To cope with the heat, some buildings are equipped with smart glass that changes with temperature or air ducts that utilize natural wind.
Nanchuan District, Chongqing, southwest China, August 2. (Photo: CFP)
This summer, many areas in China are enduring heatwaves. The average temperature for July was 23.2 degrees Celsius, the highest since 1961, according to data from the China Meteorological Administration. From now until mid-August, the country is expected to face two more heatwaves. Experts suggest that more preparation is needed in areas such as urban planning and architectural design to adapt to the changing climate, CGTN reported on August 3.
As one of the “furnace cities” experiencing prolonged summer heat in southwest China, Chongqing features many energy-efficient buildings that utilize advanced technologies such as shading, ventilation, and heat dissipation. For instance, a building covered with 10,000 m2 of smart glass at the Chongqing Free Trade Zone can respond to thermal signals. When the air temperature exceeds 35 degrees Celsius, the glass automatically becomes opaque, blocking sunlight and heat from entering the building, acting as a sun shield.
Smart glass building at Chongqing Free Trade Zone. (Photo: CMG).
The smart glass contains a type of nanogel polymer with evenly dispersed molecules at low temperatures, achieving a transparent state and allowing sunlight to pass through, according to Zhong Xianqiang, head of construction projects at the Chongqing Free Trade Zone. “As temperatures rise, the molecules cluster together, refracting and reflecting light at different wavelengths. The combination of this material with two glass panels creates smart glass that can block external heat,” Zhong explained.
In the Liangjiang New Area, a building named Chongqing House also features impressive self-cooling capabilities. Dozens of plant species, such as golden bamboo and ivy, are planted throughout all outdoor gardens, nearly covering the entire exterior walls of the building. From a distance, the building appears to be draped in a summer green coat. The dense vegetation creates its own microclimate, helping to lower the building’s surface temperature.
The L-shaped air duct from the northwest corner to the northeast corner of the building also helps to keep the space cooler, utilizing winds from nearby hills, according to Chen Hangyi, the chief designer of Chongqing House. “With the ventilation system and rainwater recycling, the building is estimated to save over 40% – 50% of energy per m2 compared to average energy-efficient buildings,” Chen said.
Chongqing House in Liangjiang New Area covered in greenery. (Photo: CMG).
In Guangzhou, southern China, district cooling systems (DCS) are widely used. Compared to traditional air conditioning, the new system enhances energy efficiency by utilizing a portion of renewable energy and waste energy.
At a new DCS station in the Guangzhou International Financial City, there is a tank with a capacity of 3,000 m3 of ice water. Each night, this station begins to make and store ice when the power load is low. The system helps reduce dependence on expensive and polluting thermal power during peak electricity consumption while maximizing surplus energy such as solar and wind during off-peak hours, thus improving overall electricity usage efficiency.
Meanwhile, central cooling systems can help reduce the need for numerous small air conditioning units throughout the city, thereby cooling the city and alleviating the urban heat island effect.
