Side vent for gray tank venting?

[John in Michigan]

For gray tank venting, does anyone use a side vent instead of a roof vent?

My Boler 17 currently has the factory installed setup: a large plastic vent pipe extending from sink drain pipe up though the countertop and then up through the roof. When I re-do the kitchen, I would like to replace this vent pipe with a side vent pipe just under the countertop extending through the side of the camper. I am thinking I could use a small marine type side vent cap to ventilate gray tank gas accumulation, and then if more ventilation is needed for draining the gray tank, I could add an air admittance valve under the counter.

(The current gray tank and vent described above also serves the shower drain.)

Thoughts??

[John in Michigan]

... of course gray tank venting is also needed as gray water drains into the tank.

[David B.]

Lil Snoozy uses a side vent for their gray water, just below the belly band.
Dave & Paula

[John in Michigan]

Dave&Paula, thanks for the feedback! Any idea as to the size or type of exterior vent? Do you know whether there is also air admittance valve inside the camper? Also, have you noticed any downside to the side air vent such as slow draining or occasional odors? Thanks again.

[floyd]

Scamp vents the gray tank through the floor with a simple loop of tygon tubing.
Black water tank is vented through the side wall.

[John in Michigan]

Floyd, thanks for the feedback. What sort of through hull vent is used for the black water tank?

[David B.]

Originally Posted by John in Michigan

Dave&Paula, thanks for the feedback! Any idea as to the size or type of exterior vent? Do you know whether there is also air admittance valve inside the camper? Also, have you noticed any downside to the side air vent such as slow draining or occasional odors? Thanks again.

John, I have had no problems with slow drain, and no odor. The piece is an
ATTWOOD D31472 5/8” fuel vent. You can purchase it for $7.45 from waveinn.com. I don’t know what an air admittance valve is.
The 3rd photo is a what it looks like with the cover screwed off...some kind of screen built into the vent.
Dave & Paula

[John in Michigan]

Dave&Paula, thank you for the details. Very helpful. Is the vent located near the kitchen sink?

[John in Michigan]

An air admittance valve is a one way valve that can relieve negative pressure in a drain pipe. Usually installed just downstream of a sink. Using air admittance valves, one can reduce the number of vent stacks needed in a house or any building.

[David B.]

Originally Posted by John in Michigan

Dave&Paula, thank you for the details. Very helpful. Is the vent located near the kitchen sink?

It is located opposite side of the trailer from the kitchen sink, just outside the shower wall. P.S. We will be in Michigan this August, do you know if there will be a FGRV gathering in the U.P. again this year?
Dave & Paula

[John in Michigan]

Dave&Paula, I don't know anything about the UP gathering. I do know that the 2019 Algonac gathering is scheduled for the first weekend after labor day. I plan to be there.

[floyd]

Originally Posted by John in Michigan

Floyd, thanks for the feedback. What sort of through hull vent is used for the black water tank?

It is a simple PVC pipe directly off the back of the toilet. It has a simple plastic round vent cap which is flush with the outside of the hull.
Look close just below the stripe and above the front side light....




It looks similar to this...

[John in Michigan]

Thank you Floyd. Very helpful in sorting this out.

[Eddie Longest]

Scamp sells the little vents but you have to call them. I had difficulty locating one for a toilet install.
Eddie

[GlassCastle]

I found when I crank down the front of the camper water drains much faster from the grey tank.

[ldsharp]

I had a 2014 Casita Standard (no bathroom). Casita mounted the gray tank vent as high as they could inside the galley sink cabinet. That put it just under the belly band. It was about a 4" white plastic vent. The sink drain went through a J trap and into the center of a tee near the side of the cabinet. The lower part of the tee went to the gray tank and the upper part of the tee attached to the grey tank vent with a flexible hose.

[Seaross]

Hi John, I used a boat output drain on the side of my trailer for the black tank while I completed a bathroom , where I had the two bunk beds in front of the trailer.
Check my blog for details.
http://www.fiberglassrv.com/forums/f...tml#post699794