Designing and testing the applicability of a natural green ventilation building block in an Egyptian Climatic zone using waste materials
|
Full Text |
Pdf
|
|
Author |
A. M. Abdel-Wahab, Ayman Mahmoud Hesham Elalfy, Allam M. E., Garas G. L., Ashraf Mansour Habib Mansour, Amr Ahmed Elfeky and Mahmoud A. El-Bayoumi
|
|
e-ISSN |
1819-6608 |
|
On Pages
|
759-771
|
|
Volume No. |
18
|
|
Issue No. |
07
|
|
Issue Date |
May 30, 2023
|
|
DOI |
https://doi.org/10.59018/0423103
|
|
Keywords |
natural ventilation in buildings, ventilation blocks, marble and granite waste materials, Egyptian climatic zones, fluid dynamics computer simulation.
|
Abstract
Natural ventilation is one of the ways used to enhance building spaces' indoor air quality, especially after the COVID-19 pandemic. It also saves energy by utilizing natural wind forces to provide internal building spaces with fresh air instead of energy-consuming mechanical systems. For a multiple-floor building, adding external wall ventilation blocks can improve natural cross ventilation by catching and directing fresh air from the external prevailing wind into its internal spaces. This research aimed to enhance the building's natural ventilation by using environmentally friendly blocks. This was done by designing a green block using marble and granite waste materials as a partial substitute for conventional materials in the block. Styrofoam beads were added to the block’s mixture to reduce its weight. The block’s shape was designed to direct fresh air through building side walls by the use of natural wind pressure. The block was developed from the initial shape of the standard hollow block to a block with a wind catcher. Ventilation block shape simulations were done using (ANSYS fluent) computational fluid dynamics (CFD) software to determine the best inlet angle, catcher angle, and catcher length. The study revealed that by increasing the block inlet angle more than 45°, the block outlet air velocity starts to decrease due to the flow separation in the front part of the block inlet. The catcher angle ranged from 65° to 85°, and the catcher’s ability to redirect the airflow is decreased at a catcher angle greater than 85°. The best nondimensional catcher length-to-block length ratio (height /length) h/L was 0.625. Substitution of 5% of cement by granite in the presence of 0.15 Kg of Styrofoam (C5G) produced a lightweight green ventilation block of weight 19.3 kg. Whereas, the substitution of 15% of sand for marble in the presence of 1 Kg of Styrofoam (S15M) produced a lightweight green ventilation block of weight 15.9 kg. The produced block was tested in a building located in New Cairo City (a region currently having a tremendous increase in the building construction sector) as a study sample representing one of the Egyptian Climatic zones. The research concluded that it is preferred to allocate the building corners towards the prevailing wind direction to prevent airflow separation and to magnify the quantities of air along the building sides.
Back