Novel energy efficient integration of chimney ventilation, liquid desiccant dehumidification, and evaporative cooling for humid climates

The chimney effect for driving passively building ventilation is effective in dry and moderate climates to introduce cool fresh air into the space. However, its application in hot humid climates is limited due to the high energy demands associated with dehumidifying and cooling outdoor air. Thus, a...

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Main Authors: Omar Allahham, Kamel Ghali, Nesreen Ghaddar
Format: Article
Language:English
Published: Elsevier 2024-10-01
Series:Energy Conversion and Management: X
Subjects:
Online Access:http://www.sciencedirect.com/science/article/pii/S2590174524002332
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author Omar Allahham
Kamel Ghali
Nesreen Ghaddar
author_facet Omar Allahham
Kamel Ghali
Nesreen Ghaddar
author_sort Omar Allahham
collection DOAJ
description The chimney effect for driving passively building ventilation is effective in dry and moderate climates to introduce cool fresh air into the space. However, its application in hot humid climates is limited due to the high energy demands associated with dehumidifying and cooling outdoor air. Thus, a novel energy-efficient assistive system is proposed integrating a chimney-driven ventilation with liquid desiccant dehumidification membrane loop and indirect evaporative cooling. This system leverages natural buoyancy to supply ventilation airflow and uses potassium formate loops through semi-permeable membranes for effective dehumidification. The objective is to dehumidify and cool the induced outdoor air to the room conditions of 24°C and relative humidity between 40% and 60% at minimal energy consumption. Mathematical models were developed to simulate the heat and mass transfer processes in the air and liquid desiccant flows within the system components. The system was sized, and its operation was optimized using an advanced machine learning-genetic algorithm model for a typical office space in Beirut. During the summer, the chimney air flowrate ranged from 45L/s to 48L/s, and it was delivered at the target room conditions. The system saved around 350kWh of electrical energy during the summer months due to elimination of the need to treat ventilation air by room cooling system. This was equivalent to the total energy required to handle the ventilation load during the summer season and resulted in a saving of $50/month in the case study.
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spelling doaj-art-d9aa5b35b2e945a5a9e36a83e2bee5e72025-08-20T01:57:52ZengElsevierEnergy Conversion and Management: X2590-17452024-10-012410075510.1016/j.ecmx.2024.100755Novel energy efficient integration of chimney ventilation, liquid desiccant dehumidification, and evaporative cooling for humid climatesOmar Allahham0Kamel Ghali1Nesreen Ghaddar2Department of Mechanical Engineering, American University of Beirut, Beirut, LebanonDepartment of Mechanical and Nuclear Engineering, Kansas State University, Kansas, USADepartment of Mechanical Engineering, American University of Beirut, Beirut, Lebanon; Corresponding author.The chimney effect for driving passively building ventilation is effective in dry and moderate climates to introduce cool fresh air into the space. However, its application in hot humid climates is limited due to the high energy demands associated with dehumidifying and cooling outdoor air. Thus, a novel energy-efficient assistive system is proposed integrating a chimney-driven ventilation with liquid desiccant dehumidification membrane loop and indirect evaporative cooling. This system leverages natural buoyancy to supply ventilation airflow and uses potassium formate loops through semi-permeable membranes for effective dehumidification. The objective is to dehumidify and cool the induced outdoor air to the room conditions of 24°C and relative humidity between 40% and 60% at minimal energy consumption. Mathematical models were developed to simulate the heat and mass transfer processes in the air and liquid desiccant flows within the system components. The system was sized, and its operation was optimized using an advanced machine learning-genetic algorithm model for a typical office space in Beirut. During the summer, the chimney air flowrate ranged from 45L/s to 48L/s, and it was delivered at the target room conditions. The system saved around 350kWh of electrical energy during the summer months due to elimination of the need to treat ventilation air by room cooling system. This was equivalent to the total energy required to handle the ventilation load during the summer season and resulted in a saving of $50/month in the case study.http://www.sciencedirect.com/science/article/pii/S2590174524002332Energy efficiencyPassive ventilationChimney effectLiquid desiccant dehumidificationIndirect evaporative coolingAdsorption
spellingShingle Omar Allahham
Kamel Ghali
Nesreen Ghaddar
Novel energy efficient integration of chimney ventilation, liquid desiccant dehumidification, and evaporative cooling for humid climates
Energy Conversion and Management: X
Energy efficiency
Passive ventilation
Chimney effect
Liquid desiccant dehumidification
Indirect evaporative cooling
Adsorption
title Novel energy efficient integration of chimney ventilation, liquid desiccant dehumidification, and evaporative cooling for humid climates
title_full Novel energy efficient integration of chimney ventilation, liquid desiccant dehumidification, and evaporative cooling for humid climates
title_fullStr Novel energy efficient integration of chimney ventilation, liquid desiccant dehumidification, and evaporative cooling for humid climates
title_full_unstemmed Novel energy efficient integration of chimney ventilation, liquid desiccant dehumidification, and evaporative cooling for humid climates
title_short Novel energy efficient integration of chimney ventilation, liquid desiccant dehumidification, and evaporative cooling for humid climates
title_sort novel energy efficient integration of chimney ventilation liquid desiccant dehumidification and evaporative cooling for humid climates
topic Energy efficiency
Passive ventilation
Chimney effect
Liquid desiccant dehumidification
Indirect evaporative cooling
Adsorption
url http://www.sciencedirect.com/science/article/pii/S2590174524002332
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AT nesreenghaddar novelenergyefficientintegrationofchimneyventilationliquiddesiccantdehumidificationandevaporativecoolingforhumidclimates