How to build schools for extreme heat without air conditioning

Heat can threaten children's education

Air conditioning fuels global warming

Passive cooling is the new trend among architects

Emma Batha

Kere, who had studied abroad for many years, returned to his village after completing his studies to build an airy and light school that would allow children to learn comfortably in temperatures as high as 45 degrees Celsius.

The architect from Berlin did not use the air conditioner. He incorporated cooling features in Gando Primary School, which he has applied to other projects throughout Africa.

Kere is one of many architects who are pioneering sustainable designs for schools in a world that's warming.

From Brazil to Vietnam, studies show that heat has a significant impact on learning. The World Bank warned in a report published last year that climate change is a threat to educational attainment and creating an "economic bomb".

Experts recommend that classrooms not exceed 26 C.

Kere's decision to build the Gando school out of clay was initially shocking. However, the material acts as a natural thermometer, absorbing the heat during the day, and releasing it in the evening.

Kere says that while concrete and plate-glass look modern, they can make a building hot. This means air conditioners are needed.

It's a vicious cycle. Air conditioners that use a lot of energy and expel warm air outside contribute to global warming. This in turn fuels the demand for air conditioning.

Instead, Kere uses passive cooling techniques.

The classrooms of Gando have openings on both ends. This allows for cross-ventilation. The overhanging roof is elevated above the perforated lower roofing, which improves air circulation.

Kere, a Kenyan architect, was inspired to design a campus for a university by the termite mounds that regulate temperatures with natural ventilation. The low openings of the buildings allow fresh air to enter while the terracotta towers allow hot air to escape.

SOCIAL CHANGE

In the Thar Desert in north-west India, temperatures this year reached 48 C. The vegetation is sparse and sandstorms occur frequently.

Diana Kellogg, an architect from New York, designed the Rajkumari Ratnavati Girls School. It is a large oval sandstone building rising out of the Rajasthan desert.

The orientation and shape of the building allows the prevailing wind to blow around the school. Lime plaster applied on the walls inside has a cooling effect.

Venturi effect is a phenomenon that accelerates airflow through lattice screens. They are inspired by the traditional Indian jali screen. The school uses solar power to run and collects rainwater.

Kellogg says that temperatures inside can be up to 10 C lower than the outside temperature, which contributes to higher attendance.

She believes, like Kere that good architecture can inspire social change.

Rajasthan has India's lowest female literacy rates, but Kellogg says the massive scale of the school sends a powerful message about girls.

She said, "It's improved their status in the community." The girls are proud to attend and call the College 'The College.' "When I visit the boys, they say, Build one for us.'"

Greening Schools

Even countries with temperate climates are looking for ways to cool down schools, as the climate change will bring more heatwaves.

Britain said that new school buildings must be future-proofed to withstand a temperature increase of 4 C.

The Victorian-era schools, with their large windows and high ceilings, are better equipped to handle heatwaves than the newer schools that have been designed to keep heat inside.

But education does not just happen indoors. Many cities are making their playgrounds greener to help children develop.

Planting trees can reduce temperatures by up to 6 C in urban areas. This is due to the shade and water vapour released.

Paris aims at converting all asphalted schoolsyards into green oasis by 2050.

Cool paint is another solution. Scientists are working on high-tech paints that may outperform air conditioners.

BUILDING WITH CLAY

Engineers are creating sophisticated products and systems to regulate temperature, from geothermal cooling to smart glass.

Sustainable architecture, according to German architect Anna Heringer, means using local materials.

Heringer is known for his use of mud, "a low-tech but high-tech material".

Heringer added that clay balanced humidity, which can cause physical discomfort during extreme heat or cold.

"Architects are often too technical but the solution is right in front of them."

In Tanzania, she was told that villagers built concrete houses for status but slept in mud huts at night.

Heringer explained that, contrary to popular belief, clay walls don't dissolve in rain. Heringer said that there are easy techniques to stop erosion and that a natural crystallization will strengthen the walls with time.

Heringer added that the schools she built in the past 20 years have needed little maintenance.

There is no air conditioning in some classrooms, but solar-powered fans are used in others. She said that not only is it a waste of energy, but switching constantly between heat and cool can be harmful to children's health.

Kere, whose international commissions includes Benin's parliament building and the Las Vegas Museum of Art, said that his studio receives many inquiries about passive cooling and building with clay.

(source: Reuters)