Wind catcher in Iran — *Source:* *Behnam Ramezani*

As the world has gone through an industrial revolution and introduced many modern conveniences to make the lives of people better across the world, it has had to pay a large cost in the currency of power and energy.

Modern urbanization has driven the demand for power exponentially, leading to the need for more efficient power plants that produce a vast amount of electricity to power all of these urban centers.

Air conditioners take up approximately 10% of energy requirements in cities, making them one of the major contributors to global carbon emissions.

The need for cooling has grown massively as buildings have gotten bigger and glassier. Most tall structures in cities are almost entirely wrapped in glass. This creates a strong heating effect inside, increasing the load on the cooling system.

However, before urbanization and modern conveniences, our ancestors survived hot, harsh climates with their native architectural practices and never had the need for air conditioning units. The technology they had back then may have seemed primitive compared to recent times, but it was, at the very least, functional, environmentally friendly, and efficient in its purpose.

In this blog, we will explore the use of Wind Catchers in the Middle East and how they kept people in dry, harsh deserts cool.

What is a wind catcher?

A wind catcher is a tower that is built to catch the air from a breeze higher than ground level and redirect to the inside of a space to naturally ventilate it’s air and cool the space.

It works by creating a pressure difference and taking advantageof varying internal and external temperatures, also known as the stack effect.

What is stack effect?

Stack effect: Stack effect is air movement caused by thermal differences. Higher-temperature air is less dense than cooler air. As the warmer air rises, it creates a pressure difference, with lower pressure below and higher pressure above

Stack effect diagram — *Source: ResearchGate*

Stack effect is commonly observed in modern construction where air enters a structure from one side and is redirected to the other side allowing for a soft breeze to take place and allow old warmer air to flow out and allow fresher air inside constantly.

Mostly used in the middle east to fight the hot dry climates as well in the asian subcontinent to combat humidity and stagnant air.

Examples of Wind Catchers

Dowlat Abad Gardens | Yazd, Iran.

In the heart of Yazd, Iran, you'll find two remarkable historical gardens with an extraordinary feature that stands tall - windcatchers. These adobe-made structures are both UNESCO World Heritage Sites, captivating visitors with their architectural magnificence.

Dowlatabad Garden boasts the world's tallest adobe windcatcher, soaring to an impressive height of 33.8 meters (110 ft). This incredible structure is a testament to human ingenuity in harnessing natural forces for cooling and ventilation.

Just a stone's throw away, the second garden, with its half-collapsed windcatcher, narrates a story of historical preservation and architectural restoration. Both gardens reflect the vital role of windcatchers in cooling and climate control, an ingenious tradition passed down through generations.

Qatar University campus | Doha, Qatar.

Designed by Architect Kamal El Kefrawi in 1973, The complete campus was constructed using precast cladding and low-rise concrete modules, resulting in a intricate pattern of octagonal shapes. Where every instance of an octogan features a wind catcher on its roof, providing cool fresh air to every space within the building.

Perched on a wadi's edge, El Kafrawi's design combines traditional elements like numerous wind catchers and Mashrabiyyas for aesthetics and comfort. Courtyards, shaded by tree canopies and screens, serve as communal spaces, featuring vegetation and fountains amidst octagonal modules. The rooflights also display calligraphy panels by Egyptian calligrapher Ahmed Mustafa.

Wind catchers of Qatar University — *Source:* *SceneHome*

What are the benefits of a windcatcher?

Natural Ventilation:

One of the key benefits of a windcatcher is its ability to provide natural ventilation. These ingenious architectural features utilize wind to circulate air within a building, creating a continuous flow of fresh, outside air. By harnessing the power of the wind, windcatchers can help maintain a comfortable and healthy indoor environment, making them a sustainable and eco-friendly choice for cooling and ventilation.

Constant Fresh Air:

Windcatchers ensure a steady supply of fresh air. Unlike some mechanical ventilation systems, which may recirculate stale air, windcatchers bring in a continuous stream of outdoor air. This constant inflow of fresh air can contribute to improved indoor air quality, making spaces more pleasant and healthier for occupants.

Low Maintenance Costs:

Windcatchers are known for their simplicity and durability, resulting in lower maintenance costs compared to complex mechanical systems. With fewer components and minimal reliance on technology, windcatchers are not only cost-effective to install but also cost-efficient to maintain over time. This makes them a practical and sustainable solution for natural cooling and ventilation.

Silent Compared to Air Conditioners:

Windcatchers offer the added benefit of being virtually silent. Unlike air conditioners, which can generate noisy humming or buzzing sounds, windcatchers operate quietly. This silent operation creates a peaceful and serene indoor atmosphere, ideal for those who prefer a tranquil and noise-free environment.

No Electricity Requirements:

One of the most remarkable advantages of windcatchers is their independence from electricity. They do not rely on power sources to operate, making them an energy-efficient and environmentally friendly option. By utilizing wind and natural principles, windcatchers reduce the carbon footprint and contribute to sustainable, off-grid cooling and ventilation solutions.

Problems with Windcatchers

Low Wind Regions

Wind catchers are highly effective in regions with ample wind flow. However, in areas with low-speed winds, they may not function as efficiently.

This limitation can pose challenges for achieving effective natural ventilation and cooling in such regions.

Dust and Pest Ingress

Wind catchers provide a pathway for outside air to enter indoor spaces. While this is advantageous for ventilation, it can also allow dust particles and pest insects to enter.

Keeping the wind catcher openings clean and preventing the entry of unwanted guests can be a maintenance challenge.

Limited Cooling Energy Savings

Wind catchers are renowned for their ability to cool indoor spaces naturally. However, the cooling effect they provide is limited due to the low thermal capacity of the materials used in their construction.

As a result, on extremely hot days, the cooling energy saved by wind catchers may not be sufficient to maintain a comfortable indoor temperature.

Wind Escape

While wind catchers are designed to channel and direct wind into buildings, some of the trapped wind may escape through other openings, such as windows or doors, and fail to enter the building. This can affect the overall efficiency of wind catchers in providing natural ventilation.

Proper design and maintenance are essential to address this issue and ensure effective cooling.

However, these challenges can be effectively addressed through thoughtful design and construction practices, minimizing their potential drawbacks.

In conclusion, wind catchers represent a remarkable blend of ancient wisdom and modern sustainability.

While they come with their own set of limitations, such as wind dependency and potential intrusions, the benefits they offer, from natural ventilation to low maintenance, are undeniable.

By harnessing the power of intelligent design and construction practices, we can capitalize on wind catchers' strengths and minimize their weaknesses.

Their silent, electricity-independent operation makes them an eco-friendly alternative that not only cools indoor spaces but also contributes to a greener, more sustainable future.

So, whether you're captivated by their history or intrigued by their potential, wind catchers remain an architectural marvel worthy of attention and appreciation and worth incorporating into your next architectural project.

Solving the ventilation problem: Windcatchers