای نیمه‌باز بهره گرفت. در این پژوهش، برای اعتبارسنجی شبیه‌سازی از مقایسه نتایج اندازه‌گیری تجربی استفاده ‌شده است. شبیه‌سازی حرارتی در نرم‌افزار انرژی‌پلاس نسخه 8.9 صورت گرفت. برای شبیه‌سازی، عمق‌ فضای نیمه‌باز، اندازه‌ سطح بازشوی دیوار مجاور فضای نیمه‌باز و ضریب هدایت حرارتی آن در دو نوع بالکن و ایوان، به عنوان متغیر در نظر گرفته ‌شدند و تاثیر الحاق سایه‌بان با لوورهای متحرک و پوشش شیشه‌ای متحرک بر عملکرد حرارتی فضای مجاور بالکن و ایوان بررسی شد. نتایج شبیه‌سازی حاکی از آن بود که در اوقات گرم سال، استفاده از سایه‌بان با لوورهای باز و در اوقات سرد سال، به‌ کار بردن پوسته‌ شیشه‌ای متحرک در جداره‌های باز، سبب ارتقا عملکرد حرارتی فضای مجاور فضای نیمه‌باز است. در اوقات گرم سال، تاثیر سایه‌بان الحاقی بر بهبود عملکرد حرارتی اتاق، با تغییر عمق تفاوت چندانی نمی‌کند ولی در اوقات سرد سال می‌تواند تا 30% بارهای حرارتی را کاهش دهد. در انتها نیز دستورالعملی برای طراحی سایه‌بان‌های متحرک و الحاقی به فضاهای نیمه‌باز ساختمان‌های مسکونی شهر تهران ارائه گردید.

An Analytic Study of the Effect of the Movable Shading Devices Attached to SemiOpen Spaces on the Annual Energy Consumption A Case Study of Residential Buildings in Tehran

One of the most important components of a building that influences physical properties, environmental behavior and responses, and energy consumption is the building envelope. Therefore, accurate decisionmaking in this regard will be of particular importance. Most of the measures taken to reduce energy consumption in buildings are somehow active and mechanical strategies that not only impose the increase of construction cost on employers but also the emission of greenhouse gases in the global environment. Regarding the importance of the role of architects, if the initial decisions in the design process are made based on environmental issues and climatic approach, a considerable saving on cost and energy consumption can be achieved. In the meanwhile, passive systems are the most efficient and clean ways to meet the thermal needs of a building by means of utilizing renewable energy resources such as solar energy, wind power, and so on. In this type of system, fossil fuels and mechanical powers are rarely used. Among the mentioned methods, the element of shading device is one of the most effective solutions that has been widely used in traditional Iranian architecture. This solution has a high potential to be implemented in contemporary architecture as well. Measurements and simulation studies have shown that balcony form and solar protection can significantly affect the thermal comfort of occupants on the balcony as well as in the adjacent room. In this research, one of the existing buildings equipped with a glasscovered balcony was selected as a case study and experimental measurements were taken by two data loggers located in the balcony and adjoining room in order to record the temperature fluctuation. The simulation process was validated by comparing the experimental results. The base case building was modeled in Openstudio software (2.6.0) and Energyplus 8.9 and was then utilized for annual energy simulation. The depth of semiopen space, the window area of the adjoining wall, and its thermal conductivity coefficient in the two types of balconies and porches were considered as the variables. The effect of shading strategies such as movable louver and glass cover on thermal performance was comparatively investigated. The simulation results indicated that the use of an openangle louver as well as a movable glass partition in summer and winter respectively would enhance the thermal performance of the room adjacent to semiopen space. Regarding underconstruction buildings, the effect of using attached shading devices on thermal performance on cold days of a year increases based on the depth of the semiopen space along with window to wall ratio. Although the reduction of the thermal conductivity coefficient of window would make the attached glass partition more effective in the winter, the negative effect has to be considered in the summer. Based on the research findings, this paper concluded in determining a design guideline for the application of a movable attached shading device of semiopen spaces in residential buildings in Tehran metropolitan city.