نوع مقاله : علمی - پژوهشی

نویسنده

مربی دانشکدة معماری و شهرسازی دانشگاه شهید بهشتی

چکیده

مصرف انرژى یکى از مهم ترین شاخص ها در جهان امروزى است. به این موضوع مى توان از زوایاى متفاوتى نگریست. از طرفى مصرف بیشتر انرژى به معناى تولید بیشتر و  یا صنعتى بودن کشورها بوده و از طرفى دیگر موجب آلودگى بیشتر محیط زیست خواهد شد . افزایش گازهاى گلخانه اى، گرم شدن کرة زمین، آب شدن یخ هاى قطبى، و صدمه دیدن لایة ازن از عوارض آلودگى محیط زیست هستند. همچنین افزایش هزینه هاى انرژى ، بار مالى بیشترى را بر کشورها تحمیل می کند. یکى از مصر ف کنندگان عمدة انرژى ساختمان ها هستند. در این پژوهش نقش رنگ در کاهش مصرف انرژى مطالعه میشود و با آزمایشات انجام شده محقق می گردد که تغییر رنگ بام (سقف) حدود 17 ٪ به خنک شدن داخل ساختمان ها و درنتیجه کاهش مصرف انرژى منجر میگردد. براى کاهش مصرف انرژى در ساختمان ها روش هاى متفاوتى را مى توان به کار گرفت، از تغییر زاویة جهت گیرى ساختمان ها تا عایق کارى و یا تغییر مصالح، لکن فعالیت تغییر رنگ در مورد ساختمان هاى موجود به سادگى قابل حصول و با هزینه اى بسیار کم و در برخى موارد بدون هزینة اضافى قابل دستیابى است.

کلیدواژه‌ها

عنوان مقاله [English]

The Cool Roof Experimenting with Change of Color to Cool the Roof

نویسنده [English]

  • Farshad Razmgah

Lecturer, Faculty of Architecture and Urban Planning, Shahid Beheshti University

چکیده [English]

In Iran, some 22 percent of the building energy dissipates through the roof. In the hot arid parts of the country, most of this energy is used for cooling rather than heating. There are several methods for reducing this energy loss. Insulation is one popular method throughout the world. A more effective method is to reduce the energy penetrating the building by means of cooling the roof. There are three main techniques for obtaining a “cool roof”. In the first method, heat loads are reduced by lightening the color of the roof, hence increasing its albedo. In the second method, the “green roof”, the roof is suffused with vegetation, which is more expensive and technically complicated. In the third method, the roof is sprinkled with water. In this method, a significant amount of water is wasted, however. Because of its inexpensiveness and simplicity, the first method was chosen for an experiment, in which part of a dark green roof was repainted with brilliant light green. The daily summer temperatures were then measured on an hourly basis and compared with the shaded areas of the roof as well as areas covered by plants. The results indicated that the repainted areas were about 17 percent cooler.

  1. منابع و مآخذ
  2. نمازیان، على. اصول استفاده از تابش خورشید در طراحى معمارى، دانشگاه
  3. . شهید بهشتى، 1389
  4. Akbari, H. & S.J. Konopacki. “The Impact of Reflectivity
  5. and Emissivity of Roofs on Building Cooling and Heating
  6. Use”, in Thermal Performance of the Exterior Envelopes of
  7. Buildings,VII, proceedings of ASHRAE THERM VIII, FL, Dec
  8. ASHRAE 90.2: American Society of Heating, Refrigerating
  9. and Air Conditioning Engineers.
  10. CRRC’s Role in Green Buiding. “Features and Benefits of
  11. Cool Roofs: The Cool Roof Rating Council Program”, in
  12. Journal of Green Building, Vol. 3, No. 2 (2008).
  13. Gallo,C. & M. Sala & A.A.M. Sayigh. Architecture: Comfort
  14. and Energy, Elsevier, 1988.
  15. Hildebrandt, E. & W. Bos and R. Moore. “Assessing the
  16. Impacts of White Roofs on Building Energy Loads”, in
  17. ASHRAE Technical Data Bulletin, American Society of
  18. Heating, Refrigerating and Air-Conditioning Engineers,
  19. Atlanta, GA, vol 14, no 2 (1998), pp. 28–36.
  20. Konopacki, S. and H. Akbari. “Measured Energy Savings
  21. and Demand Reduction from a Reflective Roof Membrane
  22. on a Large Retail Store in Austin”, LBNL-47149, Lawence
  23. Berkeley National Laboratory, Berkeley, CA, 2001.
  24. LBNL: Lawrence Berkeley National Lab. A U.S. Department
  25. of Energy Office of Science National Lab that Brings
  26. Science Solutions to the World.
  27. Levinson, Ronen & Hashem Akbari. “Evolution of Cool-Roof
  28. Standards in the US Advances” in Building Energy Research,
  29. Vol. 2, 2008.
  30. Levinson, R. and H. Akbari, “Potential Benefits of Cool Roofs
  31. on Commercial Buildings: Conserving Energy, Saving
  32. Money, and Reducing Emission of Greenhouse Gases and
  33. Air Pollutants”, in Energy Efficiency, 2009. Page 78.
  34. Sayigh, Ali. “Introduction”, in Gallo,C. & M. Sala & A.A.M.
  35. Sayigh. Architecture: Comfort and Energy, Pergamon, 1988,
  36. p. 1.
  37. Wong, N.H. & P.Y. Tan. & Y. Chen. “Study of Thermal
  38. Performance of Extensive Rooftop Greenery Systems in the
  39. Tropical Climate”, in Build Environ, 42 (2007), pp. 25–54.
  40. Young, R. “Cool Roofs: Light –Colored Coverings Reflect
  41. Energy Savings and Environmental Benefits”, in Building
  42. Design and Construction, Vol. 39, No. 2 (1998), pp. 62-64.
  43. WWW.COOLROOFTOOLKIT.org