Compost toilets for buses

[Brent uk]

Hi I'm a Brit. I've been following the veggie oil discussion and I like the way that people just try something out and then post what they have done. I 've got a similar interest in mobile composting toilets. I know its a bit odd!
I've seen some (expensive) american ones designed for buses at around a thousand bucks but anyone tried to make or adapt one? I've had a (brief) look around the site and there doesnt seem to be anything about compsting toilets at all.

 

[Steve-SKO]

From all of the discussions I have seen on it, its a bad idea. It takes a long time for it to compost and can smell bad out of the vent.

If you use the toilet just a day or two at a time yourself it would work, but just in a weekend a family of four would produce so much material that it would never work.

 

[soused moose]

No offence meant …but yes you can install a Composting toilet in your rig. As long as you know what you’re doing (Toilet Use) and install the vent pipe system and such correctly they don’t smell at all.
Actually Composting Toilets if used correctly have no nasty smells…where an RV toilet & Black Water tank system stinks under some conditions (Bad Venting, rotten toilet seals etc.)
As far as capacity goes….Good composting Toilets like Sunmars Excel-NE (non-electric) has more than enough capacity for daily residential or RV use for 2-adults.

Millie & I lived with a composting toilet setup for quite a few years on a farm in Oregon and never had any problems with it…I bought a Sumar Composting Toilet to install along with a regular RV toilet for our Bus….
Here’s a pic of it inside our Bus

http://www.mobilehomestead.com/newbus/n ... ilets1.jpg

Because of size constraints (measly 27 feet interior ) we sold the composter.I only got rid of it because I felt it took up necessary room for other stuff I needed to install …not for any other reason.
Here’s a page of ours that shows the toilet in more detail

http://www.mobilehomestead.com/projects/compost1.htm

If I get to build our Trailer , I’m installing a Composting Chamber in the ‘Basement’ and we’ll use a Low-water Sealand RV/Boat toilet inside.
Right below the toilet will be a ‘Y” that has valves on each side that will allow us to either use the Composting Chamber or just Dump it into a Black Water tank (during cold winter months).
Here’s a link to what a Composting Chamber type of setup looks like

http://www.sun-mar.com/2002/Centrex2000NE.htm


I do have to say, I don’t suggest anyone should install a Composting Toilet in their Rigs…unless they first understand the principles of composting human waste products.
This isn’t ‘Rocket Science’ , but it does take some care & diligence in making sure you follow some simple steps.

1-NEVER put anything in the toilet that shouldn’t go there …IE. Old paint, Perfumes, Bleach, Women’s sanitary products, etc.
The only thing that goes into the Composting toilet is the ‘You Know What’, unscented (perfumed) toilet paper and compost starters & helpers (peat moss, sawdust etc.)

2- Try to keep the Composting Toilet and the area that it’s store in at 55-60 Fahrenheit.
Anything below 55 degrees slows down the Action…
It still works, but it takes longer to finish.
But when it gets to the freezing point …composting stops and goes dormant. This doesn’t hurt the Composting Toilet/Chamber , it just stops working until you bring it back up to above 55 degrees.

Here’s a link to Sunmar’s site where they show how a composting toilet works…and what you need to do to keep them working.

http://www.sun-mar.com/2002/how_compost ... _works.htm


Sunmars just one of many Composting Toilets available…I like them because they have a Long and very good record…plus they also make smaller models designed for RV’s and boats…which is nice for folks with small moveable homes.
But there’s other ways to go about this….

Here’s a link to a simple Low-Cost solution called a sawdust toilet …..basically it’s just a 5-gallon bucket w/toilet seat . You ‘use it” and cover stuff up with a bit of sawdust .
When the bucket is somewhat full , you dump it into an composting chamber or pile somewhere outside.
There’s No reason you couldn’t add a vent to the back of this type of system to use in a rig.

http://users.easystreet.com/ersson/sawdust.htm

This is Very Cool …The Folks who put out probably the Best book ever written on this subject ‘The Humanure Handbook ‘ have set up a website with lots of info from the book …
Here’s the link
http://www.weblife.org/humanure/default.html


Composting Toilets aren’t for everybody …I’m not advocating their use or anything here.
I just really like them because they allow you to stay in one spot for quite a long time…without worrying where you going to dump your Black Tanks contents.
For me that means if I’m parked somewhere out in the Boonies… that’s just one less thing I need to think about.

 

[gealto]

Yes, composting toilets can be the way to go!

Composting toilets are an excellent idea for a skoolie. I'm putting one in mine right now, almost as I post this message. Here in souther Arizona, where its very hot and dry, they work really well. If I lived farther north, where its cold and damp, I might think about the idea a little more.

Hey, here's an idea. Instead of spending about a grand for a space-aged marvel (the real main reason nobody uses them), build one for about $25 out of hardware store parts.

I'm using a 32 gallon galvanized steel trash can, with a tight fitting chip-board lid, and a vent pipe going out a side window. I use a small 12 volt muffin fan to pull air through the compost, which rests on a shelf made of hardware cloth about 6 inches from the bottom. I have drilled about 20 small holes in a circle about 5 inches high around the bottom, to allow air to enter in as it pushed out by the exhaust fan.

Before use, a layer of about 2 inches of peat moss is placed in the bottom. I do not let urine into the compost to simplify and reduce water load. Ordinary toilet paper is okay. Instead, I have a urinal mounted on the front of the inside. After each use, a cup of peat moss is thrown in the unit. Every few days, I remove the lid, and stir the compost with a stick of 1 inch PVC pipe, that I always leave inside.

I've used such a toilet in the past. With two people using it, it requires emptying anually, but no more than that. It's good to add a little water from the greywater, in order to make it work better sometimes.

These work on exactly the opposite principle of a normal toilet. Dry poop doesn't stink. Requires almost zero maintenance even with heavy usage. Costs even less than one of those stinky little camp toilets that take expensive deodorizer and special toilet paper.

 

[skyhorse]

My wife and I lived on our schoolbus in New Mexico for over 2 years using a simple, homemade composting toilet. We never had a bit of trouble with odors, flies or anything. It was simply a wooden frame over a 5-gallon plastic bucket. We put a layer of peat moss in after each use. When the bucket was full it would be emptied onto a compost pile. In a year we used the compost in our flower garden - it was great stuff. Next time we're living on the bus we'll use the same system.

 

[busone]

You all know more than me on the whole composting toilet subject so you will have to excuse my ignorance. I have a bad problem with my stomach and when I have to go I really have to go. It is very uncomfortable for me to run to the house from my shop everytime I get sick. How different is one of these composting toilets from one of the old outhouses? Would a 4' pit in the ground with a toilet seat over it and a fan to pull air through it work? Since the fan would be sucking air down through the seat could it be indoors is that a bad idea? I already built a urinal so moisture will not be of much concern. Do I have it all wrong here?

 

[skyhorse]

Can't help you with the other information you're looking for - all I can report on is the ease and success of my composting toilet experience. Didn't need fans or anything. There's routine work to empty the 5 gallon bucket and it is very important to cover the waste every time. Very simple.

 

[pete c-SKO]

I don't get these companies charging 1500 buck? wtf? it is basically a fiberglass tub with some sort of means to churn the crap. they also have a vent and a fan.

I hope to convert the rv toilet in my toyota motorhome to a composting one. I think that running a vent up through the roof with a muffin fan ought to do it. And from what I have read, urine actually helps the mix. I am also considering using a little free engine heat by running an engine coolant loop through it. Is this a good idea or will it provide too much heat?

 

[soused moose]

Pete a good composting toilet system is a lot more than just a fiberglass tub , there’s the outer shell ,the inner composting chamber and the finishing chamber….but I agree they are expensive in lots of ways.
One reason for the expense is they have to be built to a standard that would fulfill building codes.

And yes you could covert your RV toilet over to a composting one….but you’ll have to cut down the water supply going to the toilet. Most standard RV toilets use more water to flush then you want to use in a composting system. Sealand low-flow toilets work well with composting systems, most other not so good.
Are you thinking of building a ‘Box’ with a composting drum under the toilet?
Or going with a separate Composter under the bus?
Like this sort of thing….

Urine does help composting a bit ,but too much liquid in the system turns things into a mushy mess …that’s why Composting toilets always have a drain to run off the excess …so you want to do this with your system.
I suggest plumbing a drain to your existing Black water tank for this.

Yes , heat is important to composting. But you want to be careful to not apply too much heat because you just dry stuff out. In composting you want just enough heat to keep the composting action doing its thing.
Composting produces it own heat ..so you’re always trying to keep a minimum of 55 degrees Fahrenheit in your toilet which allows the microbes to do their job….but above 90 degrees the microbial action gets a bit sluggish and the composting action slows down.