Thermal Behavior of Green Roofs In Different Climates

Abstract

Crisis of energy has been turned out into one of the large concerns in societies. One of the most effective solutions to reduce the energy consumption in buildings is green roof. Green roof is used as a passive technique in order to reduce the demand for cooling and heating energy in buildings and improve the quality of their surrounding conditions. In this paper, advantages of using green roofs were assessed and the findings of recent researches about the relationship between green roofs and energy consumption in buildings were reviewed. Results of reviewed studies show that thermal behavior of green roof is subject of different conditions like type and thickness of growing medium, leaf area index and density of vegetation, ceiling temperature transfer coefficient, R-value of roof, and climate of studied region. Finally, results of this study show that green roofs have a positive role in roof thermal behavior in different climates which the rate of their efficiency depends on the climate that they are located in.

Spatio-temporal Analysis of Environmental Criticality: Planned Versus Unplanned Urbanization

“…Several studies have derived LST from Landsat data and proposed algorithms to retrieve LST from Landsat series [39,56,57,59]. Such methods may not be suitable to handle a large number of data sets as it requires high computational efficiency and time-taking.…”

“…In addition, multiple TIR bands of Moderate-resolution Imaging Spectroradiometer (MODIS) sensors provide a good opportunity to capture the UHI phenomenon at various spatial scales [29,30,31,32,33,34,35,36]. The radiant energy emitted directly from the land surface is captured by the sensor in Thermal Infrared (TIR) spectral region that is often used to derive LST [37,38,39,40]. The difference in LST between the urban built-up and non-built-up surface shows the intensity of the UHI effect [41].…”

Passive Design Strategies for Energy Efficient Buildings in the Arabian Desert

“…Green roof is a passive strategy that can be regarded a useful solution in different climates owing to their positive contributions in reducing heat gain/loss, thus saving energy consumption in buildings (Goussous et al, 2015;Silva et al, 2016;Khan and Asif, 2017). However, the performance of the green roof depends mainly on the climatic conditions, the building function, the level of insulation of the building envelope and the type of the green roof itself (Hamid et al, 2015). The original roof was composed of traditional construction layers that included a non-insulated roof with a U-value of 3.437 W/m 2 K. A green roof was implemented on the roofs of the first floor and on the roof of the attached room on the second floor to act as a heat insulator and to take advantage of its ability to lower air temperatures and minimise the airconditioning system requirements.…”