ok,so I'm "venting challenged" 
here's my proposed set-up and questions:
the downstairs 1/2 bath that I'm going to build will be draining into the stack in the pic. a sanitary tee will go into that ci hub and provide the drain. the toilet will be a "Gerber" rear outlet toilet and the sink will drain into a 1 1/2 line connected to the 3 in. toilet drain. there will be an AAV installed on the 1 1/2 in. line right after the sink "p-trap" for venting. (a plumber told me to do it that way) now the questions: the AAV works on vacuum in the pipe as water attempts to drain,right? I can see how that AAV will open when the sink drains but my question is whether it opens when the toilet flushes or does the toilet rely on the "stack" venting? (I believe that "stack" goes up and through the roof)
tnx,
here's my proposed set-up and questions:the downstairs 1/2 bath that I'm going to build will be draining into the stack in the pic. a sanitary tee will go into that ci hub and provide the drain. the toilet will be a "Gerber" rear outlet toilet and the sink will drain into a 1 1/2 line connected to the 3 in. toilet drain. there will be an AAV installed on the 1 1/2 in. line right after the sink "p-trap" for venting. (a plumber told me to do it that way) now the questions: the AAV works on vacuum in the pipe as water attempts to drain,right? I can see how that AAV will open when the sink drains but my question is whether it opens when the toilet flushes or does the toilet rely on the "stack" venting? (I believe that "stack" goes up and through the roof)
tnx,
