Composting Toilet

[Just Dallas]

Removed

[Old Scool Bus]

So I guess the bottom line is I will have to find another source of information as to the makeup or how to build the mechanical part of a "Composting" not incinerating or any other type of toilet.

[Old Scool Bus]

Pooping in a bucket doesn't mean you have first hand knowledge how to build or how a commercial unit works. I've Googled this for months.

Your replies were exactly what I expected from you. Before I go away think I'll try the ignore option to see if that works.

[Just Dallas]

Removed

[Sean]

Folks,

Let's not confuse composting toilets with incinerating toilets.  These are two very different animals.

The OP asked about composting toilets, which do exist, even for mobile applications.  I've seen them for as little as $1,500, half what the OP suggested (http://www.google.com/products?q=composting+toilet).  Some of the replies here have concerned composting, and some have concerned incinerating toilets; the photo Paul posted is of the latter type.

Incinerating toilets are anything but green.  They use a huge amount of power, and turn what started out as relatively environmentally friendly human waste into airborne pollution.  Their principal advantage is that they require very infrequent cleanout and no sewer connection, making them ideal for such applications as railroad locomotives, which frequently operate far away from sewage disposal facilities, but have essentially unlimited electric power available.

A composting toilet, by contrast, uses minimal power, just enough to operate the "flush" mechanism, a circulating and/or vent fan, and a small heater to keep the compost warm in extremely cold conditions.  They process waste in the same way the earth would naturally, just on an accelerated schedule.  These are ideal for remote locations where a septic system is impractical due either to logistics of transporting the components to the site (septic tanks, relatively speaking, are quite large), inaccessibility of the site to pump-out equipment, or unsuitability of the site for septic leach fields.

You can certainly use a composting toilet in an RV, but since an RV can easily travel to proper sanitary dump facilities, it is an expensive way to go.  But a larger concern is that human waste is only a small fraction of wastewater generated on board an RV.  Depending on the type of toilet an RV has on board, human waste and the water used to flush it constitutes anywhere from one half down to one tenth of the total waste generated.

Since discharging gray water other than in a sanitary sewer is illegal in most places, and discourteous in others, there is little practical value to a composting toilet in an RV -- you'll still need to find a dump station periodically, and there is little additional cost to adding another 10%-50% tank capacity to accommodate the human waste.  Composting human waste is not really any "greener" than conventional sewage treatment methods, and, depending on what's done with the resulting compost, one can even argue that composting is quite a bit more dangerous.

To answer the OP's question, the "composting" part of a modern, compact composting toilet is more or less the whole thing, and accounts for most of the cost.  They are actually quite complex.  If $1,500 is too steep, your only option would be to construct the whole thing yourself (or perhaps find a, ahem, used one that needs repair).  It's not hard to do, and plans for various methods abound on the Internet.  However, expect the result for a home-built system to be significantly larger than a factory-built compact model.  I would expect that, overall, the waste system would take up more room than a decent-sized black tank would.

-Sean
http://OurOdyssey.BlogSpot.com

[Van]

I am still very much curious (besides being green)as to the motive of all of this. Sean, right on good points you brought up,OSB is there some advantage this method, please share your thoughts ,thanks

      Van

[John316]

Old, you asked a question, so let's please keep this nice. If you want to keep your info, that Dallas requests, fine. But then you shouldn't have asked in the first place.

Yes you are a noobie. I don't mean to pile on you, but since you are a noobie, we don't know about you. We (others) have to ask questions to get to the bottom of what you want.

I can't understand what you have going on, here. Why don't you just answer the questions, be polite, and an adult about the process....

We like you on here, fella, if you are polite. Remember, asking a question is a two way street. If you ask a question, expect others to ask questions, and then you should give a little info. But don't get all huffy about it, please...

God bless,

John

[thejumpsuitman]

I'm sorry, but I could not even remotely imagine someone going through all this "crap" to create a composting system unless that's the only option available.  Is it just me?  I am just shaking my head over all this.

Marc

Well let's take your stance on this a little farther.

Why would anybody take an old beat up worn out bus that has outlived it's usefullness to it original purpose and throw thousands of dollars and thousands of hours of human labor not to mention the stress and ridicule from others to do what we do when prevost are readily available turnkey?

It's not about cost, readily availableness, or time spent it's about accomplishing something that creates a satisfaction within us.

Calling someone Else's ideas, dreams or projects stupid or even insinuating such us rude and very short sighted or for a lack of a better term "Stupid"

To each his own  Here in America we have the right to waste our time and money however we see fit.

Marc

[philiptompkjns]

Not at all.
All you have to do is be forthcoming with some information.
Here: I'll start:
You aren't going to find, beg, borrow, build or use a 'fast composting' toilet without using electricity and/or another heat source.
Most of the composting type that I've dealt with are complicated and finicky, they also draw in the area of 150 to 500 watts of electricity for hours at a time.. Usually about 60 watts for the fans alone. BTB, DC fans like used on the DC systems don't work that well and eat a lot more power than their AC counterparts.
The motors that turn the turds are another draw that is better left to an AC motor. DC motors have a tendency to burn out.
The longer the heat is held at the optimum temperature for composting, the faster it will work... there is the bottle neck. If the heat goes to high, you kill the bacteria, if it's to low, they become dormant.
A 200W solar panel will NOT run a composting toilet for the required time to perform it's function.

How many times per day will your unit be used? How much liquid will you be putting into it? How large is the compost usable area?
Want to talk about incinerating toilets? That is a whole different ballgame.

Now, what other information do you want?

Ignore away.. it works two ways and I do believe you may be the south bound end of a north bound mule.

So I guess the bottom line is I will have to find another source of information as to the makeup or how to build the mechanical part of a "Composting" not incinerating or any other type of toilet.

Maybe I'm demented but the  thought of burning the  Sh1T out of my bus makes me laugh.

[Old Scool Bus]

The purpose of this is it can hold up to a years worth of crap without being dumped in a container that is half the size of a black tank. At least manufacturers claim this. They are supposedly odor free and after the composting process the peat moss like substance is environmentally safe.

There are several types and methods to accomplish this. Passive or active, manual or automatic, water or waterless, remote storage or self contained.

The self contained units have finishing drawers that hold the very fine humus and need emptied accordingly, they also sit very high. cost are about $1,500.00 +

The models that go in your basement are much more expensive but you get the appearance of a normal toilet.

Now asking me about the power source is in no way needed or helpful and was later confirmed there was very little if any real knowledge about building one. It does not take an absorbent amount of any energy to operate one of these and I have that part covered. And very efficiently.

I want to build a box that fits well in my bay, outfit it with a SS drum out of a compact washer, poop down the shoot into it, add some sawdust or coffee grounds to cover smell and help with composting, crank the drum weekly or as needed and let dried finished compost filter through hole as well as any moisture that doesn't evaporate.

That is the basic idea but there is much more to it.

I have already built a waterless urinal or at least have it half done so the toilet will not get too much fluids.

I have googled for months trying to find actual plans with no success I was hping someone actually knew how they are built, but it appears not.

 

[John316]

Old,

Now you are getting the drift . That was a good post. Good for you.

God bless,

John

The purpose of this is it can hold up to a years worth of crap without being dumped in a container that is half the size of a black tank. At least manufacturers claim this. They are supposedly odor free and after the composting process the peat moss like substance is environmentally safe.

There are several types and methods to accomplish this. Passive or active, manual or automatic, water or waterless, remote storage or self contained.

The self contained units have finishing drawers that hold the very fine humus and need emptied accordingly, they also sit very high. cost are about $1,500.00 +

The models that go in your basement are much more expensive but you get the appearance of a normal toilet.

Now asking me about the power source is in no way needed or helpful and was later confirmed there was very little if any real knowledge about building one. It does not take an absorbent amount of any energy to operate one of these and I have that part covered. And very efficiently.

I want to build a box that fits well in my bay, outfit it with a SS drum out of a compact washer, poop down the shoot into it, add some sawdust or coffee grounds to cover smell and help with composting, crank the drum weekly or as needed and let dried finished compost filter through hole as well as any moisture that doesn't evaporate.

That is the basic idea but there is much more to it.

I have already built a waterless urinal or at least have it half done so the toilet will not get too much fluids.

I have googled for months trying to find actual plans with no success I was hping someone actually knew how they are built, but it appears not.

 

[Busted Knuckle]

Well so far along I have tried to avoid this one as I know nothing about S**T!
But I have watched this progress and have to say, that I
1) Still don't know S**T about CRAP!
2) I believe everybody got a little testy on it for a little while, but it looks like in the end everybody has calmed down and discussing this S**T about CRAP more civilly! And I'm glad because I was wondering if I was going to have to ask the monitors to kick this CRAP off, because we all know we don't want a S***TY board!

OK now go back to discussing whatever CRAP, trips yer trigger!
  BK 

[Van]

Thanks Old School Bus, very interesting concept indeed,thanks again Don't worry about these guys,they mean well and all have a heart of gold,iron sharpens iron and all that ,and it's a good thing.Welcome to the board and keep on posting.

  Remember, "The Greatest Pleasure in life(besides a good crapper;D LOL) Is Doing The Things People Say You Cannot Do, And Doing It With The Ones You Love Good Luck.

    Van  

[bobsw]

I would still like to know how much power it takes and what your source will be so we all can better understand the over all project.

[Sean]

The purpose of this is it can hold up to a years worth of crap without being dumped in a container that is half the size of a black tank.

Well, OK, but you still can't store a year's worth of gray water, so you'll still be searching for sanitary sewers every couple of weeks, maybe a month at best.  So I'm having trouble understanding the putative benefit of this system, considering it will take more energy (to run heaters and fans, even if the drum is hand-cranked) than a conventional RV toilet and conventional sewage processing.

I want to build a box that fits well in my bay, outfit it with a SS drum out of a compact washer, ...

OK, so this is very different than a compact composting toilet, which is what I understood you to be asking about in your OP.

If I have this pictured correctly, assuming you build a rectilinear (rather than curved) box, to fit a washer drum, plus the required drop for the material, plus the bearings and cranking mechanism, I would guess you to be looking at perhaps two feet on a side, give or take.  That's eight cubic feet, or about 60 US gallons.

60 gallons is an enormous black tank; with a direct drop toilet, which typically uses less than a pint of water each flush, that's a couple hundred flushes.  The average human produces 1-2 liters of fecal matter each day, so a tank this size could go close to a month with two people who used it full time (meaning they never defecated anywhere else, such as at work, campground restroom, etc.).  Again, you will need to be finding a place to dispose of your gray water by then anyway.

Call me dense, but this makes little sense to me.  You are proposing to add lots of complexity and expense for no real gain, IMO.  I suppose if your plan is to park, without moving, for months at a time, and you intend to send your gray water to a direct leach system (i.e. without a septic tank), then this might be of some use.  But be advised that that practice is illegal almost everywhere, and inadvisable in most cases in any event.

That said, as I wrote earlier, plans for DIY composting toilets (and systems) abound on the Internet.  But I would recommend you post your request for direct experience on the forums that are dedicated to human waste composting, rather than RV forums, since the vast majority of RV (including bus conversion) owners would have little use for such a system.

As I also wrote earlier, commercial systems are complex, and were developed and perfected through hundreds, if not thousands, of hours of testing.  I would caution you against thinking you can just find a used washing machine drum and make this work on the first try.  Every aspect of these systems, from the size and aspect ratio of the drum, to the size and shape of the perforations, to the exact temperature of the chamber, are studied and tested to ensure an optimal balance.  Even then, the systems are finicky -- and that's in a fixed location, where temperature and humidity have less variability than in an RV.

Note also that it is easy to underestimate the power requirement, which you claim to have "well covered" (is that a pun?).  You can build a composting toilet system that uses no power at all, but it's throughput will be very low (per unit volume).  If you really want it to support a couple of people full-time, be compact, and only need to be emptied every six months, you will need to provide lots more heat and oxygen, and that takes power -- commercial systems use around 4kWh per day.  My entire coach uses less power than that most days.  To put that in perspective, if you were to run such a system on solar power, you'd need about eighty square feet of solar panels, properly tilted, in a place where the sun shines every day.  Add to that number for cloudy days, incorrect alignment, etc., and pretty soon you'll have the whole roof covered just to run the toilet.

I would suggest you build a full-scale prototype of your system and test it thoroughly over as much as a year before designing something into your bus.  You might find that it is not as simple as it might appear on the surface.  Just my free advice, possibly worth what you paid for it.

-Sean
http://OurOdyssey.BlogSpot.com