Can I use "in wall vent" instead of thru roof for shower?

[hawksnest]

I've used an in-wall type vent (air valve) for a toilet before instead of venting through the roof. Would it work for a shower?

Thanks in advance for your advice.

[Cass]

There is no "in wall" vent that I know of. There is a vent called an AAV (air admitance valve) that can be used but yuo can not put it in a wall.

[hj]

And at least one vent pipe has to be extended through the roof. You cannot use all AAV's.