venting for slow draining kitchen sink??

[Wingdreamer]

Just came back from my 7th camping trip out this season and came to the conclusion that I need to find a solution to the very slow draining of water from my sink. My own conclusion is that there is no venting, thus not introducing air to the line allowing the water to flow out of the sink and out the drain hose.
I know that one of the guys installed a larger diameter drain hose, which I will probably do as well, but still want to get the "physics" of the problem.

 My thought:  What about putting a tee in the drain hose line under the sink, and running a second hose up around the back of the sink (at least as high as the top of the sink). Drilling a small hole in the counter/sink area, maybe behind or beside the  tap, and feed this hose up through it.
Would this not allow air into the line after the actual drain in the sink and speed up the drainage of the sink? Simple and cheap to do, but should work.....
No difference than venting the plumbing in a house.....

Any thoughts on this idea? Anyone try this?

[He Ruide]

What about putting a tee in the drain hose line under the sink, and running a second hose up around the back of the sink (at least as high as the top of the sink). Drilling a small hole in the counter/sink area, maybe behind or beside the  tap, and feed this hose up through it.
Would this not allow air into the line after the actual drain in the sink and speed up the drainage of the sink? Simple and cheap to do, but should work.....

Wingdreamer, I've not tried this and maybe it should work.  However, as you said you will have to cut the drain hose, adding and secure a "T", reduce the "T" to add the small hose, bore a hole in either the sink or cabinet, and find some way to secure the hose so it stays in place. This solution is much more complicated than adding a vent on the OUTSIDE line or installing a larger hose or pipe.

My two cents worth.

Ruide

[coach]

Plumbing in my house goes down hill at all times. Takes the most direct/shortest route. May I suggest a short drain hose that goes down hill always, no hose laying on the ground that rises to a sewer connection or storage tank!
If you don't do that, then vent at the exit of the drain at the PU outside wall with a tee. The adhesion and cohesion/surface tension of water is strong, but nothing gravity can't handle (unless you drain with capillaries!)

[austinado16]

Just went through this because the 15 gallon blue tote was too tall to fit under the camper. So the drain hose was exiting the underside of the camper, making an "S" and going into the tote.  

I bought a lower 10gallon tot and now can park it directly under the drain fitting on the camper (under the floor, not out on the side wall).  In fact, the first time I used the new tote, I simply popped the 4" bayonette style cap off, and let the sink water fall from the camper into the 4" hole.  Worked great.

So for me, the solution taking out the "S" shape and from now on, I'll just have a short, straight piece of hose going right to the garden hose fitting on the tank.

[98sunridge]

What worked for me was to remove the white plastic trap. Get a 1 1/2
to 1/2 pipe coupler and a 1/2 street el  and a hose bob to fit your
drain hose.  This removes the safety of the trap and will allow sewer
gasses to enter when you hook-up to a sewer connection. I don`t
have a toilet hooked up to the drain. Only sink water going into a tote container. If you get a site with sewer, reconnect the trap.
My water goes down fast without even gigaling the hose.

[4Campers]

Just came back from my 7th camping trip out this season and came to the conclusion that I need to find a solution to the very slow draining of water from my sink. My own conclusion is that there is no venting, thus not introducing air to the line allowing the water to flow out of the sink and out the drain hose.
I know that one of the guys installed a larger diameter drain hose, which I will probably do as well, but still want to get the "physics" of the problem.

 My thought:  What about putting a tee in the drain hose line under the sink, and running a second hose up around the back of the sink (at least as high as the top of the sink). Drilling a small hole in the counter/sink area, maybe behind or beside the  tap, and feed this hose up through it.
Would this not allow air into the line after the actual drain in the sink and speed up the drainage of the sink? Simple and cheap to do, but should work.....
No difference than venting the plumbing in a house.....

Any thoughts on this idea? Anyone try this?

I have made up a 90 degree pipe out of simple 1/2" PVC. A hose bib connector attached to a 90 elbow, attached to a short piece of PVC pipe about 14" long. It can swivel on the camper hose connector, so placement of the gray tank is not critical. Only problem is when camped on a hill and the pipe can't reach the tank, but then I use a few 2 X 4's to raise the tank higher. I also cut the end of the pipe at an angle to eliminate back suction which slowed the draining. Best part is that when the gray tank gets full, the drain slows down and I know it's time to empty. With the pipe sticking into the tank about 4 inches, it never overfills. For the times when the slope is too much I simply revert back to my original idea and use a 24" piece of old garden hose cut off with the female bib attached. Sometimes the tank has to be positioned just right or the hose is to deep into the tank and slows down the draining.

[CAPEd CODger]

This is one solution to the problem......

http://home-and-garden.webshots.com/photo/1044112276037314420yrcuXU

http://home-and-garden.webshots.com/photo/1044112421037314420patDDU

Real easy to make and adapt for differing drain exits.... This one came out of the floor instead of the wall...

Best of luck

Happy Camping!

Bob

[BirdMan]

Does your drain hose on the side of your popup go all the way to the bottom of your drain can?  

If not, then the physics of this is pretty simple; air in the line has a greater force then the gray water in your sink trying to drain.  Once your sink gets about 1/4 to 1/2 full or when you pour water directly into the drain then it starts to drain by having enough force to push the air out of entire drain line.

I ran into a similar problem my first trip this summer.  Last year the drain worked great, but this past winter I had a bright idea to cut my drain hose shorter so it just fits into the top of the drain can.  My thinking is that as long as I heard the gray water splashing into the drain can it was not full and as soon as I heard no splashing I needed to go empty it.  I also thought, why have the hose getting all funky sticking down into the gray water and having to clean and dry it before I store it after a camping trip.  Sounded logical to me!

What I found out was that everything works great when you have the drain hose going all the way to the bottom of the drain can.  This creates a siphon effect by eliminating all the air out of the hose.  When you have any air in your drain hose it creates pressure and stops the sink from draining until you pour water directly down the sink drain to push the air out of the drain line.  I ended up re-attaching the length of hose I cut off and now the drain works great again

[coach]

the physics of this is pretty simple; air in the line has a greater force then the gray water in your sink trying to drain.

Where does air get this greater force?
I sure thought water exerted/exhibited/caused about .433 psi/ft ({62.4lb/ft-ft-ft}/{144 in-in/ft-ft}) and it took the entire atmosphere (miles) to exerted/exhibited/caused  14.7 psia. I may be wrong!

I'm sticking with cohesion/adhesion/surface tension as the cause for slow drains, like I previously stated, shortest direct route with the largest incline possible, smoothest pipe (inside) and the largest diameter or nothing at all.

I teed onto the hose bib drain, up to vent, down to bucket. I used 1/2", then I tried 3/4", I also plugged the vent. The time was exactly the same to drain 1 gallon. A tad slower than with nothing connected to the outside drain!

['tiredTeacher]

My thought:  What about putting a tee in the drain hose line under the sink, and running a second hose up around the back of the sink (at least as high as the top of the sink).
Any thoughts on this idea? Anyone try this?

Here's a way-too-simple solution that worked for me. Drill a hole in the drain hose, on top, right at the point it arcs downward. A 3/8" hole will let in air. Just be sure it's on top when you tighten the hose fitting. Voila! Problem solved.

OK - now back to the techies and their complex and expensive solutions. :sombraro:

[Wingdreamer]

Ok, to continue on with that last idea....What if you cut the ouside drain hose, just after it screws onto the side of the trailer, then simply install a good old fashioned rad flush tee??? loosen the cap and it will let air into the hose as it is draining.....make sure screw on cap is to the high side of the hose, just as it starts to go downward towards your graywater bucket.  You can tighten the cap and maintain the seal on the hose at any time as well.    hmmmm...... Gonna try that one when I go back out camping in 2 weeks..... let you know the outcome.  Thanks for your suggestions!  Alan

[jewlerman]

Alan, I read through all the posts here and was wondering if you hook your outside gray water hose into a campground septic or into your own portable collection container.

I only use an old 5gal. jug for collecting gray water and I had a problem with my sink not draining well in the past.  I figured out the same thing Birdman did about ensuring my outside hose went all the way to the bottom of my 5gal. jug. It seemed to have created a syphon effect and the water exited the sink normally.

Anytime I had any air leaks where the gray water hose connected to the trailer fitting or any part of the outside hose the sink would not drain properly.