In October 2005, the second biggest rainwater harvesting system was built on the campus of Seoul National University. The university is considered to be the leading scientific and technical educational institute for engineers in South Korea. Professor Mooyoung Han teaches water quality management and water recycling technology. His particular concern is the utilization of rainwater. He initiated pilot systems in the student hall of residence, which was ready for operation in 2003, and in the B 39 institute building, which was completed in 2005.
1,000 students and employees work in this building. Here 60-90 m³ of rainwater are required for flushing toilets every day. Gauges were installed with the system technology, enabling Prof. Han’s students to examine the quality and suitability of the water that comes from the 3,652 m² of roof surface. A small quantity of rainwater is channeled through a WFF 100 vortex fine filter, from WISY AG, on its way to the cistern. A comparison with other filter techniques has shown that the WFF 100 is reliable in separating dirt and particles from the usable water. Consequentially, there is no need for the cistern to be cleaned at regular intervals.