How it works

See pdfAn Introduction to Siphonic Drainage.

Siphonic drainage is actually very simple in principle and all systems work in exactly the same.

Baffle plates inserted in the outlets restrict air entering the top of the system which, when combined with carefully sized pipework, causes the system, horizontal and vertical, to run full. In a very similar way to a simple tube siphon (such as you would use to empty a fish tank), the action of water dropping down the downpipe will cause a negative pressure to form at the top. This negative pressure can be harnessed to suck water along a collector pipe installed horizontally connecting the outlets at high level.

Benefits:ยทHow it works-2

  • Each gutter has only one or two downpipes, which can be located at the end of the building, allowing free use of floor space by eliminating downpipes and therefore reducing columns.
  • The horizontal collector pipe can be very close to the gutter, allowing full use of internal space.
  • Underground drainage can be eliminated internally in the building - and can be significantly reduced externally - which can provide considerable cost savings and enhance construction programme on all sites, particularly contaminated ones.
  • For sites with a requirement for sustainable urban drainage (SUDS), siphonic drainage will allow water to be delivered at a designated point at shallow depth, which can significantly reduce the construction costs, especially for pond based solutions.