Investigation of single-storey residential green roof contribution to buildings energy demand reduction in different climate zones of Iran

ABSTRACT

The share of the building sector accounts for one-third of the total energy consumption in the final energy demand in the world, and they are, indeed, paramount factors for CO₂ emissions. Energy consumption in developing countries piles up to 40%, while this is higher in Iran, and for this reason, energy saving in this sector plays a prominent role. This paper aims to study the effects of using green roofs (GR) on energy consumption and CO₂ emission rate of a sample building in various climate, calls, dry hot, cold, and humid hot, which can correctly represent different climates of Iran. Simulations are done for the entire year using DesignBuilder, which is a popular tool in this regard. Besides, the building construction materials considered in the simulation are the most utilized in Iran, and 15 cm height grass is selected to be used in the roof. Results indicate 6.19%, 2.07%, and 9.45% energy consumption reduction and 238, 100, and 370 kg of emission reduction for Tehran, Tabriz, and Bandar Abbas, respectively. In addition, an economic analysis is conducted to explore the economic viability of green roof implementation. It has been concluded that, according to the tariffs for water and electricity in Iran, the application of green roofs is not economically viable in current economic conditions.

KEYWORDS:

• Green roof
• simulation
• energy saving
• CO₂ emission
• economic analysis

Research highlights

• This paper aims to study the effects of using green roof (GR) on energy consumption and CO₂ emission rate.

• Simulations are done for the entire of a year.

• The building construction materials considered in the simulation are common material in Iran, and 15 cm-hight grass is assumed in the roof.

• Results indicate 6.19, 2.07, and 9.45% energy reduction and 238, 100, and 370 kg emissions reduction for different climate zone respectively.

• According to the water and electricity tariffs in Iran, implementation of green roofs is not economically viable.