Camper plumbing vent question

[VortecJeep]

Building a toyhauler with a bathroom. It will have a sink, shower, and toilet. The toilet will go into a small black tank. The black tank will then dump into a portable tank on the ground. The sink and shower will go straight to the portable tank.
Do I have to run the vent above the roof? Could the vent line make a u-bend above the water level and then exit out the floor?

 

[GotWood]

They make a vent that goes under the sink. Has a check valve or something like that.

 

[rockcity]

You will need to vent out the roof. This is the primary vent. You can use studor vents under the sink for local venting.


Most states require at least one main vent through the roof of a residence with the option of using studor vents at fixtures. Some allow a studor vent as primary vent, but they are limited and require other venting provisions, which I don’t know right off hand.

I realize this is on a camper, but the logic should be the same.

I have 3 studor vents at the fixtures in my RV AND 3 roof vents.

 

[VortecJeep]

You will need to vent out the roof. This is the primary vent. You can use studor vents under the sink for local venting.


Most states require at least one main vent through the roof of a residence with the option of using studor vents at fixtures. Some allow a studor vent as primary vent, but they are limited and require other venting provisions, which I don’t know right off hand.

I realize this is on a camper, but the logic should be the same.

I have 3 studor vents at the fixtures in my RV AND 3 roof vents.

Do you know if the roof requirement is just for the smell? If the vent is to replace the air when you drain, it seems like it could suck air from places other than the roof.

 

[rockcity]

I’m sure it has to do with smell. Camper tanks get hot. When that gas expands, it has to go somewhere. If your only vent is a studor vent inside the camper, well, your gonna end up with a smell inside the camper.

and technically, studor vents are 1 way vents. A true vent for the system should be open to atmosphere all the time.


It may work and you may be fine. But I wouldn’t do it. There has to be a good reason RV manufacturers put roof vents in and studor vents.

 

[VortecJeep]

I’m sure it has to do with smell. Camper tanks get hot. When that gas expands, it has to go somewhere. If your only vent is a studor vent inside the camper, well, your gonna end up with a smell inside the camper.

and technically, studor vents are 1 way vents. A true vent for the system should be open to atmosphere all the time.


It may work and you may be fine. But I wouldn’t do it. There has to be a good reason RV manufacturers put roof vents in and studor vents.

.
Thanks for the info. Could I go out the vent in the side near the top of the wall? I just got the bathroom framed in today. If that won’t work, I’ll cut a hole in the roof, but hoping not to have to do that.

 

[rockcity]

I guess you could go out the side. Not really sure.

 

[tsconver]

You could make a big upside down u and go out the bottom. If just needs to allow air in.