Composting Toilet — Report on 8 months full time usage

[FellowTraveler]

Adding heat for better composting

I've considered making my own composting toilet for my rig and considering adding heat to the mix via a heat exchanger using engines cooling system.

My theory is while underway the temp would rise in the compost system but not to the level of the engine temp because of venting, thinking venting can be reduced a little to raise temps.

 

[dwh]

I've considered making my own composting toilet for my rig and considering adding heat to the mix via a heat exchanger using engines cooling system.

My theory is while underway the temp would rise in the compost system but not to the level of the engine temp because of venting, thinking venting can be reduced a little to raise temps.

One problem is that the beneficial bacteria die at around the same temps as the pathogens. So if you raise the temp of the compost from warm to hot, then you don't end up with compost, you end up with cooked sewage.

Might be sterile though.

Composting takes time for the bacteria to do its work. When it gets too cold, the bacteria goes dormant - too hot and it dies.

How long do you expect the heap to remain in the vehicle for that process to happen? 6 months would be a good start.

 

[FellowTraveler]

One problem is that the beneficial bacteria die at around the same temps as the pathogens. So if you raise the temp of the compost from warm to hot, then you don't end up with compost, you end up with cooked sewage.

Might be sterile though.

Composting takes time for the bacteria to do its work. When it gets too cold, the bacteria goes dormant - too hot and it dies.

How long do you expect the heap to remain in the vehicle for that process to happen? 6 months would be a good start.

Oh well back to the drawing board!

 

[DzlToy]

...diapers [are] allowed in landfills... plus sewage sludge from wastewater treatment plants was routinely dumped in landfills.
Given that phone call, it's hard for me to imagine that dumping the output of a composting toilet into a landfill would be a problem.

^^This

additionally, have you even done number 2 in the woods? do animals do both in the woods? do guys routinely pee off the side of a trail when camping, hiking, mountain biking, rock crawling, dirt biking, etc?

Im not saying pollute the environment by any means, but lets use some (un)common sense here..

The OP just shared eight months of his personal experience using a composting toilet. I would guess that he has encountered just about every possible thing one could encounter during that time. If you want a flush toilet and blackwater tank or incinerator toilet, get one, but based on this post and many others like it, there are many advantages to composting toilets.

 

[dwh]

but based on this post and many others like it, there are many advantages to composting toilets.

No doubt. But making compost isn't one of them, since they don't actually do that.

 

[r_w]

No doubt. But making compost isn't one of them, since they don't actually do that.

Yes they do, eventually; just not in the timeframe we are talking about...

I wish I would have known about this toilet, as the one I bought for my cabin was way more expensive and way harder to deal with. I am going to buy one of these for my workshop, as I don't have to punch the metal roof for the vent.

 

[kerry]

Kind of off topic, but the comparison between a typical RV toilet and a composting toilet is not the best comparison. There are RV toilets which re-circulate the liquids in the flushing process so can store much more waste by volume than is typically found in an XX gallon black water tank. Electro-Magic is the name of the one with an electric pump but Thetford used to make one with a manual pump. I had an Electro-Magic in a Travco motorhome I owned and really liked it. You charged it up with a couple of gallons of clean water and it re-circulated it until the toilet was full of waste and was then dumped into the black water tank.

Here's a manually operated re-circulating toilet desgined for locomotives. Anyone have any experience with one?

http://www.dayton-phoenix.com/productCategoryDetail.php?categoryId=76

 

[grizzlyj]

We have a 70 litre black tank, and around the UK, France, Spain and Morocco its mostly a pain. Even with bagging the paper, and bottling the pee, its full in about a week. We do have a container that it can be decanted into, but thats not fun. Once the outlet valve froze which I eventually freed with a tent peg, smashing! Many campsites cassette facilities are too far uphill from the camper, so more 4" pipe is not the answer

A macerator may be better, but since most facilities are either a toilet or somewhere designed for a cassette to be tipped (so 20-25l then flushed) that may be more complication and little gain.

A cassette is what pretty much everyone uses, but needs emptying more often of course.

So a composting toilet is definitely under consideration, and thank you for this thread. The fact that it hasn't finished composting is a moot point. You end up with a smaller problem to deal with which has to be a good thing.

Except;

How much volume is there when its full?

If a toilet, perhaps in a filling station, was the only option at the time, is it flushable?

Do the two seperate containers have sealed lids? If not what happens on a washboard type surface?!

Does it need "special" moss, or anything at all if you only partially emptied it to keep some bugs in there for instance? So is it suitable for a round the world trip without taking a trailer to carry supplies!?

As much user info as you think is polite would be cool

Cheers

 

[FellowTraveler]

I'm still thinking about composting!

We have a 70 litre black tank, and around the UK, France, Spain and Morocco its mostly a pain. Even with bagging the paper, and bottling the pee, its full in about a week. We do have a container that it can be decanted into, but thats not fun. Once the outlet valve froze which I eventually freed with a tent peg, smashing! Many campsites cassette facilities are too far uphill from the camper, so more 4" pipe is not the answer

A macerator may be better, but since most facilities are either a toilet or somewhere designed for a cassette to be tipped (so 20-25l then flushed) that may be more complication and little gain.

A cassette is what pretty much everyone uses, but needs emptying more often of course.

So a composting toilet is definitely under consideration, and thank you for this thread. The fact that it hasn't finished composting is a moot point. You end up with a smaller problem to deal with which has to be a good thing.

Except;

How much volume is there when its full?

If a toilet, perhaps in a filling station, was the only option at the time, is it flushable?

Do the two seperate containers have sealed lids? If not what happens on a washboard type surface?!

Does it need "special" moss, or anything at all if you only partially emptied it to keep some bugs in there for instance? So is it suitable for a round the world trip without taking a trailer to carry supplies!?

As much user info as you think is polite would be cool

Cheers

Your points are interesting indeed, and more user input is a great idea!

 

[JRhetts]

..

How much volume is there when its full?

If a toilet, perhaps in a filling station, was the only option at the time, is it flushable?

Do the two seperate containers have sealed lids? If not what happens on a washboard type surface?!

Does it need "special" moss, or anything at all if you only partially emptied it to keep some bugs in there for instance? So is it suitable for a round the world trip without taking a trailer to carry supplies!?

Volume: Pee bottle is ~2 gal.
Solids =~ 2.5—3 gal in volume when full; fits easily in a standard
trash (under sink) liner bag; the solids mix and begin
'melding' with the peat moss, so the final volume of
solids seems virtually equal to the initial charge of peat
moss

Flushable: the pee certainly is; the solids are NOT

Sealed Lids: the pee bottle has a sealed cap when carried out for disposal; when riding along neither technically has a sealed top; the pee is gasketed to the underside of the toilet bowl and the solids have a closed flapper lid and seat cover. We have rock and rolled over VERY rough terrain— far in excess of washboard roads — with pretty full levels of both, and have NEVER had a spill. The solids simply do not flow, and the pee does not splash out through the bottle's entrance in our experience.

Special Moss: the solids are charged each time after emptying with ordinary peat moss (obtainable virtually everywhere in the world as far as I can tell); when one empties you inevitably leave some residue which contributes to jump-starting the new batch; we generally carry a 6-month supply in 6 x 2.5 gal zipperlock bags in a back locker - not very much room at all [perhaps 2-3*cuft] — certainly not a 'trailer's' worth!!

 

[kerry]

Comprehensive review of the Air Head composting toilet in the September/October issue of Good Old Boat. Users are happy with it installed in a 34' sailaboat.

 

[Dirtytires]

sounds look a bunch of **** to me. Good write up.

 

[kleaver641]

I guess its time for a report on our use of the NaturesHead composting toilet.

As a part of our remodel of our Darrin Fink-built FusoFM260-based expedition vehicle, we elected to install a composting toilet in lieu of the Thetford cassette. We have been living in the rig full-time for 8 months.

We primarily wanted

• longer between-dump times,
• less water usage, and
• more flexibility in dump strategies,
• without incurring any increased 'messiness' in the process.

OVERALL EVALUATION: BINGO!!! This has been a winner!

The unit is very well made, simple to install, and the company provides excellent customer service.

As a baseline with the Thetford cassette, two of us living aboard full-time had to dump every other day. And despite the fact that we both preferred to dump a cassette rather than deal with a hose and a big blackwater tank, with a cassette it is still a smelly and at least mildly messy business.

NOTE: With this kind of composting toilet the physical apparatus separates urine and feces. So you have two separate vessels to empty. While this may sound like more work, we DEFINITELY found IT IS NOT. The nasty smell comes from combining the two; neither alone is particularly bad [ esp. not the feces.]

With the composting unit, in warm weather we got up to one month between dumpings of solids, and in cold weather [averaging low 40s to low 20s °F] it averaged 10-14 days between dumps of solids. The liquid bottle had to be dumped regularly every other day, but this was MUCH easier than the same frequency with the cassette combined output. Simply put, we could dump sterile pee lots more places with less splashing and odor than the combined output from the cassette. The solids are remarkably easily dumped into an ordinary plastic 13 gal garbage bag, and then either spread around as fertilizer or placed for landfill collection. And since the solids are not in liquid form, there is NO SPLASHING or other objectionable side-effects from doing the dumping.

Interior smell from the toilet was virtually non-existent until we had reached the limit of the peat moss volume, and then it was more like a gentle nudge to "do the job."

We used a small spray bottle with water to "assist" the last of one's pee to fully vacate the front part of the bowl, so water usage was less than one liter per dump — i.e., VERY low.

We find this an optimal way to deal with the inevitable problem, and are very glad we went this direction.

SO, after 8 months of full-time 'living', these are our observations.

John

very nice post! indeed detailed information! good job!

thumbs up!

regards,

kurt

 

[dzzz]

A macerator may be better, but since most facilities are either a toilet or somewhere designed for a cassette to be tipped (so 20-25l then flushed) that may be more complication and little gain.
A cassette is what pretty much everyone uses, but needs emptying more often of course.

One issue in the U.S. is that no waste stations are designed for cassette. This is O.K. except when the pipe is in a shallow bowl below grade. Unfortunently it takes practice to dump a cassette successfully in this scenario
I have 100+ nights now using a cassette. I do like it better than a tank system (for how I travel). I think for two or more persons it would be on the small side. I would seriously consider a composting toilet for two people multi week travel.
But of course it depends on many factors.
For overnights (say a state park) I hook up nothing even if connections are available, which is nice. I find the whole RV hookup thing an annoyance. That gives a big plus to the composting toilet IMO. Waste needs to be managed in all scenarios. I would only consider a black tank if traveling with kids.

 

[DiploStrat]

Another Contender

C-Head: http://c-head.com/index.html Smaller, less expensive, less capacity, but some interesting ideas. Like the use of common containers. (I didn't want to say disposable.)

Some churn on this subject on a sailing forum: http://www.sailnet.com/forums/gear-maintenance/58601-composting-toilet-report.html

Like a lot of subjects, there are a lot of phanbois and an equal number who insist that it simply cannot work. :Wow1: