Internal ventilation network
Disposal of wastewater, black water and rainwater in single-family homes

If there's no downdraft ventilation on the wastewater system, this lack of ventilation can create a strong negative pressure when a large mass of water passes through the drainpipe, which sucks the water out of the siphon. As a result, unpleasant odours are no longer blocked, but rise up and spread throughout the room.

To eliminate desiphonage, a ventilation system (external air intake) is required to compensate for the draught produced in the pipes.

Ventilation must always be positioned upstream of the body of water generating the negative pressure in the pipes.

This mainly concerns houses or housing estates of between 1 and 20 population equivalents. In this case, it depends on the ministerial decree of September 7, 2009, modified on March 7, 2012.

Since 2006 and the new law on water, regulations...