360 Siphon Extractor Vent Cap

[HoosierB]

Has anyone replaced their holding tank roof vent cap with a Lippert 360 Siphon Vent Cap? Claims to extract tank odors with as little as a 2.5mph breeze. Any installation tips and performance results would be welcome.

[Blue~Go]

I've never used one, but on the other hand, I wonder how any vent is going to "extract" tank odors. What I mean is that they do vent tank odors, but it's not like you can remove all the smell from a sewage tank - it's always gonna be there because it's a .... tank of sewage.

From my understanding a vent is to allow sewage gases to escape (vs. build up and your tank explodes), and/or to admit air so that water can drain (depending on how things are set up - eg our kitchen sinks have "air admittance valves" so they admit air a different way because they are not connected directly to a vent stack).

(I've seen posts where people have sewage odor in the rig and thus think that the solution is to remove sewage odor from the tank somehow, but as I understand it "sewers are gonna be sewers" and the way to avoid odors is to maintain a trap (water traps in our case; but something like a Hepvo trap can also be used).

Maybe there are situations where the tank vent is convoluted or blocked and so a "power vent" is needed? Or there's something I'm not getting about it. Maybe there could be a situation where siphoning could occur or something? With my [perhaps limited] understanding of how plumbing vents work, it could just be that there is something I don't understand. My experience is either on houses, which don't move, or boats, which move but generally under 30 miles-per-hour. Those don't seem to need any help venting as long as there is not a big design flaw in the plumbing.

BG

PS: I actually think the reason I was getting sewer odor into my shower drain when I was traveling was either siphoning or "jiggling" in the shower trap because it's really close to the tank level, but I'm not sure a power vent would solve that. I wish I had easier access to the shower trap so I could replace it with a Hepvo type. I think that would take care of it.

[HoosierB]

BG... I was wondering the same, hence my post. Apparently under certain conditions a "back pressure" may be created causing the gasses to blow back into the coach.
I was considering this mod as more "preventive maintenance" than anything else since my vent cap needs replacing.

Here is the Lippert Components product explanation:
The 360 Siphon® RV holding tank vent cap remove odors from the source — the holding tanks — and exhausts them out the roof vent before they have a chance to invade the RV living space. By design, the patented 360 Siphon can only create an updraft, expelling odors and fostering an oxygen-rich environment to speed up waste breakdown. Even environmentally-friendly tank additives can take up to 48 hours after use to fully oxygenate a standard holding tank. The 360 Siphon acts immediately after installation in any wind condition (with or without a breeze) to provide the ideal environment for proper decomposition, so caustic chemicals and perfumed cover-ups are no longer needed.

RVGeeks did a good video as well:
https://www.youtube.com/watch?v=3xX60cCHwlM

[A Rooney]

I bought one a year ago but have not yet installed it because,odors have not compelled me...that computer geeks video was compelling.there is a certain physics to updraft,for instance a fireplace has to have a smoke shelf at the base of the flue to draw smoke upwards rather than into a room...in the video they use smoke to demonstrate the siphon 360 effectiveness...which is to say. I cannot add anything constructive to the conversation...but as usual that has not stopped me from posting.Rooney

[Blue~Go]

Not sure I get the part where they say it pulls smells out so they don't backdraft into the coach. How can they "backdraft" through the water that is in your traps? I mean if ANY smell could get through water everyone's house/RV/kitchen/bathroom would stink to high heaven.

I guess the one place I could maaaaybe see it would be when you flush the toilet, since most RV toilets are really just an outhouse when you open the flush mechanism (i.e. pipe straight into a hole of excrement). There is no trap in the sense that a normal sink or toilet has one (U-shaped pipe full of water). Instead, the water that normally sits on top of the ball (in the bowl) functions as the trap. Odors can't get through that, but of course when you flush that is opened (on the other hand, few flush when driving). I've still never used any tank chemicals. I just make sure not to have the bathroom roof vent fan on extract mode (sucks the smell up and in).

I guess I'm a bit skeptical.

[Rokrover]

I just replaced my aging and rather ugly “Cyclone” sewer vent and researched several options. I did look at the Lippert Components #389381 360 Siphon Roof Vent but not all reviews were positive. Problems claimed were brittle plastic and trapping water. Personally I thought the “siphon” claim a bit gimmicky, just like the supposedly innovative “cyclone” design.

So in accord with my ‘back to basics’ theme I ended up with the generic American Hardware Plumbing Cap #V-015C. It is all metal, low profile and only $7. It uses 5 #8 1” screws and fit perfectly after I cut the inner black ABS vent pipe 1” shorter. There was a void under the roof line where the pipe exited that I filled with styrofoam insulation.

[Scott]

The device is a bit silly. If it fixes something, then there are other problems in the system. Water traps are very good at what they do. (Yeah, some of the older toilets have an overflow that doesn't hold much water, but you can purge that with a small bottle of water). The only thing I would worry about with the roof seal for the vent stack is that it's weather-tight. If it leaks, it's in a spot you would probably not check or notice.

[pdemarest]

I put one on my rig after the initial post, mostly because the old cap was knocked off by a tree branch that ran in front of me (also cracking my A/C shroud - those darned branches!). Can't tell if there's any difference because I didn't have any sewer smell before but it appears that it will keep the rain out.

[HoosierB]

FYI update: Plastic is not brittle. Very well made. No evidence of water leaking. It works. It's a vent cap of improved design... simple upgrade replacement if OEM is trashed.

[daltonbourne]

These were the best accessories I ever put on my 30 ft RV, which is the Camco Cyclone Rotating Sewer Vent. This product uses surrounding air to ensure foul odors get vented out because this model follows the wind’s movement through rotating an incredible 360 degrees. This cyclone RV vent has an easy installation process. I can instead attach this product using a sealant. I was thrilled to see this product offer some choices concerning its color scheme. It ensures buyers can choose an option capable of meshing with their rig’s roof without issues.