چكيده فارسي :
پنجره‌ها از نظر انتقال حرارت جز عناصر ضعيف ساختمان محسوب مي‌شوند، اما تابش خورشيد به داخل ساختمان از طريق آن‌ها صورت مي‌گيرد. اگر سطح پنجره به‌درستي انتخاب شود مي‌توان ضعف حرارتي آن را با دريافت انرژي خورشيدي در اوقات سرد سال جبران نمود. تا‌كنون مطالعات بسياري در مورد پنجره‌ها صورت گرفته است كه زمينه‌هاي گوناگوني را شامل مي‌شود از قبيل مشخصات اجرايي پنجره، دريافت نور روز از آن و سطح بهينه پنجره براي دريافت خورشيدي. در اين مقاله سطح بهينه پنجره براي ساختمان‌هاي مسكوني دو شهر اردبيل و تهران با هدف تامين بخشي از نياز گرمايشي ساختمان مطالعه و پيشنهاد شده است. اين بررسي نشان مي‌دهد كه مي‌توان سطح مناسبي براي پنجره‌هاي جنوبي ساختمان‌هاي مسكوني اين دو شهر تعيين كرد به نحوي كه در اوقات سرد سال بخشي از نياز گرمايشي فضاها از تابش خورشيد تامين شود و در اوقات معتدل دماي داخل در حد آسايش باقي بماند.
چكيده لاتين :
Solar gain through windows compensate for their thermal weakness in building envelope. Free solar gains in this way have a significant effect on reducing heating load of the building. Then not only thermal comfort during cold season is obtained, but also the pollution induced by burning fossil fuels will be reduced. One of the simplest passive solar elements is southern window, which is vastly used in traditional and newly built buildings. In contrast to traditional ones, there is no specific size introduced for these windows in modern buildings so that designers may be able to employ them. Many studies have been carried out concerning windows, which cover up various subjects. The conducted researches so far mostly concentrate on specifications of the glass, day lighting from windows and optimal window area for passive solar heating. As Iran is situated in the solar belt of the earth, traditional buildings in our country mostly relied on passive solar heating through windows. In modern buildings, also the same strategy for passive heating of interior spaces can readily be applied. In this paper the optimal window, area for residential buildings of Ardabil (cold climate) and Tehran (hot-arid climate) is studied in order to meet buildingsʹ annual heating energy need partially by solar incidence through windows. The research is carried out using simulation method. Two software programs were used, i.e. EnergyPlus for simulation and calculating hourly inside temperatures and heating load of the building and Ecotect as the graphical interface. A typical room in each abovementioned cities was selected. The room under study had a south orientation. It was supposed that the room was surrounded by spaces having similar temperature and only its south wall with window contributes to heat transfer. There was no heating system in the room in order to see the effect of solar incidence inside. The window area was changed from 5% to 50% of the floor area in five steps. The simulation was carried out considering three different window types and walls: no insulation with single glazing window, insulated south wall with single glazing window and insulated south wall with double glazed window. After selecting the proper window area, two typical residential buildings, one in Ardabil and the other one in Tehran, were simulated considering four different scenarios, first with the building and the window area as it was and then three more scenarios with the optimal window area and the previously mentioned window and wall types. The results showed that by applying the optimal window area, heating load would significantly decrease. When the building is insulated according to Code No. 19 (Energy Conservation in Buildings), to prevent overheat during mild period of the year, the window area should be decreased. Generally speaking, this study indicates that there are optimal window areas for buildings with and without insulation, which by applying them, heating load decreases and energy conservation will be met during cold periods of the year, and also there will be thermal comfort inside within mild seasons.
