Septic vent charcoal filter installation

[chrisvt]

We need to install a charcoal filter on our septic vent pipe and I'm struggling to determine where I should locate it.

The normal installation locations (on the roof, or an in-line type of filter in the attic) are problematic due to unsafe access; we have a very tall two-story house, and the attic is a truss system with blown-in insulation and minimal headspace.

Stating the obvious here, but our main vent pipe comes through interior walls before getting into the attic. Once in the attic, two smaller vent pipes (one from the second floor shower and one from the second floor laundry) tie into the main pipe before it exits the roof.

Would it be a bad idea to install the filter on only the main pipe, obviously above all the drain locations, but prior to it going into the attic and before those other smaller vents tie in to it? Would there be any back pressure issues given that the two smaller vent pipes would tie in the the main vent pipe above the filter? We'd obviously need to cut the sheetrock on an interior second floor wall, but that isn't an issue because it would be in a closet.

 

[JG plumbing]

Can I ask why you need this?

 

[chrisvt]

Can I ask why you need this?

We've been experiencing sporadic septic smells on the deck and in the yard. Sometimes the front of the house, sometimes in the back. It doesn't seem to matter the time of day or year.

The house and septic system were new as of 2017, and my first thought was that there was something wrong with the system. Both our septic engineer and plumber have confirmed that the system itself is functioning properly, and concluded that the smell was due to the air flow around the house; the house itself is built on a slight side hill, and there is a small knoll to the north (windward) side. They suggested the charcoal filter solution.

 

[Twowaxhack]

I’d wait until I smelled it strong one day then cap the vent.

Dont use any plumbing inside.

See if the smell goes away while the vents capped.

Just to make sure that’s your issue.

 

[SHEPLMBR]

We need to install a charcoal filter on our septic vent pipe and I'm struggling to determine where I should locate it.

The normal installation locations (on the roof, or an in-line type of filter in the attic) are problematic due to unsafe access; we have a very tall two-story house, and the attic is a truss system with blown-in insulation and minimal headspace.

Stating the obvious here, but our main vent pipe comes through interior walls before getting into the attic. Once in the attic, two smaller vent pipes (one from the second floor shower and one from the second floor laundry) tie into the main pipe before it exits the roof.

Would it be a bad idea to install the filter on only the main pipe, obviously above all the drain locations, but prior to it going into the attic and before those other smaller vents tie in to it? Would there be any back pressure issues given that the two smaller vent pipes would tie in the the main vent pipe above the filter? We'd obviously need to cut the sheetrock on an interior second floor wall, but that isn't an issue because it would be in a closet.

If this is problematic for you to do, I suggest getting someone to do it for you.

 

[johnjh2o]

Try extending the vents a little higher. You may be getting a downdraft from the airflow off the roof.

 

[Twowaxhack]

I had a business with this problem and it ended up being the city’s manhole, being on septic, this couldn’t be your problem unless sewer is available and you’re not connected.