Scientists have discovered a new method to cool buildings, which could help reduce the heavy reliance on air conditioning, especially in hot climates.
This innovative approach, developed by researchers at The University of Texas at Austin, promises to lower indoor temperatures by 0.7 degrees Celsius without using energy-intensive air conditioners.
The study, published in the Journal of Architectural Engineering, focuses on natural ventilation techniques.
The researchers applied these methods to a prototype building in the United Arab Emirates (UAE), a region where air conditioning is a necessity year-round.
“The prototype building was real, and several tests have been run on it,” says Vittorino Belpoliti, an associate professor of green building design and energy technologies at Sharjah University and the study’s lead author.
To assess the effectiveness of these natural ventilation techniques, the scientists compared predicted results from software simulations with real measurements from the building. They examined how well the building could control and dissipate heat, a process known as passive cooling.
In the study, the researchers used Computational Fluid Dynamics (CFD) to analyze the contribution of natural ventilation in cooling the building. The results showed that natural ventilation techniques, such as cross-ventilation, chimney effect, and wind catchers (locally known as Barjeel), effectively reduced the building’s indoor temperature by 0.7 degrees Celsius.
The Barjeel, or wind tower, is an ancient method of catching breezes to cool buildings, once common in the UAE and the Gulf region before the advent of modern air conditioning. Although natural ventilation alone cannot replace air conditioning in the UAE, it can significantly reduce its use during milder seasons, according to Belpoliti.
The UAE’s buildings, typically made from reinforced concrete, steel, and large glass panes, lack insulation and are not designed for passive cooling. However, the study notes that structures allowing natural ventilation, like Barjeel, can be added to private homes. This addition requires cooperation from occupants to operate the openings of their homes.
This study is part of a research and education program called Know-Howse, which aims to increase awareness of environmentally friendly building practices. The program’s goal is to design prototype houses that combine occupant comfort with environmental goals, such as reducing land use and resource consumption.
Know-Howse includes a multidisciplinary team of students and researchers from the University of Sharjah and Italy’s University of Ferrara and its research arm, Architettura>Energia Research Center.
“The KNOW HOWse was not just an energy-efficient project, it was a whole educational program: a house that trained the occupant to behave with more awareness of energy, water, and other finite resources,” says Belpoliti.
The UAE has one of the highest electricity consumption rates in the world, with nearly 70 percent of it used for air conditioning. Any reduction in indoor temperature through passive cooling can significantly impact energy demand and carbon emissions.
While passive cooling alone cannot fully replace air conditioning in hot climates like the UAE, it can greatly contribute to reducing its use, leading to more sustainable building practices. “Natural ventilation cannot replace air conditioning, but it can greatly contribute to limiting its use towards achieving more sustainable buildings for hot climates,” Belpoliti emphasizes.
This innovative approach to natural cooling not only promises to reduce energy consumption but also offers a more sustainable way to manage indoor temperatures, paving the way for greener building practices in hot climates around the world.
