Beijing jinmaofu primary school is a model of primary and secondary school design for "green school" projects."Green school" means on the basis of realizing the function of the basic education, guided by the sustainable development strategy, adjust measures to local conditions to adopt all kinds of energy conservation and environmental protection in construction technology, and in the work into the management and the teaching measures are beneficial to the environment, make full use of favorable conditions face-to-face, comprehensively improve the quality of the environment between teachers and students of the school. "Green school" makes all kinds of active and passive green ecological technology measures and management methods reasonable, optimized and integrated. While emphasizing energy saving and environmental benefits, it also integrates humanistic management benefits.

1. Project overview

Jin Maofu primary school project is located in 15 wide canal road to A4-4 plot, northwest of Beijing east road, the ancient philosophers bay and wide canal road, construction land area of 13400 m2, volume rate is 0.6, a total construction area of 10079.7 m2, building area of 8040 m2, including the ground underground construction area of 2039.7 m2, building 18 meters high, building the ground layer 4, 1 floor underground, building density is 16%, the rate of 35%. The project has been awarded the national green building three-star design logo certification.

2. Construction objectives

Jinmaofu primary School project will be the first to apply for the design and operation logo of a three-star green School in China, with leed-school certification of the highest platinum level as the construction target. At the same time, the project participated in the compilation of green campus standards, and was included in the first batch of pilot projects, and participated in the construction of campus green monitoring and exhibition platform. We will build a state-level green primary school, open up a platform for international education system to exchange visits, and build the project internationally. We will build the project into a demonstration area for low-carbon schools to conduct experimental and popular science education. Moreover, jinmaofu primary school has integrated green environmental education into the curriculum, and implemented green environmental education for children in a planned way. Meanwhile, it actively plans to exchange cultural, educational and environmental activities with LEED platinum schools in other countries.

Under the evaluation standard of the LEED certification system, definite target in green building, so as to make the feasible design scheme, make the project in site selection, construction of the field water saving and energy consumption, building materials, indoor air quality, innovative design and so on to achieve LEED - School certification system standard, provides the high quality for the students and staff, low maintenance, healthy and comfortable living and working environment of learning. Up to now, no primary or secondary school in China has ever passed LEED certification. Jinmaofu primary school will be the first vivid example of implementing LEED platinum standard in school construction in China.

3. Green school program

3.1 sustainable sites

3.1.1 site selection

Site no. 15, guangqu road, chaoyang district (the project is located in the a4-4 plot of the site) is the former site of Beijing chemical industry factory. The site scope starts from east fourth ring road and baiziwan east road in the east, reaches to guangqu road in the south, reaches to the middle road in the west, and reaches to the south road in the north. There are no environmental sensitive points in the project area, such as nature reserve, scenic spots and historical sites, and cultural relic protection units. The project is located in the urban area, which is a typical urban ecosystem. The vegetation is mainly artificial vegetation, and the plant species is mainly common trees, shrubs and lawns. There are no rare wildlife and state-level protected plants and animals, and there are no sensitive plants and animals.

Chemicals discharged from the original site of the project, the Beijing chemical plant, caused cumulative pollution in the soil. After the first-level development of the land and the relocation of the plant, the contaminated soil was left on the site. The site was found to be contaminated with arsenic, mercury and cadmium. The specific treatment scope of soil pollution in the project is determined according to the monitoring site location, health risk impact and the spatial arrangement of production facilities or workshops historically involved with the pollutant. The site no. 15 of guangqu road (the project is located in the a4-4 plot of the site) needs to be treated with a soil area of 3.38 hectares and a total soil volume of 44,900 cubic meters, including 1.28 million cubic meters of heavily polluted soil and 43,600 cubic meters of lightly polluted soil. According to the environmental assessment report of the site of the former Beijing chemical plant and the remediation plan of the contaminated soil of the former Beijing chemical plant, the project was carried out by a company with relevant professional qualifications to clear and remove the site at no. 15 guangqu road, in which the heavily polluted soil was safely disposed of by landfill, while the lightly polluted soil was disposed of by landfill. According to the remediation and acceptance report issued by the Beijing academy of environmental protection science, the clearance of site 15, guangqu road (including the a4-4 plot of the primary school project) has met the requirements set forth in the remediation plan for contaminated soil from the former Beijing chemical plant.

3.1.2 greening and permeable ground

Jinmaofu primary school project covers an area of 3140 m2, the red line covers an area of 20367.3 m2, and the green area covers an area of 11939.5 m2. VP grass planting circle pavement turf area of 267 m2, outdoor permeable surface area ratio up to 70.85%. At the level of outdoor greening, jinmaofu primary school is 25% higher than that of Beijing. Meanwhile, the green area of the roof is all planted roof.

3.1.3 roof greening

Roof greening can improve the appearance of the urban environment, relieve the atmospheric dust, purify the air, alleviate the urban heat island effect, the role of heat insulation on the roof, reduce the use of air conditioning, energy saving and other functions

There are many provisions in LEED on greening impacts, such as: SS C5.1 requires the use of place and at least 50% of the outdoor site area or 20% of the site area suitable for plant restoration and protection (roof greening can be included in the calculation if the two are larger); SSC5.2 required green land rate is 25% higher than that of Beijing (roof greening can be calculated); SS C7.2 requires that at least 50% of the roofing be planted roofing, and if 100% of the greening roofing area is planted roofing, innovation points can be obtained 1. Therefore, planting roof is considered to be adopted in all parts of the roof of this project that can be afforested except the equipment area.

3.1.4 construction of public transport

The bus system in the region includes rail transit, large station express, bus line and other forms, and is basically laid along the east third ring road, east fourth ring road, guangqu road, south mofang road, west dawang road and other traffic trunk roads, with a large number. There are 6 bus routes within 500m from the main entrance and exit. The bus routes are named as no.11, no.23, no.35, no.348, no.513 and no.541. The name of the bus station is: da jiao ting qiao west station.

In addition, there is the subway entrance and exit of line 7 at the intersection of guangqu road and baiziwan east road. The distance between stations of line 7 is about 1.5 kilometers, which belongs to the line with short interval. It is planned to open in 2014.

3.2 water-saving scheme

The Beijing municipal water authority said in May that the city's per capita water resources had fallen to 100 cubic meters, well below the internationally recognized water shortage threshold of 1,000 cubic meters per person, and equal to 1/10 of the international water shortage threshold. Making full use of water resources is the focus of the Beijing area, especially the green schools, and one of the important ways to ease the water stress.

LEED has higher requirements for water-saving appliances. The amount of water saved by water-saving appliances is at least 20% less than the amount of water used by LEED as the reference standard. For water-saving appliances to obtain LEED platinum certification, the amount of water saved by water-saving appliances is required to be higher. Water-saving appliances meeting LEED standards were selected for the project, as shown in table 3.

Table 3. Parameter requirements of water-saving appliances

Type	Instruments	Water parameters
Sanitary ware	Big toilet	≤6L/3L
	urinal	≤3L
	tap	≤1.9 l/min/time consumption of induction faucet shall not exceed 1L
	shower	≤8 l/min
Water appliances	The washing machine	Water consumption per cycle: <1L/L
	A rack dishwasher	< 3.785 L/rack
	The ice maker	Ice preparation >79.37 kg: <75.7 litres /45.36 kg
		Ice preparation <79.37 kg: <113.56 l /45.36 kg
	Electric steamer	7.57 l/h

The project USES municipal water as a source of green irrigation and flushing water. The annual water consumption from non-traditional water sources is: 4,276.97 tons/year for washing sanitary appliances; Green irrigation 628.09 tons/year. The utilization rate of non-traditional water sources reached 60.49%. In addition, the project USES sprinkler irrigation and drip irrigation water-saving technology to save green irrigation water.

3.3 energy and atmosphere

3.3.1 design of envelope structure

The basis of the design of the envelope structure of this project is mainly based on the minimum building energy consumption requirements of LEED.

1) external wall: heat transfer coefficient ≤ 0.32w /(m2·K), equivalent to 95mm extruded polystyrene plate;

2) external window: heat transfer coefficient ≤ 1.80w /(m2·K), shading coefficient ≤0.35;

3) roof: heat transfer coefficient ≤ 0.25W/(m2·K); Equivalent to 120mm thick extruded polystyrene plate;

4) total window-wall ratio of each orientation ≤ 0.4.

3.3.2 exhaust heat recovery

The project adopted a total heat recovery fresh air unit, including medium and effective filtration section, surface cooling section, wet film humidification section and heat recovery section. The heat recovery rate was 60%, and the filter was F7 medium and effective filter, with an efficiency of 65%. After installing the rotary full heat exchanger, the annual operation cost saved is about 35397.96 yuan, and the static investment payback period is 6.82 years. If add heating boiler, cooling tower, circulating water pump, cold coil pipe and other components to save investment and operating costs, the static investment payback period will be shortened. The designed service life of the heat recovery wheel shall not be less than 10 years.

3.3.3 solar photovoltaic power generation

In recent years, solar photovoltaic power generation technology has developed rapidly. China's photovoltaic industry started in the 1970s and entered a period of stable development in the 1990s, with the output of solar cells and modules gradually increasing year by year. After more than 30 years of efforts, it has ushered in a new stage of rapid development. There are very favorable natural conditions for the development and utilization of solar energy in Beijing. Through the survey of solar energy resources in Beijing, it is found that the taienerg resources in Beijing are relatively rich areas, with the annual sunshine hours reaching about 2600 hours and the annual cumulative solar radiation amount reaching 5227.14 MJ/m2. In addition, the solar energy resources in all parts of Beijing have a stable degree and belong to the stable grade, which provides a very favorable natural condition for the use of solar energy in Beijing. Therefore, the prospect of developing solar energy resources in Beijing is good.

LEED for School also regulates the use of renewable energy: different scores are given for the proportion of electricity generated by renewable energy in a building's total electricity consumption. At the top of the vehicle shed, the project adopts solar photovoltaic power generation with a power of 235Wp solar cell modules. 11 modules are connected in series to form a photovoltaic square array, which consists of 4 photovoltaic squares. The power of each photovoltaic square array is 2.585kwp, and the total power of solar cell modules is 10.34kwp. The annual power generation of the photovoltaic system is 11585.62kwh, and the annual power consumption of the building design is 310920kWh. Therefore, the generation of solar photovoltaic power system of the project accounts for 3.73% of the total power consumption of the building.

3.3.4 green lighting

In the project, standard classrooms, teachers' lounge, office, computer classroom, reading room, scientific research laboratory, canteen, kitchen, moral education exhibition room, calligraphy classroom, class classroom and power distribution room are all equipped with energy-saving fluorescent lamps, and the gymnasium is equipped with metal halide lamps. Energy-saving light source efficient lamps and lanterns with energy-saving inductive ballast, the requirements of cos ≥0.9, ballast should meet the national energy efficiency standards. The lighting power density value of each room or place is not higher than the current value and target value stipulated in GB 50034 of the current national standard "architectural lighting design standard".

Table 4. Lighting power design value of each main function room

Room type	Design illumination value (Lx)	Lighting power density (W/m2)
		The actual value	The current value	The target
Standard of the classroom	313.5	8.8	11	9
Classroom lounge	101.2	3.36	5	4
Office	273.1	6.5	11	9
Computer room	313.5	8.8	11	9
Reading room	298.7	8.89	11	9
Science laboratory	327.8	8.79	11	9
Gym/td>	292.3	8.64	11	9
Dining room	143.7	4.28	11	6
The kitchen	12.8	5.17	11	6
German exhibition room	275.4	6.57	11	9
Calligraphy class	282.3	6.71	11	9
The classroom	301.6	7.96	11	9
Transformer room	182.2	3.8	11	7

3.4 materials and resources

3.4.1 civil materials

Recovery and/or utilization of harmless construction and demolition waste, development and implementation of a construction waste management program, waste recycling proportion should be more than 75%. Use materials containing recycled components so that the sum of the post-use materials and one-half of the pre-use materials in the project materials account for 10% of the total value of the project materials and try to increase this proportion. Building materials and products sourced, harvested, recycled and produced within 500 miles of the project cost at least 20 percent of the total value of the project materials. At least 50% of new wood materials and products used are certified according to the American forest stewardship association (FSC) principles and standards for use of wood building parts. The construction materials of this project are recycled civil materials with more components, and materials within 800 kilometers of the production site and processing site are preferred, and certified wood is selected.

3.4.2 decoration materials

All adhesives and sealants, paints and coatings, floor systems, synthetic wood and fiber products, furniture and furnishings, ceiling and wall systems installed within the building must meet California health service standard practices for testing of organic volatiles from different sources. The carpet is certified by CRI green label. Composite wood and fiber products used without urea formaldehyde resin materials. The adhesives, sealants, paints and coatings required for the project are low-voc products, the carpet is certified by CRI green label products, and the composite wood and fiber products are made of urea-formaldehyde free materials.

3.5 indoor air quality

3.5.1 track of the new air volume

Leed-school puts more emphasis on indoor environmental quality project. Air conditioning room is determined according to function and number of users. The indoor fresh air volume of each room is maximized in the design standard for public building energy conservation, the architectural design code for primary and secondary schools, and LEED for School. The main functional Spaces of the classroom, office, dining room and activity room are equipped with CO2 concentration sensors, which are combined with the fresh air unit. Open the fresh air device when the concentration is greater than 0.1mg/m3. The fresh air in each room can be electrically controlled, and the fresh air system is turned off when the teaching is over.

Table 5. The design code for primary and secondary schools requires the ventilation capacity of each main functional room

The name of the room	Air change times (times /h)
Classroom, physics, biology laboratory	3
Wind and rain playground, toilet	10
Health room	2
Students' dormitory	2.5

The energy conservation design standard for public buildings requires new air volume

The room type	Fresh air volume (m3/ (h·p))
	Design value	Standard values
The office	30	30
The classroom	11	11
Sports room	20	20

LEED certification requires new air volume

The room type	Fresh air per unit area	Personnel fresh air volume
	（cfm/sf）	（m/人）
Classroom, computer classroom, technical classroom	0.12	10
Office, conference reception room	0.06	5
Sports hall, wind and rain playground	0.3	15
The dining room	0.18	7.5
The reading room	0.12	5
Dance studio, classroom	0.18	10

3.5.2 natural lighting (light guide tube)

The project USES a sunken courtyard with an outside window in the basement. About 86.10% of the main functional Spaces on the ground meet the lighting coefficient requirements of GB 50033 -- 2001 in the architectural lighting design standard. After the light guide tubes were arranged on the second and fourth floors, about 91.20% of the main functional space on the ground reached the requirements. About 79.48% of the main functional space on the first underground floor of jinmaofu primary school reached more than 0.5%, which improved the lighting effect of the underground space.

3.5.3 indoor air quality monitoring system

The main functional Spaces of the classroom, office, dining room and activity room are equipped with carbon dioxide concentration sensors, which are connected with the fresh wind. The monitoring system of building equipment is composed of sensors, direct digital controllers, transmission lines, network controllers, hubs, actuators and displays. The monitoring center is located in the control room of the first floor building. Carbon dioxide concentration detection system is incorporated into BAS system for monitoring or monitoring. BAS system has the functions of manual/automatic status monitoring, start-stop control, operation status display, fault alarm, temperature and humidity monitoring and control, as well as the realization of various logic control relationships.

3.5.4 external shading

The project is equipped with metal louver shade in the south exterior window. Metal blinds can be adjusted according to different weather conditions and sunshine conditions, also can be adjusted according to the need.

4. To summarize

So far, there are only two leed-school programs registered in China, but no School has passed LEED certification. Leed-school accreditation is still in its infancy in China, but green schools are gaining momentum. As the most influential green building certification system in the world, LEED certification will develop rapidly in China, with more and more School programs registering and obtaining leed-school certification.

However, due to the differences in national conditions, some provisions in the LEED certification system do not conform to the actual situation in China. Therefore, China's relevant professional and technical personnel need a lot of work to do, on the one hand, to understand the LEED certification system, flexible and efficient LEED certification system related items reflected in China's green building projects; More importantly, we should combine the specific conditions of our country, absorb and learn from the green building evaluation systems of various countries, including LEED, and form our own green building evaluation system applicable to different types of buildings.

Reference

[1] LEED 2009 for Schools New Construction and Major Renovations Rating System, USGBC

[2] LEED 2007 for Schools New Construction and Major Renovations Rating System, USGBC

[3] LEED Projects Directory [EB/OL], USGBC.