The so-called “sky wells” provide ventilation and stop the sun!
The sight of the huge housing complexes in which a large part of China’s population is crammed is startling.
You get hot and claustrophobic just by the sight of the concrete mastodons and the idea of the thousands living in their boxes.
This is the modern-day look of the country’s huge megacities, only centuries ago, when life looked quite different, the Chinese had their own way of climate-friendly construction.
Part of it was the sky wells in the houses, something like the patio or atrium in the southern parts of Spain. These are small patios, sometimes with water, whose function is to cool.
The heavenly well is typical of traditional houses in southern and eastern China.
What distinguishes it – compared to the architecture of the courtyards in other parts of the country – is that it is small and narrow and not so exposed to the environment – for example, sun or rain. The upper part is formed by the elongated roofs of the building.
Such construction was common in the houses of the Ming and Qing dynasties, i.e. from the 14th to the 20th century. These buildings are large and designed to accommodate large multi-generational families. In the middle is the small yard.
The roofs form the small courtyard.
Typically, it is usually rectangular, in the center of the house. There are rooms around it on all sides. Larger houses may have two similar wells.
One of the goals of such construction was precisely to maintain lower temperatures. When the wind blows over a building with such a courtyard, it enters through the opening. Usually, the air outdoors is cooler than that indoors or in this case, semi-outdoors.
It descends along the walls to the lower parts of the building and creates an air flow, displacing the heated air of the yard, which in turn exits through the well.
In addition, the technique served to let in light, but also to limit excessive exposure to the sun, for better ventilation and rainwater collection, Yu Yuhong, who has been involved in restoration for 30 years, told the BBC. of sky wells in Wuyuan County in southeastern Jiangxi Province.
In the southernmost parts of the country – the provinces of Guangxi, Guangdong and Hainan, and also in the north of Vietnam, the longer and hotter summers required these smaller and narrower courtyards.
Thus the rooms and walls around the well stop the light and its bottom remains cool. In addition, warm air from the house can rise and exit through the opening at the top – just like a chimney.
As a transitional space between inside and outside, the well also acts as a heat buffer. However, it is most effective when there is water in the enclosed space.
Its evaporation cooled the air, and the water came from the rain that collected in the well. That is why the courtyards have gutters, which were used to drain the rain falling from the roofs. In the center of many of the wells there is also a stone tub to hold the water, and on cold days – for fires.
Nowadays, studies have even been done, according to which the temperature in such a yard is up to 4.3 degrees lower than outside.
Such buildings have existed for hundreds of years in China, but they have gradually been forgotten by people seeking more modern conveniences. In the last two decades, however, there has been a tendency in the country to return and restore the old architecture – part of the larger trend for the revival of traditional culture.
Thanks to this, the buildings with sky wells are slowly reappearing.
Yu Yuhong, for example, restored a 300-year-old house with a well for a British man and his Chinese wife. The two decided to give new life to the three-story building and turned it into a boutique hotel.
The hotel also has air conditioners, but the two have decided to keep the common space around the well in its original form – without a roof and with natural ventilation. This, they found, provides natural coolness in the house as well.
The return to old methods is also encouraged by the Beijing government’s policy of greener construction, with less resource consumption and less pollution, including the issuance of green standards for good insulation and environmentally friendly building materials.
Therefore, when designing new, energy-saving buildings, architects turn to the principles of sky wells.
An example is the building of the National Heavy Vehicle Engineering Technology Center in Jinan.
The center is housed in a new, 18-story building with glass walls. However, inside there is a giant sky well – from the fifth to the top floor. This helps ventilation and lighting in the central area and reduces the use of electricity.
Something similar is also used in the construction of some skyscrapers, but instead of a courtyard, they only have the idea of such ventilation.
A 68-story building in Dongguan, Guangdong province, has indoor “wind pipes” that provide a breeze on each floor and work in the same way as wells. Thus, a pleasant temperature is maintained in the building in autumn and spring.
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However, reviving old techniques is not as easy as it might seem. Traditional wells have different shapes and sizes, according to the specifics of the specific place such as light and rainfall.
Therefore, their application today requires the appropriate approach and research.
The nostalgia for these patios is probably due to something else. They also had the function of a place where families could gather and communicate.
“Perhaps lifestyle changes also evoke nostalgia in people who live in concrete jungles,” said Wang Zhengfeng, an environmental scientist at Leiden University in the Netherlands.
Illustrative Photo by Maria Orlova: https://www.pexels.com/photo/tropical-resort-spa-with-moroccan-bath-pool-4916534/