2021 nuCamp T@B 400 Boondock - Installing a SunMar GTG Dry Toilet

krsmes

2021 nuCamp T@B 400 Boondock - Installing a SunMar GTG Dry Toilet

Components:

• SUN-MAR GTG COMPOSTING TOILET || Portable Toilet, Compost Toilet for RV
• Sealproof 1.5" Pool Filter Pump Connection Hose for Above Ground Pools, 1-1/2 Inch ID Dia x 59" Premium Quality Kinkproof PVC
• Supply Giant 6I78 Flexible Tee Coupling 1-1/2'' Inch Black with Stainless Steel Clamps, 1 1/2 inch

Installed prior to ever using the black tank.

Removal of the existing flush toilet:

Ventilation work:





12v power wire:





Toilet install:









(additional bolt in the back to keep it from tipping forward)


Why the SunMar? Yes, it is an overpriced bucket but compared to the alternatives considered (nature’s head, villa, air head) it doesn’t pretend to “compost” which none of them actually do (no one is going to keep waste material in their toilet for 6+ months) - even though it is still in the name.  It is better referred to as a dry toilet (simply separating the wastes and venting the solid wastes dry).  The models that pretend to compost have handles to churn which prevents the use of liner bags — this makes cleaning the waste bucket a messy job, opposite of my reasoning for wanting to switch to composting (in addition to a better true-boondocking solution).  

With this SunMar we use compostable 6-8 gallon bags for the solid wastes, sprinkle with coco coir, layer with coffee filters and simply remove the bags when necessary.  Everything remains spotlessly clean.  We’ve used this setup for a few trips over several weeks and have had zero odor.  Very happy with the simplicity and cleanliness - even though it is ridiculously priced for what it is.

Final cleanup (minus the shower curtain which hangs nicely in the corner behind the toilet when not in use):



krsmes

Meant to update this earlier... last fall I upgraded/hacked this system so that the liquid waste goes into the black tank.

Over the past 15 months we've been extremely happy with this setup... except for one thing.  And it is the same one thing you hear from everyone that has a "composting" toilet--- the pee bucket needs emptied every one to two days.

The system itself is great-- it allows for extended boondocking/dry-camping as lets us use all our water for washing instead of flushing half of it literally down the toilet.  In addition to the benefit of not having to deal with the waste in the black tank.

Every time people see it the first question is about whether there is any odor -- and there is not.  Zero.  The only time there has every been an issue is when liquid waste spills into the solid waste bucket.  And the solution is pretty simple, tie up the solid waste bag and put a new one in.  As shown in the install there is a fan running 24/7 venting the toilet to the outside (and no, there is no outside odor either).

So to deal with the limited liquid waste capacity of the toilet...  it is sitting right on top of an unused 12 gallon black tank, so why not make use of it?

So I took out the toilet, and the drain cover I had installed in the above instructions...


and hacked together a drain pipe system in the toilet itself to connect into the black tank:


Not shown here is the adapter to the 3 inch opening that I created sitting under the toilet.


We now use the front part of the toilet for yet more storage, such as two containers of coco coir for our composting material.



From the outside it looks exactly the same as before. 

Now we can go 10-14 days before having to empty the liquid waste instead of an almost daily activity.  And it just simply drains out the black tank drain with the gray tank.

Perfect water-less "hybrid" toilet.

gande

@krsmes…
Every time people see it the first question is about whether there is any odor -- and there is not.  Zero.  The only time there has every been an issue is when liquid waste spills into the solid waste bucket.  And the solution is pretty simple, tie up the solid waste bag and put a new one in.  As shown in the install there is a fan running 24/7 venting the toilet to the outside (and no, there is no outside odor either).

How does the odor dissipate?  There is odor initially, as we all know. If there is no odor inside, and no odor outside, where does the odor go? Is there some sort of chemical treatment?

If there is a fan running 24/7, what is the electrical draw of this fan, and what is the impact on battery life?

Thanks, 

gande

krsmes

gande said:

How does the odor dissipate?  There is odor initially, as we all know. If there is no odor inside, and no odor outside, where does the odor go? Is there some sort of chemical treatment?

If there is a fan running 24/7, what is the electrical draw of this fan, and what is the impact on battery life?

I'm sure there is odor on the outside but it is dissipated into the great outdoors and not something a human can detect standing outside the trailer.  Adding the coco-coir material to the solid waste also helps eliminate any moisture quickly which reduces initial odor too.

The premise of dry/composting toilets is that by keeping the urine out of the solid-waste you eliminate the "sewage" aspect and most of the associated odor.   https://en.wikipedia.org/wiki/Urine_diversion "a mix of urine and feces causes substantial odour" -- I was skeptical but after a year+ it has shown to be accurate.

The fan is just a 12v 40mm quiet computer-case-type of fan drawing about 0.5w (0.05a) so it is negligible (~1ah/day).  It can be seen (sort of) in the third-last picture from the original post

krsmes

Since the above March 2022 post where I connect the liquid waste to the black tank I have replaced the 1.5” PVC pipe, visible in the 3rd picture, with a one way trap

Wavin BV1B/UB HepvO Sanitary Waste Valve - 1-1/2" https://a.co/d/dVvqOxN

This stopped the toilet’s fan from pulling air from the black tank. 

slmarchap

@krsmes
Thank you for the detailed and updated dry toilet installation processes.  It looks great!  We hope to be installing the OGO brand dry toilet in the spring.  I sure appreciate your detailed pictures of how you tapped into the existing vent pipe behind the sink! 

As I look at the pictures that you posted with wiring, it looks like the 12v wires for the fan of your unit lead towards the bed area.  We have a 2020 400BL and I know that there were several design changes and added outlets in your newer 2021. Is the photo that you labeled "12v power wire" located in the bed area near the vent or is it in the front of the camper near the front vent?  I'm trying to get an idea of where I will be able to tap in to the 12v system for fan and agitator power of the OGO.   

Thanks in advance!