1.0.1 This standard is formulated with a view to implementing relevant national laws, regulations principles and policies, unifying the standard for water saving design in civil building, improving the utilization degree of water resources, and making water saving design realize safety, usability, advanced technology, economic rationality, guaranteed quality and convenient control under the premise of meeting requirements of users for water quality, quantity, pressure and temperature.
1.0.2 This standard is applicable to the water saving design of civil buildings in newly-built, reconstructed and expanded residential communities and public building areas; it’s also applicable to the water saving design of industrial buildings.
1.0.3 In addition to meeting the service requirements, the water saving design in civil buildings shall also provide convenience for construction, installation, operation, management, maintenance, inspection and safety protection.
1.0.4 This standard specifies the basic requirements for water saving design in civil buildings. Where this standard conflicts the requirements of state laws and administrative regulations, the state laws and administrative regulations shall prevail.
1.0.5 Besides this standard, the water saving design in civil buildings shall also comply with the relevant national standards.
2 Terms and Symbols
2.1 Terms
2.1.1 Rated water consumption for water saving
It refers to the average daily water consumption after adopting the domestic water saving devices.
2.1.2 Water consumption for water saving
It refers to the water consumption calculated according to rated water consumption for water saving.
2.1.3 Reversed return layout
It refers to the layout of hot water pipeline in which the total length of water supply and return pipelines corresponding to each water distribution point is basically same.
2.1.4 Diversion of tee-union
TY type or downstream tee with flow deflector used to direct the return water in circulation return pipe flow in the same direction.
2.1.5 Return pipe fittings
The fittings used to realize water circulation by making the low temperature water flow to the pipeline bottom and high temperature water flow to the pipeline top based on the principle of different water densities under different temperatures.
2.1.6 Master circulating pump
It refers to the hot water circulating pump set on the hot water return main of the district hot water supply system in the community.
2.1.7 Unit circulating pump
It refers to the hot water circulating pump set on the hot water return pipe of single building in the district hot water supply system in the community.
2.1.8 Water productivity
It refers to the ratio of the direct potable water amount output by raw water (generally the tap water) through deep purifying treatment to the raw water amount.
2.1.9 Rejected water
It refers to the high-concentration waste water discharged from the raw water (generally the tap water) during the deep purifying treatment process.
2.1.10 Sprinkling irrigation
It refers to an irrigation method, by which the pressurized water is delivered to the irrigation area through pipeline and then dispersed to fine water drops by spray nozzles and uniformly sprayed to the greenbelt and trees.
2.1.11 Micro irrigation
Micro irrigation is short for micro water irrigation, by which the water and nutrient substance are delivered to the soil surface or soil layer nearby the lawn and tree root in small flow.
2.1.12 Underground micro irrigation (permeate irrigation)
Underground permeate irrigation is a kind of underground micro irrigation, by which the water is permeated to the soil in a definite time and quantity through emitters (porous pipe) buried in the lawn and tree root zone according to the water demand of crop growing.
2.1.13 Drip irrigation
