Air Admittance Valve (AAV)
#1
09-06-20, 11:09 AM
Air Admittance Valve (AAV)
I am installing a bar sink in a finished basement and also a utility sink in the unfinished portion of the basement. Both will drain into a drain pump kit. The pump will lift the water up into the main sewer line. Where should the AAV be placed...under the sinks or on the drain pump lid? Tks!
#2
09-06-20, 11:31 AM
Group Moderator
If you've gotten the pump and tank kit..... there should be a vent line in the top of the tank cover.
#3
09-06-20, 02:05 PM
I've not bought the pump yet, but I have seen youtube videos of the lid with 3 holes. The reason why I raised this question was that the pump will be around 10' away from the bar sink. Would it make much difference on how the sink drains with the AAV that far away?
#4
09-06-20, 02:09 PM
Group Moderator
#5
09-06-20, 05:18 PM
Two separate questions:
1) Technically you need 2 vents. Since the trap arm (drain) is more than 6' (assuming 1.5" drain), you'll need to vent the drain at the sink.
Next, you need to vent the pump box. The problem with using an AAV is that an AAV allows air in, but not out (don't want those sewer gasses in your house). As water goes into the pump box, the air displaces and needs to go out. The AAV doesn't help with that. So typically, an AAV won't work in a pump box. Not that people haven't tried of course.
Now Studor does have a design for getting an AAV to work with an ejector pump, I've never seen this done, but it might be something to consider. Studor Design Manual (see page 30)
1) Technically you need 2 vents. Since the trap arm (drain) is more than 6' (assuming 1.5" drain), you'll need to vent the drain at the sink.
Next, you need to vent the pump box. The problem with using an AAV is that an AAV allows air in, but not out (don't want those sewer gasses in your house). As water goes into the pump box, the air displaces and needs to go out. The AAV doesn't help with that. So typically, an AAV won't work in a pump box. Not that people haven't tried of course.
Now Studor does have a design for getting an AAV to work with an ejector pump, I've never seen this done, but it might be something to consider. Studor Design Manual (see page 30)
#6
09-06-20, 08:05 PM
Thanks for the information - very interesting.
#1 - yes, I'm using an 1.5" discharge pipe so I'll install the AAV vent under the sink.
#2 - I'll get those instructions printed off from Studor's Design Manual and try to decipher what it's stating. I'll probably get back with you.
Mike
#1 - yes, I'm using an 1.5" discharge pipe so I'll install the AAV vent under the sink.
#2 - I'll get those instructions printed off from Studor's Design Manual and try to decipher what it's stating. I'll probably get back with you.
Mike
#7
09-07-20, 01:35 PM
Zorfdt....Studor pg 30 explanation doesn't look too complicated. Basically looks like the venting goes back into the main sewer with the AAV attached midway on the riser pipe. Thanks for the info.
