AAV on "S" Trap

[Marcel Gratton]

Originally Posted by jallingham

Looks like they have to be installed in the horizontal part of the drain also, pretty much eliminating them from use on an S-trap.

7.5.9.2. Air Admittance Valves

(1)

Air admittance valves shall only be used to vent,

(a)

fixtures in buildings undergoing renovation, and

(b) installations where connection to a

vent may not be practical.

(2)

The air admittance valves shall be located,

(a) above the

flood level rim of the fixture it serves,

(b) within the maximum

developed length permitted for the vent,

(c) not less than 150 mm above insulation materials, and

(d) installed in a location not subject to back pressure.

(3)

Air admittance valves shall,

(a) only vent

fixtures located on the same storey, and

(b) be connected to the horizontal

fixture drain.

Something like in attached pic perhaps; but as Marcel C mentioned, only certain brands are approved in Canada.