What purpose do relief vents serve in multi-story buildings?

Relief vents in multi-story buildings play a crucial role in balancing fluctuating pressures within the plumbing system. As wastewater flows through the drainage pipes, it can create varying levels of pressure due to the movement of water and the presence of air in the system. If these pressures are not properly balanced, it can lead to issues such as siphoning or the formation of vacuum conditions that might impede drainage efficiency or cause traps to be emptied, allowing sewer gases to escape into the occupied spaces.

By incorporating relief vents, the plumbing system allows air to enter or escape, which equalizes pressure differences and ensures smooth, uninterrupted drainage. This function is vital to maintaining proper flow rates and preventing potential problems associated with pressure imbalances, such as slow drainage or backup situations. In summary, relief vents are essential for maintaining the operational efficiency and safety of the plumbing system in multi-story buildings by ensuring that pressure is appropriately balanced.