GB 50189-2015 Design Standard for Energy Efficiency of Public Buildings
1 General Provisions
1.0.1 This standard is developed with a view to implementing the relevant national laws and regulations and principles and policies, improving indoor environment of public buildings, increasing energy utilization efficiency, promoting renewable energy application in buildings, and reducing building energy consumption.
1.0.2 This standard is applicable to energy efficiency design for new, extended and renovated public buildings.
1.0.3 Energy efficiency design for public buildings shall, according to local climate conditions, improve building envelope insulation, increase energy utilization efficiency of building equipment and system, and reduce energy consumption by heating, ventilation and air conditioning, water supply and drainage and electrical system of buildings using renewable energy under the premises of ensuring indoor environment parameters.
1.0.4 When the building height is more than 150m or the above-ground building area of a single building is more than 200,000m2, not only the requirements of this standard shall be complied with, but also experts shall be organized to conduct special demonstration on the energy efficiency design.
1.0.5 It shall be indicated in the construction drawing design document the energy-efficient measures taken in the project. Besides, the operating requirements should be described.
1.0.6 Energy efficiency design for public buildings shall not only meet the requirements of this standard but also comply with those in the current relevant ones of the nation.
2 Terms
2.0.1 Transparent curtain wall
The curtain wall through which visible light may be directly transmitted into the room.
2.0.2 Shape factor
The ratio of the building external surface area contacting with the outdoor atmospheric air to the enclosed volume of the building. The external surface area excludes the area of ground, and non-heating staircase internal walls.
2.0.3 Single facade window to wall ratio
The ratio of the window opening area on a facade of building to the total area of the facade, window to wall ratio for short.
2.0.4 Solar heat gain coefficient (SHGC)
The amount of solar radiation obtained in the room through transparent building envelope (door and window or transparent curtain wall) to the amount of solar radiation projected on the external surface of transparent building envelope (door and window or transparent curtain wall). The amount of solar radiation obtained in the room includes heat quantity obtained from solar radiation through radiation transmission and that of solar radiation transmitted into the room after absorbed by members.
2.0.5 Visible transmittance
The ratio of luminous flux of the visible light through transparent materials to that of the visible light projected on their surfaces.
2.0.6 Building envelope thermal performance trade-off
It refers to a method to calculate and compare full-year energy consumption by heating and air conditioning of reference building and designed building, and to judge if the overall thermal performance of building envelope meets the requirements of energy efficiency design, when architectural design fails to fully meet the index requirements specified in the Building Envelope Thermal Design, trade-off for short.
