Grey tank venting

[islandtrader]

I just discovered on my full monty re-do that I forgot to run a spot for grey tank venting.

The tank is vented, and it is to far away from the black tank to tie in.

My question is this? Can I run a smaller vent tube and run it thru the wheel well? Or someplace else besides the roof area?

[AirMiles]

You probably can use a studor vent. This is how island sinks are vented in homes.

https://www.youtube.com/watch?v=Ll9dHYWFVrY

[JayTheCPA]

While not touching any code aspects and will defer to better experts...


Going with the wheel well location should work from a functional perspective, although it might perfume the surrounding air. In the pleasure boat industry, it is common to vent along the gunnel.

Toward sizing of the vent pipe, the smaller the pipe, the slower the waste water will flow when dumping. So, might consider using no smaller than the OE size.

[A W Warn]

A Studor vent will not work in this case. As the tank fills there is positive pressured air that needs to go outside. An air admittance valve is a one way that only allow air in when the tank is draining, but not out when the tank is filling.
Jay covered the rest of it pretty well! Go through the roof is best for air quality.

If there is a convenient location where the pipes are near each other, the gray tank vent can be connected to the black tank vent so that there is only one penetration through the roof.