(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)
Air admittance valves shall be located
(a)
not less than 100 mm above the fixture drain being vented,
(b)
within the maximum developed length permitted for the vent, and
(c)
not less than 150 mm above insulation materials.
(3)
Air admittance valves shall
(a)
only vent fixtures located on the same storey, and
(b)
be connected to the horizontal fixture drain.