Air Admittance Valve Under Kitchen Sink

If you ve ever tripped over a white mushroom shaped object up in the attic or seen a white cylindrical device under a kitchen sink that was probably an air admittance valve.

Air admittance valve under kitchen sink. This unit is well made and the instructions are clear and concise. If you live in such a community and your existing vent fails installing an aav is an easy alternative to. When there is a charge of water waste the air admittance valve will open and release the vacuum. Aavs cost around 25 and up depending on the size of the vent.

An air admittance valve is a valve that is completely pressure activated. The air admittance valve makes it relatively easy to install a new sink in an existing structure by making it unnecessary to find or add a vent line. These valves are gravity operated devices that respond to the negative pressure of draining water and open to let air in. Air admittance valves aav are one way vents installed after the trap on the drain line of a fixture.

Depending on the valve and the size of the vent aavs can support one or multiple vent lines. However before you begin installing an air admittance valve check with your local building inspections office as local codes govern the use of aavs in place of vents. Used most commonly at an island sink or vanity the vents are also located in the attic to prevent the roof penetrations as seen above on the front roof line elevation. Some communities allow you to vent sinks with an air admittance valve or cheater vent.

The wastewater being sent down the drain referred to as a slug pushes air in the pipe in front of it leaving behind an area of negative pressure. Loosen the couplers holding the p trap and female trap adapter onto the sink drain beneath the kitchen sink with a. Cut the 1 1 2 inch drain line into the wall just behind the coupler that is glued to the pipe with a hacksaw. Then gravity closes the valve keeping sewer gases out of the room.

Most of these valves are durable and long lasting if you encounter regular oatey sure vent problems then you need expert help as it may be an entirely different plumbing problem. One solution is an air admittance valve or aav. How to install an air admittance valve under the kitchen sink 1. Air admittance valves aka studor vents are negative pressure activated one way mechanical valves.

Studor 40170 20391 redi vent air admittance valve with tubular tee adapter 1 1 2 inch connection. You may have seen an aav before and not known it. They re designed to address negative air pressure in the drain system created when a fixture is drained.