Learn About Air Admittance Valves
By: Samantha Green
Read more to learn the basics of air admittance valves (AAVs) and when it is best to install one in your own home.
Venting is an essential part of any plumbing system. It prevents smelly, dangerous gases, like methane, from entering your home . Proper ventilation also equalizes air pressure in your pipes so they drain properly. Air Admittance Valves work as a one-way venting system. It lets air into your drain system, when there is negative air pressure.
AAVs work with the help of a rubber sealing mechanism that is lifted to let air into the drain system. Positive pressure causes the mechanism to close so that gases cannot escape into the home. Most homes vent directly through an opening on the roof of their house. Sometimes structural blockages or multi-stories won’t allow a vent to be placed on the roof line. In those cases, air admittance valves are another option to consider.
Noisy, gargling sinks and slow draining toilets are a good indicator that your home needs an improved venting system. AAVs can greatly reduce the amount of venting materials in a plumbing system and are generally maintenance free.
Most plumbers recommend this kind of mechanical venting system for kitchen islands, when there is a large window above a sink or wherever a traditional vent would be problematic.
Before installing an air admittance valve to your plumbing system, check with your local building department to ensure using an AAV in your home is up to code.