What is the function of a vent system in plumbing?

The function of a vent system in plumbing is primarily to prevent sewer gases from entering buildings. Vent systems are essential for maintaining proper air pressure within the drainage system; they allow for the escape of gases that can accumulate in waste lines. When waste is flushed through the plumbing system, a vacuum can occur if there is no venting, potentially causing slow drainage or even siphoning the water from traps. This could allow harmful sewer gases to enter the living space, which is a health hazard.

By providing a pathway for these gases to vent outside, the vent system not only protects the health of occupants but also ensures that traps remain filled with water, which serves as a barrier against sewer gases. Thus, the vent system is a critical component in maintaining safe and effective plumbing within buildings.