Non electric SunMar Composting toilet help

[henrysaunt03]

Hello all,

I hope this is an ok question to post.  I've reviewed the conversation that occurred last summer on this site regarding these toilets, and am still stumped.

I just completed a renovation to a small seasonal cabin on a lake in central Maine.  No power.  I installed the SunMar non-electric which had been sitting in its box since its purchase in 1998.  Yup, that's how long these things take sometimes.  Anyway. 

I started using the unit on July 4th and I thought I followed all directions to the T.  By 3 days in, I thought I would pass out from the odor.  I opened the door and removed the finishing drawer (which had nothing in it yet) and saw a standing amount of urine about 3/4" deep in the bottom of the unit.  It isn't high enough to reach the overflow drain, and my God, it is beyond offensive.  Can this possibly be how it is meant to be?  I know some amount of liquid is supposed to gather in the bottom, and the venting is important (mine is straight up, no bends at all, and no fan, and it extends the recommended height above the roof line) to aid in evaporating that liquid.  However, it seems beyond belief to me that this is designed to have an inch of urine sitting in the bottom at any given time and yet people say there is no odor.  I can't figure out why the overflow drain is 1 1/2" up the back, and not in the bottom.  Also, there was an additional removable piece of hard black plastic farther back, behind the finishing drawer, about 12" by 8" and 3" high, with 4 feet, that I cannot figure out.  It is not described in the manual or shown in any pictures.  It was covered in urine as well.

What am I doing wrong??  I thought perhaps my ratio of wet/dry was off, so I've added a bunch more pine shavings and peat moss.  I soaked up all the standing urine, sprinkled baking soda, and left the windows cracked.  I won't be able to get back there for 2 weeks, and I'm pretty concerned that it will be a nightmare when I return.

Any help would be greatly appreciated!!!  Thanks!

[hpinson]

I'm curious what Sun Mar has to say.  Have you contacted their tech support?

If it continues to be a problem, don't hesitate to downgrade to a humanure system (bucket, sawdust, compost pile).  You'll very likely be happier in the long run.

[henrysaunt03]

Thanks, I have a call in to SunMar and I haven't heard back yet.  I'll post what they tell me.

[Pine Cone]

I have a Sancor Envirolet, but it is a dual-power one with options to us either a 12-volt DC or 120V AC

I also have a wind turbine on top of my vent pipe that looks like this.  Seems to work pretty well, doesn't take much of a breeze.


I think you will have fewer problems as the bottom tray begins to fill with composted poop.  The compost will wick up the urine and help it evaporate.

The only time we have had a problem similar to yours was when we had about 10 people for a long weekend.  The toilet could not cope.  The next time we had that many people I quietly encouraged several of the men to consider peeing in the woods.  Not the best solution, but better than having urine fill the bottom of the tray and then overflow...

[Squirl]

I haven't installed mine yet, and I'm not going with the self contained model.  I did a lot of reading on them before deciding to go with one as my alternative septic system on a difficult site.

My recollection was there were a few similar descriptions.

Some people had a back draft from their stack.  It didn't matter that they installed the stack to the right manufacturing height.  The design of the house or the land around it can change wind currents.  A very small number of people may still not get the right amount of ventilation because they are in a valley, or against a cliff, or the trees funnel wind down on their house, or any other number of reasons.  Some of the solutions were simply even higher stacks and/or more power venting.

A good way to find if you are getting enough venting is to hold a lighter up to the air intake.  If the flame is not drawn towards the intake vent, then you have a draft problem.  I got that from p. 19 from the owner's manual in the "Urine Odor in Washroom" section of the trouble shooting guide.
http://www.sun-mar.com/PDF%20Files/ExcelNEManual.pdf

Another issue is the standing urine.  That is the design for the model and most composting toilets.  With a good draft or power venting this is supposed to evaporate over time.  This keeps more black water out of the overflow.   This is important to some especially with many setback requirements of black water septic drains from features such as ponds and lakes.  There are many people are not fans of this aspect of composting toilets.  Some people have tilted the toilet slightly so more fluid drains to the back.  I have also read of people filling that area with things from diatomaceous earth, to sand, to pebbles, in an effort to displace more liquid.  If doing something like that, be sure not to clog the drain.

Sorry, over the internet, that is the best I can do to help you diagnose the problem.

[MountainDon]

I can not recall the last time I've seen any liquid in the bottom of our SunMar. (We have the self contained AC/DC model, but use it as an NE (non electric)). There are two of us; I must admit to seldom using the SunMar for my urine, unless it's simultaneous with a bowel movement. Or unless there is company present.

I did install the unit with a half inch slope from front to rear. It would appear that there has seldom, if ever, been any discharge out the overflow tube. The exposed section of tubing out the wall appears to be pristine. But I have never opened the cesspit it connects to to actually check.

My only complaints about the SunMar is my failure to realize the effect the cool/temperatures at 8800 feet have on the composting action.

Odors are not an issue either. I know our venting works well as I have been on the roof by the stack and have received quite a faceful of "brown" air from the top of the stack.

[henrysaunt03]

Thank you very much to everyone.  Sun Mar told me to take pictures of the installation and also of the black plastic piece and email them.  When I go back, I will do this, and I'll post them here too.  They said that the unit used to be designed with a black plastic tray but they eliminated it a few years ago because it didn't function as it was intended to, it just collected urine.  Since my unit was bought in 97 or 98, they think that's the explanation.  The rep said after she confirms it is the old design, I can probably chuck the black plastic piece.

As for the standing urine, yup, you are correct, it is indeed designed this way.  The rep said it should have 3/4" to 1 1/4" urine at any given time, and swears this causes no odor because it is pulled up the pipe.  She says the likely culprit of the odor, as you guys have suggested, is the draft.  I will try the lighter test.  (Thanks for providing that, the rep didn't suggest that!)  Perhaps the wind is pushing down the pipe because it is on an island, who knows, but the bottom line is something is interfering with the draft.  I will probably extend the pipe up higher than the 36 inches it already is.  And then pray.  I have been told not to put a turbine on it, because it can interfere with the draft (since it is NE).

So, again, thanks very much, and I will keep everyone posted.  Further thoughts welcome!!!

Amy

[Sun-Mar]

We are sorry that your experience with one of our composting toilets was not a good one.  Generally, if the toilet is maintained and installed correctly, they will operate in an odor free fashion..   We do recommend that you check the venting.  When experiencing odor on start up, it is generally because the venting is not installed correctly.   Check your venting to ensure there are no horizontal or downward sloping areas and that all connections are sealed with silicone.  Please contact us for a  current copy of the owners manual.  If you have any questions regarding the operation of your Sun-Mar composting toilet, please call us toll-free at 1-888-341-0782 ext 218.  We would be happy to assist you.  Your Sun-Mar service team. 

[hpinson]

Several inches of poorly vented standing urine is going to stink if it sits.

Can you test if there is airflow out of the vent stack - get up on the roof and hold some toilet paper - is there any draft?

Just a thought but could a tiny powered draw fan be installed at the end of the stack to pull air?  I know you said a turbine could impede airflow, but a fan that runs is different. I believe i've even seen some little fans that operate from a tiny solar panel PV direct.

[MountainDon]

The fan would have to run all the time though. If we're tsalking the 4" stack and if it is straight up it should work fine. Ours vents fine with NO fan. It's just cold weather that stops the composting.

[hpinson]

I had a similar thought Don after hitting submit.  I don't think it would take much of a battery to store power for those little fans - something like 0.5 amp draw. I even saw a kit at Harbor Freight the other day that could be used. Or just power from cabin AC if available.

Also, paint any exposed pipe black so it heats and pulls air.