Beijing experiences extremely hot summers, with temperatures often rising above 30 degrees Celsius, and harsh, dry winters, with temperatures dropping to around minus 10 degrees Celsius. On 7 January 2021, the city had its coldest morning in 50 years, with the temperature plummeting to minus 19.6 degrees Celsius.
These extreme weather conditions create significant challenges for energy consumption. In the summer, the use of air conditioning increases electricity demand, while during winter, heating relies heavily on gas and electricity. To address this, it's crucial to improve building energy efficiency, promote the use of renewable energy, and optimize urban energy management. This approach will ensure sustainable energy use, reduce supply pressure, and cut carbon emissions.
A healthy and comfortable indoor space, combined with a green and natural outdoor playground, is essential for children's growth and education. Recognizing this, Beijing constructed its first passive-design kindergarten in 2019 – the Yizhuang X88 Kindergarten. This project embodies the principles of green, low-energy, and health-focused design.
The X88 Kindergarten is Beijing’s first educational passive house pilot project, certified by the German Passive House Institute (PHI). The project utilized prefabricated construction methods, incorporating steel structures with ultra-low energy technologies. This approach helps minimize the negative impact of steel structures on the building’s airtightness and thermal bridges by reducing these thermal bridges to the maximum extent. In addition, 3D BIM technology was used in the design to ensure harmony between the building and its structure.
The project adopts geothermal heat pumps and solar energy to significantly reduce the consumption of coal, natural gas, and other resources, thereby avoiding the emission of carbon dioxide and other pollutants. An indoor environment and energy consumption monitoring platform enables comprehensive control and optimization of energy use. To reduce excessive sunlight in summer, the building's east, west, and south-facing windows are equipped with electric shading devices, lowering solar radiation. The centralized fresh air system, developed in collaboration with Swiss company Zehnder, includes eight specially designed fresh air units with total heat recovery devices, achieving a sensible heat recovery efficiency of at least 75% and a total recovery efficiency of at least 70%. Additionally, sound-dampening equipment in the air ducts minimizes noise impact on children's activity rooms.
In order to improve comfort, the kindergarten has installed high-efficiency electrostatic air purifiers with a PM2.5 filtration efficiency of at least 97%. Additionally, there are 66 environmental detectors in place to monitor temperature, humidity, PM2.5 concentration, and CO2 levels in each room. This real-time data enables efficient management of indoor environments, including adjustments to temperatures and ventilation.
The X88 Kindergarten has reduced its annual electricity consumption by approximately 100,000 kWh and its carbon dioxide emissions by 290 tonnes after more than four years of operation, compared to current public building energy standards. Principal Xu reported that the kindergarten’s annual energy costs are about 135,000 yuan (approximately £15,000), saving over 60% compared to the average annual cost of 358,600 yuan (approximately £40,000) for standard kindergartens. Additionally, the consistent temperature and humidity levels not only keep children healthier by reducing colds, but also prolong the life of wooden furniture and teaching aids due to optimal humidity levels.
The use of passive design in public facilities, such as the Yizhuang X88 Kindergarten, holds immense significance for a mega-city like Beijing, which faces extreme climate conditions. This approach has the potential to significantly reduce the city's energy demands, contributing to a more sustainable urban environment. By lowering energy consumption and emissions, passive design alleviates the pressure on Beijing's energy infrastructure, providing its large population with healthier and more sustainable living conditions. This successful application in educational facilities showcases the vast potential and advantages of passive design, setting a new benchmark for sustainable urban construction. It highlights the critical role passive design can play in creating more resilient, energy-efficient, and livable cities.
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