An air gap is a device used in plumbing systems to prevent backflow of contaminated water from a sink or garbage disposal into the dishwasher. It serves as a physical separation between the dishwasher and the drain system.
Here's how an air gap works and why it is needed:
Backflow prevention: The main purpose of an air gap is to prevent dirty water from flowing back into the dishwasher. In the event of a clog or backup in the drain system, there is a risk of contaminated water entering the dishwasher and potentially contaminating the dishes. The air gap creates an unobstructed air channel between the dishwasher's drain hose and the sink's drain pipe, ensuring that water can only flow in one direction—away from the dishwasher.
Building code requirement: In many regions, the installation of an air gap is mandated by plumbing codes or regulations. These codes are in place to protect against cross-contamination and maintain proper sanitation standards in residential and commercial kitchens. Compliance with local building codes is essential for ensuring the safety and functionality of your plumbing system.
Alternative to high-loop method: The high-loop method is an alternative to using an air gap. It involves routing the dishwasher's drain hose to create a loop at a higher elevation than the sink or garbage disposal drain. The high-loop method aims to provide a similar backflow prevention mechanism by relying on gravity to prevent water from flowing back into the dishwasher. However, some building codes may require an air gap over the high-loop method due to its higher reliability.
In summary, an air gap is a crucial component of a dishwasher's plumbing system that prevents contaminated water from flowing back into the dishwasher. Its installation is often required by building codes to ensure proper sanitation and prevent cross-contamination between the dishwasher and the drain system.