Siphon drainage, also known as roof siphon rainwater drainage system, is a system that uses Bernoulli equation to calculate the pressure inside the drainage pipeline. By changing the diameter of the pipeline and pipe fittings, the pressure inside the drainage pipeline is changed, forming a full pipe flow and quickly draining under the action of pressure.
Siphon is a fluid mechanics phenomenon that allows for the suction of liquid without the need for a pump. After filling a inverted U-shaped tubular structure (called a siphon) with liquid at a higher position, it opens at a lower position.
The weight difference between the two ends of the siphon tube causes a pressure difference in the liquid, which can push the liquid over the highest point and discharge towards the lower end.

Same floor drainage, also known as "same floor installation" drainage, refers to the construction and laying of sewage and wastewater in the same floor plan, so that the discharge effect of sewage and wastewater reaches or exceeds that of similar and other drainage methods, smoothly enters the drainage main pipe (main drainage riser), and once the drainage horizontal pipe is blocked and needs to be cleared, the problem can be solved within the same floor.