Keeping Cool Without AC: A Shift in Perspective?
Updated: Oct 25
Globally, air conditioning has become essential during hot summers. But ironically, experts say it exacerbates the extreme temperatures so we end up needing it even more. Luckily, fresh and creative cooling ideas are popping up that mix old-school tricks with futuristic tech and take cues from nature. Let's dive into these new approaches.
Air conditioning is convenient and essential, and all we have to do is press a button. However, its drawbacks, including health concerns, high energy bills, and affordability issues, are more and more well-known. Traditional systems contribute to climate change by leaking F-gases and consuming significant electricity, linking them to global warming and extreme weather. Good news is, innovative initiatives worldwide are offering alternative solutions by learning from the past and nature and taking a huge step into the future.
New Cooling Initiatives
For instance, there are cities which are adopting sustainable cooling initiatives as they grow, focussing on building designs with cooling features and broader solutions like green roofs and walls. These methods reduce city heat and lessen reliance on air conditioners. Take the India Cooling Action Plan (ICAP), which provides guidance for cooling in hot climates, highlighting urban planning, building design, and cleaner refrigerants. There are also experts in the field of holistic and passive cooling, such as Dr. Radhika Khosla, who are working on developing frameworks that emphasise street trees, green facades, and roofs.
Ancient Passive Cooling around the World
For centuries, people allover the world have been using what's known as passive cooling techniques. Take Indian Stepwells, for example. These are beautifully designed building structures that help with water conservation, cooling, social gatherings, and agriculture; just by being there. Thanks to their depth and thick walls, these buildings stay about 5 to 8 degrees Celcius cooler than the air outside of them. They've been around for 1,500 years, and some are still doing their thing today, like at the Pearl Academy of Fashion in Rajasthan, where it's even a comfy 20 degrees cooler inside than out. Experts believe that bringing Indian Stepwells back to life could even help with today's extreme droughts and water shortages.
Over in China, Skywells—also called 'air wells' and 'wind catchers'—have been a key part of Chinese architecture for ages. No fancy tech involved here! They naturally cool and ventilate spaces, helping people escape the scorching heat. They work using the 'chimney effect' to move air around. Nowadays, modern architects are bringing these designs back for eco-friendly cooling and collecting rainwater.
Then there are wind catchers, which are these tall structures that naturally cool down buildings by bringing in breezes and pushing out the warm air. They started in Egypt about 3,300 years ago and are mostly seen in Iran, Egypt, and the Middle East. In Australia, they're known as 'wind towers'.
There are also special perforated or ventilated facades that help with passive cooling by boosting airflow and keeping out intense heat. Taking cues from traditional designs like the Middle Eastern 'Mashrabiya' and South Asian 'Jali,' these facades are making a comeback allover the world.
And what about the intriguing mud-brick beehive houses. These ancient, cone-shaped buildings can be found in Turkey and northern Syria. Going back about 3,000 years, they are a great example of old-school design that keeps things cool in the summer and warm in the winter even today. Research in Harran shows that these simple structured houses stay comfy inside even when it's over 40°C outside, all without any air conditioning.
Traditional Passive Cooling Today
Today, people allover the world are increasingly integrating past lessons with modern techniques, utilising natural elements like breezes and intelligent designs to maintain cool buildings. This passive cooling approach is becoming popular as we reconsider building methods, reducing dependence on air conditioning.
Take, for example, 'tiny houses' and prefabricated homes—popular for their efficient construction methods and low energy requirements, with materials like CLT (cross-laminated timber) used for passive thermal insulation—or even entire cities that are nowadays being built entirely out of wood.
According to the European Environment Agency, well-designed buildings can remain cool during heatwaves. Notably, some desert homes maintain comfort without air conditioning, and studies show Moroccan buildings with local materials stay 5°C cooler than concrete ones. Passive cooling is cost-effective, simple, and maintains fresh indoor air without energy costs.
Nature Inspired Systems
Some innovative cooling specialists are even developing new technology inspired by nature's cooling methods. By studying termite mounds and marine coral for airflow and ventilation, they apply these concepts to keep buildings cool. Nature-inspired cooling systems in skyscrapers worldwide are reducing energy use and emissions by mimicking natural designs and plant-based methods.
Advancing into the Future
But let's not worry, air conditioning isn't going anywhere. People are coming up with cool new ideas for ACs that use more efficient and eco-friendly refrigerants. Plus, there are some neat alternatives like the urban cooling bamboo system, which uses warm air, water, and bamboo to keep things cool during heatwaves. Geothermal cooling systems are another option, moving heat from buildings into the ground with renewable energy. Then there are swamp coolers, or evaporative coolers, which cool things down by evaporating water in dry places. Radiant cooling systems, which you see in commercial buildings and European designs, use chilled water in panels or tubes to cool surfaces and people with less energy, and they're becoming a hit in North America.
Meanwhile, cutting-edge materials and coatings are also being created to cool buildings without needing electricity or refrigerants. Cool ideas like 'photoluminescent facades' bounce sunlight away to keep surfaces cooler, as explored in the Cold Surface project. According to experts, projects like these can help reduce the energy demand for cooling by 5% to 10%, while also mitigating the 'urban heat island effect'—a phenomenon where cities become even hotter due to the use of numerous air conditioning units.
Researchers are even looking into special wires that could provide a more efficient, chemical-free alternative to traditional air conditioning. Even though these technologies are still in the early stages, they are said to look pretty promising.
Keeping Cool without AC: A Shift in our Cooling Reality?
What's the next move for staying cool without relying on traditional AC? Some promising numbers show that alternative cooling methods really work. In China, green roofs have managed to lower the average land surface temperatures by 0.91 degrees C, highlighting how older passive cooling techniques are making a comeback in the age of modern appliances.
The Kigali Amendment and natural refrigerants like R-290 (propane) are paving the way for climate-friendly cooling. People are encouraged to pick units with greener refrigerants, like R-32 or R-290, which are getting easier to find and more budget-friendly.
"A shift in perspective comes from recognising that we have many ways to stay cool and achieve thermal comfort," Dr Khosla told Perspective Living, "ways that don’t require air conditioning. Such passive solutions, including shading and ventilation, have been available to us for generations. They allow for a much more sustainable cooling, energy and climate future."
"A shift in perspective comes from recognising that we have many ways to stay cool and achieve thermal comfort."
The Big Picture: The Dark Side?
As more people crank up the air conditioning, experts are increasingly highlighting its impact on the extreme climate. It's a bit of a cycle: more AC use leads to higher temperatures, which then prompts even more AC use. In fact, authorities such as the US Environmental Protection Agency (EPA) areworking to phase out harmful refrigerants like HFCs. Experts like Fatih Birol from the International Energy Agency (IEA) and Dr. Radhika Khosla from the University of Oxford stress the need to address the growing demand for air conditioning and find greener ways to stay cool. The IEA report The Future of Cooling highlights that changing how we cool our buildings is a big opportunity to reduce environmental damage.
Why Don't We Know about This?
Realistically, do any of us know exactly how AC units and heat pumps impact the environment? Experts talk about the "Invisible Leak" Paradox, where hidden leaks make us think there's no harm. There's also the "Green Halo" of Heat Pumps, which are sold as eco-friendly but actually have harmful refrigerants. Then there's the "Air Conditioning Paradox," where AC is viewed as a necessity rather than a contributor to climate change. Plus, there hasn't been much focus on policies for cooling, which has slowed down action.
