بررسي تاثير سايبان و عايق گرمايي بر بار سرمايشي ساختمان اداري در سه اقليم گرم و مرطوب، معتدل و سرد

Evaluation of Window overhang and External wall thermal Conductivity reduction Effect On office Cooling load in 3 Climates Hot and Humidity, Mild and Cold

امروزه براي فراهم كردن آﺳﺎﻳﺶ در ﺳﺎﺧﺘﻤﺎنﻫﺎ انرژي زيادي صرف مي‌شود لذا ضروريست راهكار مناسب جهت كاهش مصرف ارايه گردد. ﻳﻜﻲ از راهﻫﺎي محاسبه انرژي مصرفي ساختمان، ﺑﺮﻧﺎﻣـه­ﻫـﺎي ﺷﺒﻴﻪ‌ﺳﺎز مانند انرژي‌پلاس(1) و ديزاين­بيلدر(2) ﻣﻲﺑﺎﺷﺪ. در اين مقاله انرژي مصرفي بار سرمايش يك مدل واقعي با نرم‌افزار ديزاين­بيلدر در سه شهر اهواز، تهران و تبريز بر اساس دو راهبرد مختلف شبيه‌سازي شده و تاثيرات آنها بر مصرف انرژي در روز 1 جولاي مورد بررسي قرار گرفته است. راهبرد اول استفاده از معادله انتقال گرماي تابشي و كاهش سطح مقطع تابيده شده ساختمان با بكارگيري سايبان با عمق‌هاي مختلف (6 حالت) است و راهبرد دوم بكارگيري معادله فوريه مي‌باشد كه با استفاده از عايق گرمايي با ضخامت‌هاي متفاوت (5 حالت) ميزان كاهش شار گرمايي ساختمان محاسبه شده است. نتايج نشان داد براي شهر اهواز و تهران راهبرد دوم بر راهبرد اول ارجحيت دارد ولي در شهر تبريز اختلاف دو راهبرد كم مي­ باشد. همچنين نتايج شهر اهواز نشان داد كاهش مصرف انرژي با استفاده از سايبان غالبا صحيح نمي‌باشد و كاربرد عايق گرمايي با ضخامت يك سانتيمتر تاثير خوبي در كاهش مصرف انرژي دارد.

In today’s world too much energy is consumed to provide comfort conditions inside the buildings and this makes it necessary to estimate the energy consumption and recommend appropriate strategy to reduce it. One way of calculating the amount of energy consumption for providing comfort conditions is to employ simulated programs such as EnergyPlus and DesignBuilder. In this paper one authentic case study has been chosen and by applying DesignBuilder program, the amount of energy consumption for its cooling condition on 1st of July in three different cities based on two different strategies has been simulated and their effects on electric energy consumption have been compared. The first strategy is to employ the equation of estimating heat transfer via solar radiation and using overhang shades (6 different thicknesses) to reduce the area of the building exposed to solar radiation and reducing the heat gained from it. The second one is to apply the equations of Fourier's law in which the amount of reduction in heat transferred to the building by utilizing heat insulations in 5 different thicknesses is calculated. The results showed that the second strategy has much more superiority over the first one considering in Ahvaz and Tehran cities, but for Tabriz, the difference between two strategies is less. Furthermore the results obtained in Ahvaz showed that our conception of reducing the energy consumption by employing overhang shades is not always right. an‎d employing heat insulation even by the thickness of one centimeter is more effective.