I added a fume extractor today, really needed it.

[peppster66]

Hi, it seems we always had the issue of black tank fumes in the Roadtrek when were on the road with the windows open, it must create some type of a vacuum to pull the fumes out and into the cab, so after doing some research on the web, I realized its quite a common problem. Several people had really good luck with a product called 360 Syphon fume extractor.I ended up buying one from camping world for about $35.00, when I was in Florida recently, it was very easy to install, simple instructions, with a video on line also. I must admit it really does work well, ive been out cruising around with the windows down, and no more nasty fumes at all.If I understand it correctly, something about its shape helps to pull the fumes out of the vent pipe as your driving, .I took some pics to show it installed on my 97 Roadtrek, I did add some lap sealant around it and on top of the screws as well.i hope this may help someone withe same problem I had, I like these little projects, fairly quick and easy,,,, take care,,,,,, Josef,,,,

[markopolo]

I hadn't seen one like that before. It will keep debris out as well

[mkguitar]

Nice tip, my PW lexor stack is right be where my antenna parks- I'm going to climb up tomorrow and see if that syphon will clear it.

BTW gowesty is a good source for fiamma parts, end caps etc.

mike

[mkguitar]

GRRRR, not enough clearance for me- maybe I have to look at modding my antenna somehow to get some clearance for a syphon or venturi type fume sucker

mike

[peppster66]

I hope you can make it work up there, it really has made a difference for us, Im not sure if your experiencing the same issues we were, if so, this really seems to work well,,, take care,,,

[fwdanielson]

Did you screw directly in to the fiberglass top? I was looking at the same vent for our 95 Roadtrek and wasn't sure if the top was thick enough for the screws to get a good grab.

[booster]

I have a silly question, I think. How does a vent like that work when there is no source of air into the tank. All the drains have traps, and the toilet a flapper, so no air to vent with.

[fwdanielson]

It creates a low pressure at the top of the vent in order to keep air from flowing in to the tank (and your living quarters) when the toilet is flushed and also to extract any accumulated gasses from waste decomposing.

There are times when someone flushes the toilet in our RV without making sure there is water left in the bowl and it doesn't take long for the smell to let us know that happened so there must be some amount of air intrusion for that to happen.

[booster]

Originally Posted by fwdanielson

It creates a low pressure at the top of the vent in order to keep air from flowing in to the tank (and your living quarters) when the toilet is flushed and also to extract any accumulated gasses from waste decomposing.

There are times when someone flushes the toilet in our RV without making sure there is water left in the bowl and it doesn't take long for the smell to let us know that happened so there must be some amount of air intrusion for that to happen.

I understand the low pressure generation (obviously you need airflow over it for it to work). I could see how it could possible help when actually flushing, but that toilet is a big opening and awful close to the water level, so if parked I don't think you would have enough volume from the vent in normal winds. If you get smell with no water in the toilet, you probably have some stinky stuff on the flapper and seal, as it can't really be leaking because it holds water. We have had that happen in our Roadtrek. The OP was talking about getting smell inside the van when driving, so he would have to have some sort of a leak letting air into the van through an unfilled trap or leaking flapper. He also could have been sucking the smell back in through the windows after it came out the vent, and making it taller with the airfoil could change the airflow enough to keep it away.

Our Chevy Roadtrek just has a cutoff pipe out the roof about 1" high (now with a screen on it) and the only time we get any tank smell is if the floor drain trap goes dry or we have the windows open and odd wind conditions blows smell in from the roof vent pipe.

[peppster66]

I did screw it right into the fibreglass, I used 1/2" screws, and it came with the puddy for underneath, but I still added a bead of lap sealant around the rim, and on top of the screws. my biggest fear is getting a water leak, so I put it on fairly heavy,,,hope this helps...

[mkguitar]

Originally Posted by booster

I understand the low pressure

driving with the van windows open can cause a low pressure in the van, pulling in fumes from the tanks- even with water in the trap and toilet,


I have experienced gasses drawn through the trap....screwing in teh plugs and letting water sit in the sinks

another source I narrowed down to the in-floor shower drain- I pulled the plug and used teflon tape on the threads to get a better seal( we don;t use the shower).

many of the caps are made to be a venturi, drawing gasses up and out, some swing on a vane so will work when parked, the syphon shown above is made to work 360º ( as well as a swinger?)
and some only are effective if the air is moving inline with the length of the van ( driving or parked)- these are easily made with a home depot fitting.

my problem is my antenna is too darn close to the stack

mike

[booster]

I guess I just can't imagine getting enough negative pressure in a vehicle with the windows open to pull air through a trap, as there is so much open area in the window itself to balance. The numbers I have seen in the past were always well under .5 inches of water, usually .1-.2 inches and and I doubt that could pull air though a trap, especially with a negative on the tank from the blunt pipe at 90 degrees to flow on the roof. Trapless toilet with a bad seal, yep. But you never know.

[peppster66]

I really did try to fix the problem, I went through all my systems, , by making sure the floor drain was closed. I made sure there was lots of water in the toilet, and the flapper was not leaking, I even replaced the gasket between the toilet and the floor. I checked the kitchen sink to make sure the P trap was full of water, I cant tell where the fumes were actually coming from, but it was at its worst when we were on the highway with the windows down, It was very over powering , my wife was constantly complaining about it, that's why I ended up with the Syphon 360, I'm just glad its over, it really was not enjoyable on the long road trips in the summer time...........