Transient Thermal Model for Energy Saving for Buildings Using a Green Roof Technique

摘要

The present study is dealing with a mathematical modeling and thermal analyses of a green roof above a house with an area of 100 m~2. The house located in Taif city, Saudi Arabia. The developed model included sub-models for: canopy of vegetation, ground layer, concrete layer, and the cooling load of the house. The model considered sensible and latent heats for foliages as well as the ground layer. Variation of different temperatures through the ground and concrete layers are obtained using finite difference technique with new derivations for some nodes which are not available in the published works. A realistic method including the mass and orientation of the walls and windows of the house are used to calculate the cooling load. At the same time, a similar house with the same size without green roof is proposed and studied to compare the effect of the presence of the developed green roof. The simulation results showed that the maximum temperature of the house with a green roof is lower by about 10°C than that for the house without green roof in July month.