Air Admittance Valve or vent stack for bar sink sump???

Finally getting serious about finishing my basement. Decided to add a wet bar but did not plan ahead during original construction and have no below slab drain line. I plan on using a small sump basin and pump and have installed a line to the main floor kitchen drain plumbing.
I have used Studor AAV’s in my kitchen and utility rooms and have used Rex Cauldwell’s book as a reference for all my plumbing. My main concern is the sump building up pressure due to the fact it will never be 100% empty and creating an odor problem that the AAV may not control.
I can rough in a 1 1/2″ ABS vent stack before I drywall the basement ceiling but I my only option is to go out the rim joist and towards the front of the house. This will be ugly and potentially smelly as well.
Any input appreciated. Thanks!
Replies
For what it's worth i have a neighbor whose basement was finished. His bar sink and bathroom sink both drain into a "Sanicompact Systems" macerating toilet. See it about halfway down on:
http://www.plumbingsupply.com/maceratingtoilets.html
According to the description
The Sanicompact system does not need to be vented or connected to a vent stack
One optional 1 1/4" inlet for addition of a hand basin
The last bullet suggests that he's only supposed to have 1 not 2 added items draining into it.
I'm sure your not going to add this as a solution but I mention it because here's a non vented pumping system. The larger systems on the page do require a vent.
I am considering doing the same as his in my basement.
For what it's worth i have a neighbor whose basement was finished. His bar sink and bathroom sink both drain into a "Sanicompact Systems" macerating toilet. See it about halfway down on:
http://www.plumbingsupply.com/maceratingtoilets.html
According to the description
The Sanicompact system does not need to be vented or connected to a vent stack
One optional 1 1/4" inlet for addition of a hand basin
The last bullet suggests that he's only supposed to have 1 not 2 added items draining into it.
I'm sure your not going to add this as a solution but I mention it because here's a non vented pumping system. The larger systems on the page do require a vent.
I am considering doing the same as his in my basement.
The AAV would prevent the pump from siphoning the trap. It wouldn't (as you and others observed) prevent pressure buildup, either from inflow prior to the pump kicking in, from backflow through the discharge pipe after the pump shuts off, or from biologic action in the sump pit.
I'm no plumber, but under those circumstances I'd really like to see a "real" vent.
It would be best, as you say to have a vent, especially one to vent the sump basin itself, because that's where backpressure will happen.
A vent that terminates thru the rim joist would probably be best, since the water level in the sump would always act as a trap. Any odors would be those from the sump basin itself, not the sewer system.and would not be objectionable outdoors.
It wouldn't be impossible to add the vent stack, just a PITA and an eyesore until the landscaping matures. No problem at all really, and the more I think about the odor possibility I guess it makes sense to just do both.
Thanks!
Very likely code requires that the pit be vented.