What are the long -lasting "cool recipes" in Zhejiang's experience of continuous heat wave cities this summer?

Zhejiang News Client Pan Lu

An air -conditioning camera on the outer wall of a residential building in Hangzhou. Tuyuan Vision China

The heat caused the pedestrians in the city to have nowhere to hide. In order to avoid the continuous heat waves, the intersection is equipped with a sunshine, the subway is opened to cool down, and the air -raid hole has become a summer place ... Under the baking of heat waves, urban governance and folk wisdom have spawned various countermeasures.

However, it is obviously not enough to "cool down" to the more and more hot cities, which is obviously not enough to set up a limited response in the setting of shading sheds and opening a cool place. The planning and layout of a city, as small as the house where everyone lives, how can we increase the adaptability to the climate and the toughness of the city, so that the appropriate temperature and livable environment can become the most citizen can get Standard?

The reporter stepped on the street, entered the community, interviewed experts, and explored possible answers.

The more the air conditioner is blowing outdoors, the hotter

How should urban buildings cool down?

In the scorching sun, there are few pedestrians.

At 10 o'clock in the morning on August 21, the temperature was close to 40 ° C. Few pedestrians walk on the street. The reporter tried to avoid the heat in the shadow of the shop along the street, but from time to time, the hot air blowing out by the air conditioner was fainted.

Sanked worker Yang was responsible for the cleaning work of the section of the Jiefang Road. The sweat beads on her face fell up and landed on her neck, and the towels on her shoulders were soaked. "The air conditioner on the shop is cool, but the streets outside are getting hotter." She told reporters that the sidewalk on the side of the shop was "the most unbearable", and the air -conditioning exhaust was hotter.

The building is becoming an invisible carbon emissions "master". According to the "Research Report on China Construction Energy Consumption (2020)", in 2018, the carbon emissions of the entire life cycle of the construction industry accounted for 51%of the country's total carbon emissions.

Yan Xiaoqiang, technical director of Zhejiang University Architectural Design and Research Institute Co., Ltd., said that the operation of the building itself consumes energy, and at the same time releases heat and generates a certain amount of exhaust gas. With the development of urbanization, all kinds of forestry buildings have made the density of the city larger and larger. "Old found houses focus on piercing the wind and emphasize the construction of the building, which can effectively ventilate and cool down. The energy consumption and calorie of the building have made our city more and more hot to a certain extent. "

In the context of carbon peaks, carbon neutrality, ultra -low energy consumption buildings and (near) zero -energy consumption buildings have become the development trend of future buildings. According to the "Fourteenth Five -Year Plan" Hangzhou Green Building and Building Energy Conservation Work Plan, in 2022, it will implement demonstrations of ultra -low energy consumption projects with no less than 500,000 square meters and 10 (nearly) zero -energy consumption project demonstrations.

How to achieve low energy consumption? Xu Lei, director of the Institute of Architectural Design and the theoretical Research Institute of Zhejiang University, said that there are basically two paths. "If you can improve the material of the insulation layer and the outer wall, improve the performance of the building, and wear a lightweight clothes, you can reduce the use of air conditioners and save unnecessary energy consumption." Xu Lei said.

The other path is to make the building itself energy as much as possible. "The building has small wind energy, and the roof garden, roof pool, roof solar panel and other facilities should be set." Xu Lei said.

Glass curtain wall reflective dazzling

When will low -energy buildings popular?

The glass curtain wall of the building is reflected in the blue sky and white clouds. Tuyuan Vision China

The reporter walked near the Longxiang Bridge Metro Station, and the large glass curtain wall of the commercial complex reflected on the dazzling light.

Studies by optical experts show that the reflection light of mirror building glass is stronger than sunlight. The summer sun is reflected into the living room, which will increase the average room temperature by 4 ~ 6 ° C.

According to Yan Xiaoqiang's experience, low energy consumption buildings have some difficulty in landing, and the current penetration rate in Hangzhou is still low. "Large -scale glass curtain walls and simple and upright shapes are considered to be a symbol of high -efficiency and advanced modern cities. Developers and urban managers generally prefer this design."

The current market is not highly accepted by the accepted sunshade components and facilities that can effectively block the solar radiation. He believes that the existing technology can make the outer shade components exquisite and beautiful, and then cooperate with high -performance outer windows and outer walls, which can greatly reduce the calories obtained by the building during the day, and reduce the building's air conditioning calling. can. However, the various technologies of building low -energy buildings need to increase the cost of about 10%to 15%, and this cost requires a long recovery period to see energy saving benefits. "Unless it is a demonstration project, in reality, it is done in reality and is in place in place. There are actually not many. "

How far is we from low energy consumption buildings? Can the old community be renovated with energy conservation? Aunt Yao, who lives near Qianjiang Road, has lived in a house for nearly two decades. As the residence time increased, the heat insulation performance of the house became worse and worse, which affected the effect of air conditioning. After the Metro Na Liang point was set up on August 12, Aunt Yao walked from home to the subway station at 9 o'clock in the morning and until the sunset before returning.

Xu Lei has studied green buildings since 2005. He said that green buildings are not only the requirements for new buildings, but also include the transformation and organic renewal of existing buildings. "For example, the outer wall material of replacing the insulation insulation, the original rough and windows of the windows and windows installed the hot aluminum alloy hollow glass,"

Takeaway brothers say that there are not many large trees in large trees

How does urban greening improve micro -climate?

The little buddies ran on the street, and they knew where the shade of the tree was the coolest. Xiao Wang gave out for four or five years in Hangzhou. While waiting for the red light, he drank the ice black tea that had been hot. “现在行道树在景区附近的大树多一点，很多地方都稀稀拉拉的。”小王拍了拍自己装在电动车上的遮阳伞，“这个其实也不安全，但没办法。”公开数据显示， The green coverage rate of Hangzhou City is 40.58%, and the radius coverage rate in the park green space service radius is 90%. Chen Chuanjian, deputy dean of Zhejiang University of Technology Engineering Design Group Co., Ltd., said that at the same time that large green spaces increased, small gardens in the urban area were quietly appearing.

"Like the" Zhejiang Province Da Garden Construction Action Plan "and forestry community projects in the past two years, they are all promoting urban greening." Chen Chuanjian said that there will be more and more small gardens in the future, "Wetland can evaporate through the meter runoffs through the meter runoff. Realizing temperature adjustment, and small gardens that can be interspersed in the city through the evaporation of trees and water vapor, the improvement of local micro -climate will improve better than wetlands. "

Layer -layer buildings block the air duct

How to alleviate the city hot island effect?

How to make the peripheral wind into the city and alleviate the effect of urban heat island is also worth thinking about.

Why is there no wind? Yan Xiaoqiang introduced that Hangzhou's terrain is surrounded by mountains on three sides, but high -density high -rise buildings block the Jiangfeng channel. "In the countryside, the building spacing is large, and it can achieve heat dissipation and air circulation. And the sun is exposed to the city, there is no heat dissipation and steaming, and all of them have been absorbed into the steel bars." If you can increase the proportion of the lower surface of the heat -absorbing and fast heat dissipation of green space and river channels during planning, it will alleviate the effect of the heat island.

Chen Chuanjian believes that relieving the hot island effect requires urban air ducts, while ventilating can cool down and humidify, becoming a buffer belt for urban thermal groups. According to Yu Bu, an engineer of the Environmental Meteorological Center of the Hangzhou Meteorological Bureau, the construction of ventilation corridors should be considered when developing and constructing in the new area, and consciously avoid building tall buildings in the ventilation area.

"Climate adaptability will become an important consideration for urban future development space layout. We can reasonably control the boundaries of urban development and protect the cities' cold and wind sources instead of blindly spreading the expansion of large cakes." Yu Bu said.

Chen Chuanjian said that if you want to transform the "hot island" into "green island", you need to start with the aspects of strengthening urban greening and increasing urban waters, and use technical requirements such as green buildings and sponge cities to achieve the goal in the construction.

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