Comfort requirements, resource occupation, and energy consumption constantly contradict building construction, use, and maintenance management [20–23]. In green buildings, the principle of comfort is emphasized not on the premise of sacrificing the comfort of the building but to meet the comfort requirements of human habitation as the setting conditions, the application of thermal storage and thermal insulation performance of materials, improve the thermal insulation and thermal insulation performance of maintenance structures, the use of solar energy for winter heating, summer cooling, through shading facilities to prevent overheating in summer, and ultimately improve the comfort of the indoor environment.
The construction, use, and maintenance of green buildings is a complicated technical system problem and a social organization system problem [24]. Although green buildings with high investment and technology can reflect the high-end level of human science and technology development, it is not only high technology that can realize green buildings’ function, efficiency, and quality. Suitable technology, local materials, and construction experience with regional characteristics are also the development methods for green buildings.
3.1. Critical points of green building design
The design of green buildings has been misunderstood from the initial greening and beautification design of a building area to the multi-system design that everyone now recognizes; after more than ten years, the cognition level of builders, designers, and users has been improved, and building materials, building technology and supporting products are also changing with each passing day [25].
Building energy-saving design has long been included in the scope of the construction drawing review; many mandatory code provisions have been able to ensure that buildings meet the national energy-saving standards; our majority of designers should not only meet the minimum requirements of the code but should pay more attention to cutting-edge scientific and technological information, master new materials, new technology, in the green design bold attempt, the courage to innovate.
The design process of green buildings involves many majors, focusing on planning, construction, water supply and drainage, electrical [26], HVAC, and other majors, as well as a whole system design. In this system, when the planning site is determined, the success or failure of green building design, the architecture profession plays a pivotal role. The following links must be focused on and controlled through study and work practice in the architectural design process.
- (A)
Water system
Green buildings to achieve water-saving goals, it is necessary to improve the utilization rate of water resources, that is, reuse wastewater and rainwater, the water environment system from the original "supply-discharge" model for technical improvement, add the necessary storage and treatment facilities, and form a "supply - discharge - storage - treatment - reuse" water resources recycling mode.
Community building planning needs to consider tap water, sewage, and rainwater and may include direct drinking water, municipal recycled water, groundwater and surface water introduction, transportation, discharge, and treatment. The collection, utilization, and discharge of rainwater are closely related to green building planning. For example, the floor area of the roof, green space, road, etc., and its surface paving materials directly affect the rainwater runoff and infiltration amount. Suppose the purpose is to increase the rainwater infiltration amount. In that case, it is bound to choose pavement, square, and other paving materials with good water permeability, improve the green space matrix, and increase its water storage capacity. Roof greening will also store part of rainfall, reducing the runoff of roof rainwater, and the runoff coefficient can be reduced from 0.9 to about 0.3.
Sewage and stormwater generally rely on gravity to transport water, so the design of sewage pipelines must match the site’s elevation design. Green space has the function of storing rainwater to increase rainwater infiltration and trap rainwater pollutants. Therefore, the terrain of green space in green buildings should be designed lower than roads, squares, etc., better to play the function and comprehensive benefits of green space.
The sewage and stormwater pipelines outside the buildings also need to be unified with the site road planning to facilitate the excavation and future maintenance of the pipelines. The water quality of rainwater runoff from roads and parking lots is poor, and appropriate pollution interception measures, such as low-potential green space and ecological retention systems, should be considered when collecting rainwater.
- (B)
Wind environment
Creating a good ventilation convection environment and establishing a natural air circulation system embody green design principles. Here, optimizing the design of natural ventilation is often overlooked. Especially for residential communities, to obtain higher economic benefits, developers usually pursue higher building density and floor area ratio, as well as floor spacing, as long as it meets the minimum sunshine spacing required by the code.
Green building technical standards
Green buildings are not one type of building. By analyzing green culture, philosophy, and concepts, we understand that green building is both a way of life and an idea. It does not necessarily refer to any particular type of building but covers all kinds of buildings, including residential, production, living, and public activity Spaces. From the perspective of a single green building, its green connotation is a series of things, including culture, ecology, environmental protection, and so on.
For buildings with high ventilation requirements, ensure each has a specific windward side. The wind shadow area behind the building is about three times the height of the building, which is far greater than the sunshine distance. If the building is placed in the same line only considering the sunshine distance, it will make the rear building have no direct windward side, which is very unfavorable to the ventilation of the back building. However, if the blind pursuit of wind shadow spacing contradicts the principle of land saving, this is a contradiction, and a reasonable trade-off should be made in the design process.
It is of practical significance to solve the problem of natural ventilation of buildings in cold winter and hot summer areas to reduce the power consumption of air conditioning. According to the local wind rose, the building group’s architectural form design, orientation, and layout achieve maximum natural ventilation. The building’s height, length, and depth significantly impact natural ventilation, and the rational arrangement of trees can also enhance the building’s natural ventilation. A simple rectangular body so that its long doors and Windows as far as possible towards the summer of the dominant wind direction, the ventilation effect is better when the building plane is "concave" shape or "L" shape, should be as far as possible to make its concave part facing the summer of the dominant wind direction; The depth of the building plane should not be too large, which is conducive to the formation of drafts. Under normal circumstances, the plane depth does not exceed five times the net height of the floor, which can obtain a better ventilation effect. The depth of buildings with unilateral ventilation should be 2.5 times the net height.
The one-frame building is conducive to natural ventilation; the smallest shape coefficient and various energy-saving indicators are easy to meet. The main room is on the summer windward side, and the lee side is in the auxiliary room. The inner gallery type of building is deeper and saves land, but only one side of the room is oriented well, which makes it challenging to organize indoor drafts and is not conducive to heat dissipation. The relative setting of doors and Windows can make the ventilation line short and straight, reduce the airflow roundabout path and resistance, and ensure the wind speed. If the corridor is long, the air vent can be set up in the appropriate part of the middle, or the stairwell can be used to make the air vent, which can form a draft, thereby improving the ventilation effect.
1.1. Application of solar energy technology
The application of solar energy technology in buildings mainly involves two aspects: photoelectric and photothermal. Photoelectric technology is primarily based on photovoltaic cells to provide electrical energy for the building’s use, and it also uploads electricity to the national grid. Here, we mainly talk about the application of photothermal technology in buildings.
Many years ago, the market accepted the domestic solar water heater. Residents’ enthusiasm for spontaneous installation and use is high, and the use effect is good. Since then, the application of solar thermal technology has had a good market prospect and mass foundation. However, the thermal efficiency of early products could be higher, and the installation of non-standard, disorderly, security risks and other problems have put forward a new topic - building integration.
Figure 2.
Evolution and History of Environmental Impact Assessment.
Figure 2.
Evolution and History of Environmental Impact Assessment.
Architectural integration emphasizes that solar energy products and architectural engineering design should be unified planning, synchronous design, and synchronous construction and put into use simultaneously as architectural engineering. Its advantage is that the effective hours of sunshine can be calculated in the planning stage, and the parts of the building roof and wall that can be installed with the collector are arranged in the area where the maximum sunlight can be obtained while avoiding the sunlight blocking off the back building due to the installation of the collector.
All-glass solar heat collecting vacuum tubes are famous in the domestic market, and the mature collectors abroad are flat collectors. Flat plate collector has the advantages of long life, high stability, and recyclability. Still, due to the slightly higher cost of flat plate and vacuum tube collectors, the performance of some cheap flat plate collectors could be better, making its development lag. Still, the development of flat plate collectors in the solar energy industry will be unstoppable.
The national standard GB50364-2005, "Technical Specifications for the Application of Solar Water Heating System for Civil Buildings," will divide solar water heating systems into three kinds of systems according to the range of heating water: central heating water, central-distributed heating water, distributed heating water; According to the operation mode of the system, it is divided into three kinds of systems: natural circulation system, forced circulation system and direct flow system. At the beginning of the design, it shall cooperate closely with Party A and the manufacturer to choose a suitable, reliable, and effective system for integrated design.
At the beginning of the planning and construction program, it is necessary to cooperate with water supply and drainage closely, electrical and other professionals, accurately calculate the collector area required by the building, reasonably determine the size and roof form of the building, and provide reasonable and safe initial conditions for the installation of light and heat, photoelectric heat collection components, so that it can be integrated into the building and become a constituent element of the building, rather than an unsightly building appendage.