We enjoy a sunny days, but we certainly don’t like it when it’s too hot. According to Washington Post report, the world is about to install 700 million more air conditioners. While we are cooling down our own little housing environment, we are making the planet hotter. Which in turn makes us more reliant on air conditioning. And the cycle continues. But now, we might just have a solution.
Progress across the World.
Scientists develop a new material highly effective in reflecting heat.
A team of scientists at the University of Colorado Boulder recently announced a new material. This plastic roll highly effective in reflecting heat. It even works when the sun sets and without any additional electricity. The heat reflector is made of cheap ingredients that can easily be mass produced. It is capable to bounce 96 percent of sunlight that hit the material, allowing what is under the material to cool off effectively. It is not much thicker than aluminium foil, which means it can be applied on windows and rooftops to cool down houses. Even on top of solar panels, which will help the panels harvest one to two percent of energy, “that makes a big difference in scale” Said Yin, one of the creators of this new material.
Scientists develop clothing which cools the body.
Now researchers at Stanford University in the US have developed a low-cost, plastic-based textile that, if woven into clothing allows body heat to escape while preventing light and heat penetrating.
Describing their work in the journal Science, the researchers suggest that the new fabric could help keep people cool in hot climates without air conditioning.
Dr Yi Cui, an associate professor of materials science and engineering and of photon science at Stanford, said: “If you can cool the person rather than the building where they work or live, that will save energy.”
The new material – dubbed nanoPE – is made of a special kind of cling film which has tiny holes, one hundred times smaller than a human hair which allow infrared light to pass through, but cause visible light – which has a different wavelength – to bounce off. The material also allows perspiration to evaporate through the material.
Currently cotton only allows 1.5 per cent of infra-red waves to pass through but the new material lets 96 per cent of waves out, making the wearer feel nearly 4 degrees Fahrenheit cooler than if they wore normal cotton clothing.
The researchers said the difference means that a person dressed in their new material might feel less inclined to turn on a fan or air conditioner.
At normal skin temperatures of 93F (34C) the human body emits mid-infrared (IR) radiation in the wavelength range that partially overlaps with that of the visible light spectrum, which means that any cloth which blocks visible light, also traps in body heat.
“Forty to 60 per cent of our body heat is dissipated as infrared radiation when we are sitting in an office,” said Prof Shanhui Fan of Stanford.
“But until now there has been little or no research on designing the thermal radiation characteristics of textiles. Wearing anything traps some heat and makes the skin warmer.
“If dissipating thermal radiation were our only concern, then it would be best to wear nothing.”
The team is now experimenting with producing bright colours and testing whether it could be used in tents, buildings and vehicles.
Asia architects use green solutions to cool buildings
T3 Architecture Asia, which has offices in Vietnam and France, specializes in back-to-basics “bioclimatic architecture“, which it says could make energy-guzzling AC units redundant.
By harnessing the local topography, climate, and vegetation, as well as cleverly manipulating a building’s orientation, the firm can naturally create a comfortable indoor climate.
“It is crucial for all new building designs in cities to encompass bioclimatic architectural features,” Myles McCarthy, director of implementation at the Carbon Trust consultancy and research firm, tells CNN.
“As demands in Asian cities for buildings — both domestic and commercial — increases, and the need for higher density living continues to climb with urban populations, it will be crucial to ensure this growth does not drive energy and water consumptions higher.”
Conditioned to think differently
Charles Gallavardin, director of T3 Architecture Asia, first forayed into bioclimatic architecture in 2005. In cooperation with the World Bank, he built an affordable apartment building in Ho Chi Minh City, which houses 350 families in an impoverished neighborhood where AC bills were to be avoided.
“You don’t need to spend money on air conditioning, even in a hot climate like Ho Chi Minh, as long as your building is well designed,” Gallavardin tells CNN.
Covered open-air corridors, ventilated roofs, fiber-glass insulation and the use of natural materials meant the Ho Chi Minh City units offered both natural light and ventilation.
“We try to avoid big glass facades facing east or west, because that would make the building like an oven in a tropical climate,” he says.
“If you work with the main wind stream and have smart sun protection, you can do it — you really can design buildings that need no air conditioning in a hot place like Vietnam.”
Gallavardin explains that a typical bioclimatic T3 building is naturally about 5 Celsius (9 Fahrenheit) cooler than the outside temperature, with natural ventilation and the odd ceiling fan doing the rest of the work.
Before the 20th century, bioclimatic architecture was the norm, and it’s still visible today in vernacular buildings from Spanish haciendas to traditional Chinese village homes.
But with the invention of AC in 1902, by Willis Haviland Carrier, in the United States, bioclimatic solutions fell out of favor. Today, heating and cooling systems account for 40% of global building energy consumption, according to the International Energy Agency (IAE), which predicts that by 80% of air-conditioning demand will come from Asia by 2050.
