Text/Monday Yan Tu/Tang Xiaoyi
In September, Zhejiang unnc Sustainable Energy Technology Center, the first zero-emission and energy-saving building in China, was officially put into use. Solar lighting, rainwater washing, geothermal heating, no waste gas emission during the operation of the whole building, and the energy of nature has been rationally utilized. Some people in the industry also questioned the energy-saving building: architectural critic Cathleen McGuigan used the word "green mansion" to point out three major problems faced by this kind of building, namely, large area, high cost and limited design.
"Please move the car, the bricks here are unusual."
When the reporters and their party drove to ——unnc Center for Sustainable Energy Technologies, the first zero-carbon energy-saving building in China, Qiao Dakuan, director of the research center standing at the door, saw the driver parked on the path leading to the entrance of the building and eagerly reminded them.
Qiao Dakuan pointed to the ground and said. After the driver moved the car, he looked at the ground intently to see if there were any traces of wheels running over. The reporter looked down and found that the path from the entrance to the building was about 100 meters long, covered with Shi Zhuan. These Shi Zhuan are regularly distributed with thumb-sized holes, which are the first "organs" of energy-saving buildings. "These bricks look ordinary, but they are actually very expensive. A rainwater collection system was installed under the brick. The water for washing hands and flushing toilets in the whole building depends on this system, so it can't bear the heavy pressure. " Qiao Dakuan explained.
British Joe Dakuan is an expert in the field of sustainable energy research. A year ago, Joe Dakuan was sent to China by Nottingham University.
From the outside, this five-story building is surrounded by transparent blue-green glass, and its irregular three-dimensional design makes it stand out among the buildings in Zhou Fangfang, feeling like a twisted Rubik's cube. The fan-shaped inclined design of the external wall of the building makes the shape of each side of the building look different, like a kaleidoscope. On the lawn around the building, a large area of solar panels and solar collectors were installed to form rows of "metal fences". "Whether it's vegetation, buildings or battery storage equipment, everything here is lovely green."
This kind of building is called zero-carbon building because it can solve the problems of electricity and water use by itself through renewable resources such as sunlight, geothermal energy and rain, and does not produce carbon dioxide. How can a five-story building with a total construction area of 1556.3 square meters achieve zero carbon emission? At noon on June165438+1October 1 1, the reporter stepped into this magical building.
The secret of breathing.
It's late autumn in Ningbo, and the outdoor temperature is around 15 degrees Celsius. However, as soon as the reporter entered the door of the laboratory on the first floor of the building, a warm current came to my face. Looking around, there is no shadow of air conditioning, and there is no rumble of any heating equipment running.
"Our air conditioner is invisible." Qiao Dakuan told reporters. This zero-emission building is not equipped with any air conditioner in the traditional sense, but the indoor temperature can be kept constant all the year round, 20-22 degrees Celsius in winter and 25-27 degrees Celsius in summer. The reporter followed Qiao Dakuan to the third floor of the ground, and the secret of warm winter and cool summer on the ground was presented. It turns out that the main exterior wall of the building is double-layer facade glass with a interlayer in the middle. The whole building is cooled and heated in this mezzanine.
Unlike ordinary air conditioners driven by electricity, it is renewable energy "water" that drives air to flow in the interlayer. 70-80 meters underground on the east side of the building, the ground source heat pump cold and hot water unit (hereinafter referred to as "ground heat pump") is buried deeply in it by piling and burying pipes. In summer, the geothermal heat pump takes the solar energy collection system as the hot water source, which drives the chiller to refrigerate, and the air circulates underground at a depth of 70 to 80 meters, bringing a refreshing chill; In winter, warm heat is sent up. In addition, because the building is equipped with electronically controlled "smart" windows, the opening degree of external windows and shutters can be determined according to the induction equipment installed in the building, and even the basement can breathe freely.
In addition, the ground heat pump can directly conduct hot air through the floor. Qiao Dakuan easily moved a piece of floor with one hand (the floors of buildings are all movable, which accords with the characteristics of convenient transformation of green buildings). There are many small holes under the floor. "You see, the hot air generated in the ground heat pump can pass through these holes and then penetrate into the space through the cracks in the floor. There will be this warm feeling in the room. "
In addition to ground heat pump, another important device of energy-saving building is a row of solar panels located on the south slope, which together with the metal decorative materials on the roof and windows of the building form a powerful solar power generation system, converting sunlight into enough heat energy to generate electricity to meet the power demand of elevators, computers, refrigeration fans and other equipment in the building. It is understood that solar panels can generate 600 kilowatts to 800 kilowatts per hour in sunny days, and can supply 60 to 80 100 watt bulbs to work at the same time. Don't worry about bad weather. There are four battery piggy banks with a width of about 1 m and a height of 2 meters in the hollow area of the lawn outside the building. These batteries are full and can cope with two weeks of rainy days. "Sometimes, in the case of continuous good weather, the building is full of electricity. When the four battery storage tanks are full, we will supply excess unused electricity to the adjacent gymnasium. " Qiao Dakuan said proudly.
The reporter observed that the zero-carbon emission building not only uses ground source heat pump and solar energy instead of coal to achieve "zero carbon emission", but also "saves electricity". Good light environment replaces the power demand of artificial lighting, even in underground laboratories. There is also plenty of light. Looking around the basement, the reporter found that there are four inclined triangular skylights at the top to ensure sufficient natural light to project in. The top of the whole building not only relies on the large glass in the south facade to introduce light, but also has a unique "lighting well" design inside the building.
The so-called "lighting well" is to install a transparent glass on each floor of the building instead of a floor tile; There is a big opening on the roof of the building to introduce natural light into the building, and the transparent glass on each floor introduces these light into each floor.
"According to the British building code, in the standard cloudy sky mode, the indoor natural lighting coefficient reaches 5% on average, and artificial lighting is not needed. The second floor of the zero-carbon building with the worst light can also reach an average natural lighting coefficient of 9.46%. There is no need to turn on the light from 6 am to 6 pm. " Qiao Dakuan told reporters. Of course, there is only one defect in the ingenious lighting well: girls in skirts will "walk out" when they walk up. "In summer, I will definitely remind female students to be vigilant." Qiao Dakuan said humorously.
It's not like building a house, it's like building an airplane.
"This is my dream house, full of magical energy. If you appreciate it from different angles, it will change into different shapes. " In September this year, Mario Cousinet, the designer of this building and a famous Italian environmental architect, stood in front of his works for the first time and could not help but sigh.
Two years ago, Mario received a case of designing a "zero carbon emission" building. In order to ensure that the whole building can get the maximum sunshine in spring, autumn and winter, and the summer is completely in the shadow, Mario simulated a number of irregular three-dimensional buildings with a computer. China's fan dance and lantern dance are playing on TV, and he is considering which one to choose. Although it is not clear whether this is a China dance or a sport, it inspired Mario to apply two traditional China folk crafts-folding fans and lanterns to the design. After several times of deformation and distortion, a "twisted lantern" was born, and each irregular glass curtain wall was like an unfolded folding fan.
On June 5438+ 10, 2007, Guo Xiaohui, the chief designer of the building construction drawing and deputy chief architect of Ningbo Design Institute, got the first draft of Mario's design. "I built a house for decades. For the first time, I read a first draft design like reading a' heavenly book'. " Originally, a building with a square meter of 1500 could only be regarded as a "piece of cake" by Guo Xiaohui, but this time, for the first time in his life, he had no idea. "When I saw the drawings, my heart sank. This three-dimensional building is extremely irregular. The south wall is crooked, and the east wall is crooked badly. To be honest, I really didn't want to take this job at that time. "
At first, Guo Xiaohui was always worried about the safety of the building. In previous designs, Guo Xiaohui occasionally encountered corners or walls with irregular designs, but he never drew a completely irregular deepening construction drawing of the whole building. Not only that, the outer curtain wall and the inner wall of the building need to keep a gap of 20 cm, and all the outer curtain walls are made of glass. The design of this "golden bell jar" stumped Guo Xiaohui.
At the beginning of the design, Guo Xiaohui tried to call overseas to ask Mario to change the design, but Mario insisted. Mario explained the metaphor of "twisted lantern" to him. "Mario told me that the irregular shape of building objects conforms to the concept of' multiple possibilities of renewable energy research', so it cannot be changed."
Guo Xiaohui was a little ignorant of the concept of green building at first, but finally decided to give it a try. First, he bought a set of software worth 654.38 million yuan to calculate the fixed point of building spacing. After numerous overseas exchanges. Finally, the architectural design was completed in March 2007.
"Generally speaking, the construction period of a building with 1500 square meters is about 7 months, but this building has been built for 1 year and 7 months." Shen Weiqi, assistant principal of unnc, said with emotion, "The school was originally planned to be completed in June 5438 +2007 10. In September of the same year, Professor Qiao Dakuan was invited to prepare for teaching. Unexpectedly, this energy-saving building is like a dystocia child, and the construction period has been extended by 1 year. "
An engineer involved in the construction told the reporter, "This is the most difficult house I have ever built." Because of the irregular surface of the building, he climbs up and down on the irregular scaffolding every day. The more difficult test is psychological stress. No one knows whether the high-tech environmental protection equipment can work normally after the building is completed. During the construction period, the engineer went to Beijing, Shanghai and other cities to inspect energy-saving buildings, but he was disappointed many times. At the beginning of this year, engineers heard that there was a similar energy-saving building in Tsinghua, and it was also made by Mario, so they learned from the experience.
"To my disappointment, many energy-saving devices in that building have become furnishings, and air conditioners and electric lights are still in use, which is of little reference value. Everything has to be explored by yourself. " He told reporters that in order to ensure the equipment installation of the first zero-carbon building in China is accurate, "I feel that I am not building a house, but building an airplane, and there can be no mistakes."
According to the school's calculation, in the next 25 years, the building will save 448.9 tons of coal and reduce carbon emissions10810.8 tons. What is the carbon emission of 108 1.8 tons? According to the data released by the United Nations Environment Program, if someone changes his 45-minute running on the treadmill to jogging in a nearby park, he can reduce carbon dioxide emissions by nearly 1000 grams each time; Replacing electric toothbrushes with traditional toothbrushes can reduce carbon dioxide emissions by 48 grams per person each time.
Energy-saving building or "green building"?
Since the completion of energy-saving buildings in Tsinghua University, the interest of domestic construction units and universities in energy-saving buildings has been increasing. Ningbo, the first zero-carbon building in China, once again makes people focus on "energy-saving building". Shen Weiqi told reporters that the building has attracted more than 30 groups of experts to visit since it was opened for two months (you need to make an appointment in advance), and many professionals expressed their hope to "copy" the energy-saving technology of zero-carbon buildings. The School of Architecture of Tongji University in Shanghai has planned energy-saving buildings for two years, and recently invited Qiao Dakuan to give a lecture.
In recent years, "zero carbon emission" and "carbon neutrality" are the hottest words in the international construction industry. In 2000, 573 construction projects around the world applied for LEED certification (energy and environmental building certification issued by the American Green Building Council). In 2008, this figure soared to 16000. The British Green Council issued a report saying that by 2020, all non-residential buildings will achieve the goal of "zero carbon emissions"; The United States, Canada, Japan and other countries have also introduced policies such as lowering loan interest rates and reducing taxes to encourage real estate developers to build energy-efficient buildings.
However, with the upsurge of energy-saving buildings getting worse, the industry has begun to question green buildings. Newsweek published an article entitled "Bad news of green buildings" in September. CathleenMcGuigan, an architectural critic, used the word "GreenMcMansion" to point out three major problems faced by green buildings at present, namely, large area, high cost and limited design. In addition, if the high-tech equipment is damaged or the thermal efficiency decreases before its service life, the energy-saving building may change from "zero energy consumption" to "high energy consumption".
In order to achieve the purpose of energy saving, energy-saving buildings occupy much more space than ordinary buildings. Las Vegas casino hotel Palazzo opened in June last year at 5438+ 10, covering an area of 8.3 million square meters, but it was also certified by LEED. In this regard, Qiao Dakuan said that with the innovation of environmental protection technology, 300 square meters of solar panels may become 150 square meters in the near future, or even be reduced to be installed inside buildings, and the shortcomings of green buildings occupying more land will eventually disappear.
Green buildings are expensive. Guo Xiaohui told the reporter, "The design cost of this zero-consumption and energy-saving building in Ningbo is nearly 1,000 yuan per square meter, which is 30 times more expensive than ordinary buildings. This does not include the design fee paid to Italian designer Mario. " An engineer involved in the construction also said that the cost per square meter of similar commercial buildings is about/kloc-0.5 million yuan, and according to his estimation, the construction cost of this building may be as high as/kloc-0.5 million yuan/square meter. In addition, the investment cost of solar panels, solar collectors and ground heat pumps is also high. When the reporter asked the school about the total cost of the building, Shen Weiqi, assistant to the principal, kept his mouth shut. He said, "Because this building is only an integration of many high technologies, it is of little significance to study its cost."
Talking about the design limitations of the "green building", Cathleen McGuigan wrote in the comments: "Although the ugly green building is better than the ugly non-green building, it still cannot hide its ugliness." This is just like how many people in China feel after seeing this zero-carbon building. The reporter interviewed some teachers and students randomly. They used words such as "novelty" and "weirdness" to describe the building, and some even exclaimed that "this is the ugliest building I have ever seen". Qiao Dakuan's explanation is that because energy-saving buildings themselves need to ensure adequate lighting, they must be moderately distorted. "It's like the leather clothes worn by Hollywood stars before, which is considered as a symbol of luxury and beauty. After being criticized by animal protectionists many times, fur coats became ugly instead of gorgeous. The fate of green buildings is just the opposite of fur coats. "
Professor Jiang Yi, academician of China Academy of Engineering and vice president of School of Architecture of Tsinghua University, said in an interview that both the energy-saving building in Tsinghua and the first zero-carbon building in China are just exhibits of comprehensive technology. He believes that promoting energy conservation is not simply installing some so-called energy-saving equipment, but must pursue the real reduction of actual energy consumption. For example, he said that some so-called "green houses" in Beijing canceled balconies, each family issued a dryer, and some solar cells were installed outside the building, which actually consumed much more electricity than ordinary houses; Some houses use a lot of advanced central air conditioners. The actual measurement shows that the annual power consumption of air conditioners per square meter is about 20 degrees, while that of ordinary split air conditioners is only about 2 degrees.
Jiang Yi pointed out that at present, the energy consumption per unit area of urban buildings in China is not high, only about 1/3 in the United States, and the average energy consumption of buildings on campus in Tsinghua University (except buildings built after 2005 near the East Gate) is 1/5 in the campus of Ivy League schools in the United States with the same climate. At present, the actual energy consumption of most ordinary houses in Jiangnan cities in China is basically close to the "zero carbon emission" buildings in developed countries.
"Urban buildings in China cannot rely on a large number of solar power generation, wind power generation and biomass power generation to solve building energy consumption, but rely on reasonable architectural design, energy system design, correct operation management methods, and users' energy-saving concepts and energy-saving lifestyles to achieve real energy conservation." Jiang Yi said.