composting toilets - AC or DC or NE?

bobdog · September 2009

I am planning on using a composting toilet at the cabin. My system is currently 550AH of Batteries, 2 KC-130s, and a 750 watt MSW inverter. My question is whether or not my system is sufficient to run either the AC or DC "hybrid" set-ups listed below?

On one brand the heating element is a thermostatically controlled 260 watt AC heater. The fan in AC mode is 35 watts. It also has a DC mode with a 1.4 amp fan. Would possibly add a second fan.

On the second brand the heater is 540w and the fan 40w in AC mode. DC mode is (2) 1.0 amp fans.

I will run AC and DC to the bathroom so have a choice either way. The benefit of the AC is the heater eveporates the excess water. Without it, I am somewhat concerned about it not working properly when it gets below freezing.

So, any suggestions or advice would be helpful.

Thanks.

Cariboocoot · September 2009

Re: composting toilets - AC or DC or NE?

Running a fan is no problem: it's those heaters that will get you. And you can't predict how much it will be on.

I remember looking into these a few years back and it seems to me there was a model that burned propane instead. See what you can find on that.

Just switched from outhouse (zero power) to septic system. Expensive to put in and it requires a 1 HP pump to run about 1.5 mins per day. And of course you have to have enough space for the tank and field.

BB. · September 2009

Re: composting toilets - AC or DC or NE?

Composting toilets really eat up the electric power

Try finding non-powered versions (may still have a small vent stack fan which can be off-grid powered but still needs a liquid drain of some sort)...

Here is an interesting little post. Issues with flies and even problems with water condensing in vent stack and going back in toilet (urban home trying to go "green").

Or, the classic outhouse pit?

-Bill

dwh · September 2009

Re: composting toilets - AC or DC or NE?

From what I understand, the main reason for a heater in a composting toilet is to evaporate the water (urine). For this reason, composting toilets which separate the liquids from the solids don't require a heater - just a vent fan.

Here is one such (originally designed for marine use):

http://www.natureshead.net/

For cabin use, it still leaves the problem of what to do with the urine. I have a friend who has one of those "99 year" leases on a beachfront lot in Baja California. He's got a porta-potty, but since Baja Beachfront R&R is largely about beer...that porta-potty would be constantly full if you used it for urine.

What he did was construct a screened urinal on the side of his little cabana shack. He dug a hole, dropped in 3 50 gallon plastic drums with about a million 1" holes drilled in them. He then filled the drums with gravel, put the tops back on them and filled in all around them with sand. He made a plywood cover with a hole in it for the drain from the urinal.

[EDIT: Just noticed I left out some detail...

The three drums formed a tight triangle. The center of which was also filled with gravel. The drain from the urinal comes in at the center and drains down into the center - not into one of the drums.]

That rig has been there for years. There have been some *serious* beer bashes there but "the pit" has never overflowed or to my knowledge experienced or caused any sort of problems.

You could combine the two by installing a liquid separating composting toilet, and draining the liquid reservoir part into a small septic system such as my friend built in Baja.

Mountain Don · September 2009

Re: composting toilets - AC or DC or NE?

One thing to keep in mind is that composting stops at about 50 - 55 degrees F. At out mountain cabin nothing composts from fall through to spring. We have the Sun-Mar. It does not separate the urine like some, but we've never had a problem with the urine. There is an overflow tube just in case. The heater does help with evaporating any excess liquid. We our use frequency drops there is usually a problem of not enough liquid.

I have the AC/DC unit. I have things wired up so when the generator runs I can opt to run the heater if desired. The heater will not run off the inverter and drag the batteries down. It is also possible to disconnect the AC heater and only have the AC an run off the inverter. I rewired things and can run the AC fan off the inverter if I choose to.

Note that if the 12 VDC fan is installed in the 4 inch duct it will block the free convection circulation. I used the 12 VDC fan for a while and then removed it from the vent stack. With a 14 foot vent stack length there is very good natural circulation.

I did have to install a fresh air inlet or the wood stove though as at times the wood burner would cause a back/down draft through the Sun_Mar vent. Smelly! Opening a window also helped but in the middle of winter I try not to do that.

mike95490 · September 2009

Re: composting toilets - AC or DC or NE?

I'm looking at the same delimma. My vote was for the non-electric, $15 luggable Loo. That's the 5gallon bucket with a seat. Another bucket for sawdust. Pee at a tree.

For $1K for a compost toilet, I've not found anyone happy with them. I've got survey I did about them - even had several offers to sell me a used one.

icarus · September 2009

Re: composting toilets - AC or DC or NE?

I have a s#*tpot of experience with composting toilets of many brands. The reality is that they ABSOLUTELY need heat to work in any but a very warm climate. They need heat to reduce the amount of moisture AND to keep the "compost" at a temp where biologic action will work. Off grid, I built several units that used small propane burners to put heat in and they worked quite well. They burned ~40# of propane per month. I just didn't feel that it was cost effective. The 120 vac units burn ~500 watts, and need that heat for at least 12 hours a day, pretty tough to do off grid. (Even on grid I would shy away, personally).

I don't have the energy tonight to write all about my experiences, but if you wish I will do so later.

If it were me, I would forget the idea of a composting toilet if you are off grid, and opt for a well designed, well built outhouse instead. Much cheaper, no smell, very safe for the environment (if built properly) and you never have to handle any thing that resembles ,,, well you know.

Tony

Photowhit · September 2009

Re: composting toilets - AC or DC or NE?

Lots of Code issues here,

A septic system shouldn't require any electric unless your code requires an airator. (or you have to pump uphill, most are gravity fed)

Out Houses in the states are outlawed in many states, even here in Missouri. In other states they require a sizable land holding, Arkansaw was 10 acres when I was looking to build a cabin in the 90's.

Even French drains for grey water are outlawed in most states, they are recently outlawed in Missouri.

I had a choice between a holding tank or a composting toilet. I had experience with a SunMar in Florida, warm humid climate and found them OK, some earthy smell and issues with keeping things dry, household with 1 pee on tree and 2 women...

I had a friend here building a Barge/boat who had a biolete in a camper while he was building and transfered it to the boat later. He had an electric that he was using on fan only with out a problem during the summer, No smell no water problems, it has a drain/over flow but he used the pee on a tree method of control. I haven't heard how it went on the boat.

One of the issues with a composting toilet is that they need to "finish composting" some have 2 collection bins, while the biolete and others require a rest of 6-10 weeks of use to finish or to deposit waste into an existing compost bin.

As to Code and the composting toilet, There are only a couple that have NSF certification SunMar has a couple, I don't think Biolete has.

So I have a Biolete, I don't have a compost that is secure of animals, but I have a bathhouse where I work so plan to allow it to finish in the toilet next spring (you'll be surprised how little your waste reduces too.)

While in use the biolet heater is thermostaticly controlled they claim between the controled heater and 25 watt fan it will average 50 watts an hour, I put in 3 watt fan and it doesn't draw back into the room with the door opening if I put the cap on, with just the lid down I have to not jerk the door open. I have no proble with moisture(yet) but I'm a guy... The base has been 75 or above until this week, I've read that you can insulate a bit and put a timer on the heater to only run during the day and they will hold temp with the composting action. Though thats just smoke at this point.

Well this post started 3 hours ago, I've rambled all over hope it makes sense. I'm at work...

icarus · September 2009

Re: composting toilets - AC or DC or NE?

Out houses are outlawed more for political rather than environmental reasons. They are symbols of "poor" or "backward" so that county and state governments concerned about their image ban them, even at the expense of the environment.

A huge issue with septics is taking 1 qt of black water and adding potentially tens of gallons of clean or grey water to it, turning that 1 qt into tens of gallons of black that the septic has to deal with. Most septics that fail do so without anyone being aware that polluted water is being introduced to either the surface water or shallow subsurface water.

An out house on the other hand, take that same ~1 qt, and adds no additional water, and nature does it's thing. Assuming a deep enough static water table, there really is no safer way to dispose of human waste imho.

T

stephendv · September 2009

Re: composting toilets - AC or DC or NE?

An interesting design I came across is the Separrett: http://www.separett.eu/ It separates liquids from solids, the solids go into a bucket which you periodically empty. You could think of it as swedish style meets cr4p in a bucket

mike95490 · September 2009

Re: composting toilets - AC or DC or NE?

A month or so ago, I pinged the Mendo Community maillist about their experiences with "Composting Toilets". It was completely unscientific and could be way off base. Mendocino residents have a fairly independent attitude, and I hope I got usable responses.

What I arrived at, was that the Loveable Loo style, seems to be as useful as any of the other mega-priced gadgets. Do you turn a crank, and work some levers and hope the $$ innards stay intact, or carry a bucket outside between rainstorms

DIY
http://www.jenkinspublishing.com/sawdustoilet.html (about $30)
Store bought: ($200, nice wood construction) http://josephjenkins.com/store/product.php?productid=16161&cat=283&page=1

Determination's:
1) ALL low-power composting toilets have problems with liquids, and require a urine drain or tank or a tank that must be emptied somewhere.

2) All require carbonaceous material to be added (sawdust, peatmoss or "magic mix powder $")

And now the details:

Q. Anyone off grid with composting toilets, that have a real winner, or are they all losers? I'm wondering if any are worth the $1,700 price tag, or is a "throne & bucket of peat moss" the better way to go?.
Thanks

a)
I have had an very expensive sunmar and it was the worst "investment" ever made.
I have 5 other friends with SunMars that are very unhappy with them, for smell and inability to compost.
You basically wind up scooping raw poop out.
We now do the 5 gallon bucket Humanure thing and we love it.
We're making lots of compost for the orchard and our toilet cost less than $20 to build.
Good luck to you!

b)
Mike, been using a mid line sun-mar for 4 years and have nothing but good things to say about it. I think it went for ~$1100 and it has paid for itself in water, power and personal responsibility enhancement. Needs a light dimmer to cut down the noise and power consumption and could use a little higher seat - which is a standard mounting item. I would go to the larger unit if more people or money allowed.

c)
I have an envirolet composting toilet. It is low water flush. If I had known what I know now I would have bought a toilet and done the composting part myself with a 50 gal drum and small gravel leach area. Save the money and do it yourself.... speaking from experience. let me know if you have any questions...

d)
We have a rotating drum composting toilet. It is a real pain in the xxx
to clean out. And the stuff isn't really composted no matter how much
moldy bread, peat moss or green stuff you add. If I had it to do over, I
would get a hospital-type potty chair, put a bucket under it, and use
peat moss, saw dust or kitty litter. Then, if using peat moss or saw
dust, dump it out in a safe place to compost for a few years. Use to
dress ornamental plantings. If using kitty litter, line your bucket
with a plastic bag first, then throw the thing in the garbage when it's
full.

e)
I never had one myself, but a couple of folks I know got the factory units, and it seems like a lot of money for little real advantage. The compost method works fine with proper attention. I have one that's been going strong for almost 30 years - pretty much just a standard outhouse built on top of a concrete double-bin. The bucket & peat moss thing is effective, but requires a little more fussing. You can do it.

f)
if you are interested I have a new one that you might buy for $840... I hardly ever need it, so when using the cabin, we just take the shovel... my property is steep, so hurling it down the hill, seems to be good enough, every now & again.
re composting toilets, I'd have it outside in a separate little closet type room, only use for # 2 and use Kombutcha & baking yeast w the peat moss. Burn the paper in a coffee can, after each use, and the small room takes on the odor of the burnt paper, highly preferable smell.

g)
ok so heres my feedback
after the bucket & ashes/sawdust mess in the 70’s, my 3 grown boys still talk about the out house days to friends, its like a badge of accomplishment, I moved up the hill to a real house w/ a sunmar, non electric throne. it had the drum that got turned & emptied into a drawer which we dumped in a compost bin w/ 2 compartments. we would fill one side & then let it sit for 6 months to break down while we used the other side, back & forth. the aged compost we spread out over flowers & trees & forest land. (did the same when we emptied bucket in the ‘old days’. ) there was just 2 of us using the sun mar throne, & the tp got burned, & we had a separate pee pot. (a bar sink w/ toilet seat, w/ spray wand for ‘flushing’.) the boys, my kids & male grandkids I asked to pee outside when they visited. I did find that peat moss is a much better mix for covering poop. .unless its aged sawdust the breaking down of it depletes the nitrogen & it hangs out
instead of breaking down. peat moss also better for smell & finished product. so the throne lasted for 22 years, 2 breakdowns & more fruit flies than I ever want to see again. I used diatomaceous earth & lime to control fruit flies in cold weather. the throne did not have a heat unit (off grid) or fan to keep condensation down. it was also in a almost detached small room w/ out heat cept what came fm water heater that shared the room w/ a little sink. also when the it got too wet w/ too much use it did get fruit fly problems. the last breakdown came when I could not handle another yr of ff & I wanted to rent a room in the house so I had lots of incentive to upgrade. It needed a new gear thing to turn the drum. so I let it dry out, emptied it & moved it outside w/ the intention of using it at the barn when it gets fixed. new part no problem fm company. used a bucket till I invested in the sun mar centrex 2000 ac/dc. I did a lot of investigating & asking
around. the main thing was to get a low flush toilet inside & the compost unit outside. it has some draw backs, some points I can & will fix to make it possible to maintain it. 1) I don’t have the dc fan in flue to facilitate the drying out of condensation, pee, water. 2) it is too flat so it does not drain in a timely manner so the compost stays too wet for breaking down rapidly. 3) I was limited to where I could put it so it is not real easy to turn the drum or empty. since I have since moved to an other little house on my land w/ a regular septic system (all to code, 1st time since I bought this forest in 73.) & rented it to a person who did not want to do the drum turning or let me know when all was not well…it has suffered. the renter is gone & I wont rent it again till I get the fan in, the drum set right & a willing renter. but it is so nice to have the regular toilet when my family comes to visit. I don’t mind fooling w/ it cus its an
upgrade for me. I also don’t use peat moss anymore cuz it not p.c. coconut fiber is the new thing, it works great, is cheep, & smells nice. I would encourage the inside flush & outside drum depending on your willingness to maintain & do all that is called for. my finished compost from drum still goes into the same compost 2 sided bins outside. oh, the only time it has the electric fan going is when I have the genny on to charge my batteries. its not often enough cuz I have a decent solar set up. but I intend to set up dc fan. all of this new stuff was pricey but after all my experiences its going to be the best under the circumstances. no way could I get a septic set up on this hill…..however….i did set up a backwoods septic on a little trailer im renting. let me know if you want to know about that.

fin.

quid_non · September 2009

Re: composting toilets - AC or DC or NE?

Interesting comments -
We have an envirolet self composter we have been using for over 2 years - no issues. Found it used on Craigslist for ~$500. It was an AC model, I pulled out all the electrical and replaced w two 12V DC / 0.25amp brushless muffin fans drawing a total of ~0.5A.

It works fine for two people on a semi regular basis. We visit our mountain shack less in the winter (composting will be non-existent @ the low temps), but never experience any smell or flies. WE empty the "loo" once a year, usually at the start of the "active" season (typically late April). With no heater, too much fluid can be an issue - let the males "pee" outside to control this.

bottom line - depending upon the situsation, these can and do work, but they are not free from all issues.

btw...
From experience we have found that the choice of toilet paper makes a HUGE difference in performance. It needs to dissolve quickly, but do it's job! Typically the BEST paper we have found is "Liquid Gold" available at Walmart stores. It is specifically formulated for RV holding tanks. It dissolves quickly and is comfortable to use. If you use conventional paper, it takes too long to break down and creates a real mess.

icarus · September 2009

Re: composting toilets - AC or DC or NE?

Mike,

Nice compilation!

As for adding carbon, it is absolutely essential. A good thing to add, believe it or not is popped popcorn! It does a number of things, it absorbs water, it adds carbon, it adds air, and allows air to circulate. Finding a stash of stale popcorn might be a problem, we had tons when I was using composters and the pop corn did work well.

I have used "envirolet" toilets and wouldn't give you a nickel for one. I have also used Sun-mars and might give just a nickel. I've also used others none with any great success.

Tony

bobdog · September 2009

Re: composting toilets - AC or DC or NE?

Wow! Never would've guessed I'd get such a good range a responses. I can see that folks have had different results using the several methods of waste removal/containment mentioned.

I should state that 1) We can't have a septic system as our lot is too small for NM code + not enough room, 2) Outhouses are a problem (and illegal) where we are, to start with, as most people in the small community (~45 cabins) have them. We all live within 50 yards of a small creek and the water table is approx. 10'-15' below surface. The outhouse problem is so bad that we can't use our well without copious amounts of bleach. The creek is not much better, so needless to say another outhouse will not be going in and 3) I'm a fisheries biologist and it turns my stomach to see outhouses and how they damage the aquatic environment, surface and sub-surface. The "extra" species of algae in the creek this year were amazing and due to the pit toilets entirely! In a dryer place or one with a deeper water table they may be OK, but not in our situation.

So, the only real options for us are buckets and carry out (not going to happen long term) or a composting toilet. That's not to say a $1K-$2K investment is necessary, but an on sight toilet that is off-grid and used "on weekends" is about the only option left. Whatever we decide on, it certainly appears I'll have to work with it to get it working optimally.

And like many things, the brand or style you choose can be a crap shoot as to whether or not it works "best". Unfortunately, too, is that more knowledge is not always for the better as now I'm more confused as to which one to build/buy. BUT, such is life.:cool:

Thanks to all that had something to say. It will all be very useful. I just couldn't exist at the cabin with out this list.

BTW - if anyone wants to sell us the composting toilet they don't like, just let me know. I'll begin my bids at Tony's prices; 5 cents I think it was....;)

bobdog · September 2009

Re: composting toilets - AC or DC or NE?

icarus wrote: »

Mike,

Nice compilation!

As for adding carbon, it is absolutely essential. A good thing to add, believe it or not is popped popcorn! It does a number of things, it absorbs water, it adds carbon, it adds air, and allows air to circulate. Finding a stash of stale popcorn might be a problem, we had tons when I was using composters and the pop corn did work well.

I have used "envirolet" toilets and wouldn't give you a nickel for one. I have also used Sun-mars and might give just a nickel. I've also used others none with any great success.

Tony

I'm curious which models you used from the 2 companies mentioned? I have no clue as to which one would be least or most useful/useless. Also, how long ago was it that you used them? Could they be any different today?

Love the popcorn advice. We eat tons and if I can pry it away from my wife's hands, we may get some into a toilet some day.....

icarus · September 2009

Re: composting toilets - AC or DC or NE?

I used every model of envirolet. The Portable unit, the non electric, the 120vac dry, the 120 vac low water. The electric versions all work,,, with limited use, as long as you have power available. The non electric didn't work at all, and the 12 vdc unit only worked when I introduced propane heat to it. Additionally you have to tend them every couple of days, and the raking mechanism on the envirolet doesn't work very well. The low water (which is just a normal envirolet composter coupled to a marine toilet, you can buy at any marine store probably cheaper!) actually works better than the no water. As you use the toilet, the paper is (fairly) dry, and some water is needed to keep the "compost" moist. So a little water is actually a good thing. A better thing is to reduce or eliminate the amount of paper. A number of women in a household using the toilet can lead to a over abundance of paper with an under abundance of brown.

The issue with the non heated units is that for more than one person, they can't evaporate liquid nearly fast enough. You then go to empty them, and instead of nice fluffy compost as advertised, you are left with a slurry of turd tea that is truly discusting! (Sorry to be so graphic but the truth hurts!)

I can't remember which sun mar I used as it has been a while.

It sounds like in your neighbourhood you have a case of too many people an not enough forethought to sanitation. I understand how poor or overused outhouses can cause trouble, but in most cases the problems are only magnified by using septics instead. Perhaps it is time to bite the bullet and organize a community sewer district, asses every one and do it right.

Good luck

Tony

Cariboocoot · September 2009

Re: composting toilets - AC or DC or NE?

To be fair (and technical), outhouse do not "damage the aquatic environment, surface and sub-surface" per se. Properly done they are the one of the best methods of waste disposal. It's that "properly done" part that's the trouble: improper waste disposal of any method is bad for the environment. Every one of the 50 cabins on this lake has an outhouse, and yet the water here is the among cleanest of any lake in BC. (It is tested every year by the lake association.) The worst lakes are those with cattle grazing allowed around them; the run-off raises the E. Coli count tremendously.

But if you put it too near the water or where the groundwater is too high, et cetera, then you might as well just be using the water itself.

bobdog · September 2009

Re: composting toilets - AC or DC or NE?

Cariboocoot wrote: »

To be fair (and technical), outhouse do not "damage the aquatic environment, surface and sub-surface" per se. Properly done they are the one of the best methods of waste disposal. It's that "properly done" part that's the trouble: improper waste disposal of any method is bad for the environment. Every one of the 50 cabins on this lake has an outhouse, and yet the water here is the among cleanest of any lake in BC. (It is tested every year by the lake association.) The worst lakes are those with cattle grazing allowed around them; the run-off raises the E. Coli count tremendously.

But if you put it too near the water or where the groundwater is too high, et cetera, then you might as well just be using the water itself.

It's nice to hear that there are pit toilets that can function near water w/o contamination. Just from curiosity at differences in levels, I would love to know what the E.coli and nitrate/nitrite levels are around your lake. It would be interesting to compare them to what I have found on our stream/well(s). What's also interesting is some folks actually drink the stream water. My guess is their gut flora is more in line with the water than mine. And fortunately there is no livestock grazing upstream or within several miles downstream.

And I agree that any waste method that is poorly done is also poor for the environment. I remember Santa Monica bay being closed often due to overflow of the L.A. sewer plant(s). But, my issue is E. coli and the stream/well are at high levels; the well being even higher than the stream as fresh water flow is higher in the stream. A good septic system is far better for the environment than a pit toilet, but a poor septic is no better than a poor pit toilet.

I agree that a community system with a wetlands designed properly would be great, but the homeowners can't even agree on new covenants let alone a project of such magnitude. We are, after all, the 3rd poorest state and the least ejukatid....;)

icarus · September 2009

Re: composting toilets - AC or DC or NE?

With no scientific evidence nor background to support my theory, and not wanting to argue any more than this intuitively I have to disagree with the statement that e septic is better than a pit toilet.

All else being equal, two systems that each introduce black water/fecal material into the ground and ground water, how can the one that introduces orders of magnitude LESS black water be safer?

Every one knows that if you have septic, you add dish water, shower water, laundry water to human waste water, thereby greatly increasing the VOLUME of water that is subject to coliform/e-coli etc.

It seems to me that a well designed/built pit toilet, above seasonal water tables etc can't help but be better. That said, out houses that are built too near water courses/lake and stream shores, or in high seasonal water tables are asking for trouble. THAT said, a septic system in the same location would, imho, be a bigger contributer to the above problems for the above reasons. In short, if you have good enough ground for a conventional septic, you certainly have good enough ground for a pit toilet. This also assume that people only put into the outhouse that which it is designed for. I have seen people plumb kitchen drains, laundry drains and all manner of other drains to their outhouse pit, thereby making the situation worse.

This of course does not include exoitic pressure mounds, pump tanks or other exoitc systems that I don't know about.

Tony

Just a though.

Cariboocoot · September 2009

Re: composting toilets - AC or DC or NE?

Civil Engineers used to say: "The solution to pollution is dilution". If you reduce the ppm enough, harmful substances become less harmful. Trouble is, they're still harmful.
Now they say: "The solution to pollution is evolution". Meaning you have to change the nature of the contaminant so that it isn't harmful. This is not so easy to do.

Photowhit · September 2009

Re: composting toilets - AC or DC or NE?

I'd argue that to systems designed to remove/reduce the volume of contaminates would be best. Lagoons, composting toilets, and aerating septic systems all are active at reduction/removal. Some additives to septic systems also help break down contaminates.

I'm not sure a pit does anything to break down waste.

icarus · September 2009

Re: composting toilets - AC or DC or NE?

I can state from real life experience, too much in fact, that outhouse pits, that are given some biologic activity from either introducing proper bacteria, or having earth contact such that natural bacteria can "eat" the solids, out houses reduce their volume by about 90% with in a year or so. An outhouse in seasonal use (say summer) that is allowed to "lie fallow" will be perfectly benign by the next summer. I have had the "pleasure" of shoveling out many outhouses over the years, and I can state with certainty, I would rather shovel out a fallow outhouse than clean out a poorly running composting toilet.

Understand that an outhouse that is used 24/7 365 is another matter. We rotate every few years between a couple and that works great. Our outhouse pits are ~100' from the lake shore, about 6' deep on average, in coarse gravel on top of Canadian shield granite bedrock. We have had our lake water tested annually by the Ministry of Health for over 50 years. It has always tested ZERO coliform, ZERO e-coli and has never had any other issues as far as the Ministry is concerned. We are blessed that we only have 2 year round dwellings and 5 seasonal on a lake that is 15 km long, and is a head water lake.

Tony

bobdog · October 2009

Re: composting toilets - AC or DC or NE?

I'll further add that the toilet, or method of waste removal, will be at a seasonal cabin. And by seasonal, I mean 10 day trips maybe 3-4 times a year. The rest are 3-4 day trips 4-6 time a year. So, in an average year we might use it 60-75 days or so with weeks in between. I can't imagine (but don't know for sure; hence why I started the thread) that a composting toilet won't work under those conditions.

Does anyone else have such experience with any brand of C-toilet and NOT have success?

I am curious that if pit toilets are illegal in most states, including NM, how is that so many people seem to have them?

Tim

icarus · October 2009

Re: composting toilets - AC or DC or NE?

For occasional use I would think that most brands would work well enough.

As for the pit toilet legal issue. I would GUESS (only a guess) that pit toilets have been banned more for political/socio-economic perception issues as I suggested before. The reason they are so common is they are easy to build, and fly "under the radar" of many local jurisdictions. Who bans them, health dept? Building dept? If the health dept bans them, but the health depart doesn't have an active or large enforcement arm they just stay there. They are too small to fit the "category" of a "building", 120 sq ft.

Good luck with your search and your project,

Tony

mike95490 · October 2009

Re: composting toilets - AC or DC or NE?

Mendocino County allows the use of "rural" systems, such as composting toilets/pit privies, in combination with gray water systems
http://www.co.mendocino.ca.us/eh/pdf/LU_FORM4228.pdf
Not all areas have banned them. Ther are specific setbacks from surface waters, wells and property lines, 10 acres min parcel size.

bobdog · June 2011

Re: composting toilets - AC or DC or NE?

I know this is old as dirt, but I thought I would update everyone who may be interested in this thread.

We installed the toilet 2 weeks ago. I installed a 4" PVC pipe from the unit's top through the roof about 4 feet up. We also put a T on top with screen covering the outlets to help keep outside flies out of the toilet. Of course that only works on flies bigger than the screening.

Following the directions that came with the toilet, we put the bulking agent and bio starter in the holding tank and then sprayed the entire inside with their Bio Quick agent.

We then used it.

Before we left, we put a quart of water on it and turned it 4 times per the instructions.

When we came back this past weekend we were pleasantly surprised that it seemed to work as described. NO SMELL. So, we used it more this weekend and turned it again before we left.

However, all was not well. We noticed on Saturday that a urine odor had started to seep into the room. Long and short of it, I had turned the fan/heater on and we believe that 2 things were wrong. 1) the heater warmed up the urine and thus the smell and 2) my plan of having the fan blow out the 4" stack is not working. I won't go into details but needless to say it was likely blowing through the seat and into the room and not out the stack. It should be sucking through the seat and blowing out the stack, not the other way around. We believe this to be the case since when I turned the fan/heater off and aired out the room, no smell.

So, I have some work to do on my configuration, but so far we are pleased to NOT be sitting over a bag on a very small plastic stool.

If anyone is interested any further I'll keep this thread going. We will be going back up to the cabin in a few weeks for an extended stay and that will be the real test as to how it performs.

Tim

Photowhit · June 2011

Re: composting toilets - AC or DC or NE?

Thanks for the update, I should hook up perminatly my composting toilet by the end of summer. I should contact my friend who was sucsessful using a biolet in a camper while building his barge boat and transfered it to the boat. Perhaps I can get an update on his system.

SCharles · June 2011

Re: composting toilets - AC or DC or NE?

Well, I am interested, so keep posting.

We have a SunMar and it's been installed since the early nineties. I rarely use the heating element. The overflow tube runs through the base of the wall to the outside and into a hole I dug. It only overflows when we have guests for more than a few days, which is almost never.

I plugged the heating element cord into a switched outlet, so I only turn it on when I have lots of extra electricity from our PV system. Again, I rarely turn it on.

I replaced the 120 v. fan that came installed with a brushless DC fan [12 v.] and have it controlled by a rheostat. I leave the fan on 24/7 and throughout the year will adjust the fan speed depending on, again, how many people are here. The SunMar fan install is designed to blow air out the exhaust pipe, so I simply put a different fan in the same spot. The replacement fan was a slightly smaller size, physically, so I took a piece of Lexan or whatever it was and used that to make a mount I screwed into place, no air leakage around the body of the smaller fan.

We just do not have odors indoors. I don't recall the electrical spec's on the DC fan, but it uses very, very little electricity. It has been running for about 20 yr.

There are two of us living here and using the compost toilet. Our model is one of the self-contained units, without the large chamber beneath the floor. We have a low crawlspace, for one thing, and it gets very cold here for months at a time, well below freezing and sometimes well below zero. The crawl space is not heated, so having a container down there would be a disaster in winter. The self-contained unit solves that issue, but I am certain that, for full-time use, it is only big enough to be used by two adults without frequent emptying. For a larger household, I would strongly recommend the large units with the separate chamber in the basement or, in southern climes, outdoors in a shed build against the wall, or whatever.

For the 11 yr. I lived in a cabin prior to building this cottage, I had an outhouse, grandfathered in because it was already there at the old mining cabin. We are not allowed to build or use them on newer construction unless the pit is lined with concrete and the owner agrees to frequently have them pumped out, regardless of whether it is needed yet. Very expensive on a regular basis. I don't know that anyone from the county or state every checks on that frequency, never heard of it happening, but one cannot get a building permit or get the construction signed off with a privy. Too bad, I was happy with mine at the other place.

The compost toilet is one answer to the waste thing, but these appliances need some regular attention. Or, they do up here where the temp's are cold half the year. It isn't the end of the world, but for some people it is a task they'd rather not have to deal with.

Polychrest · June 2011

Re: composting toilets - AC or DC or NE?

We installed a SunMar NE at our summer place last fall. I bought the 12v fan and installed it in the stack as per the manual, and hooked it up to its own dedicated 12v battery/charge controller/30-watt panel. This spring my wife and I began using it, with no hiccups so far (knocks on his head).

We went with this this model based on the experience of neighbours on our lake who've been using an NE with few problems for four years now. Their blooming flower beds are the only noticeable evidence that human waste composting happens at their place.

One lesson they shared with us: don't try and save a few bucks by making your own bulking material to add to the composting drum. The SunMar product composts way better than the garden centre peat moss and wood shavings combo they tried last year.

I'll update this as we use our throne more heavily.

System2 · June 2011

Re: composting toilets - AC or DC or NE?

Nice Thread, good for you...

My family and I have used a Sun-mar on and off for the last four years. I much prefer the concrete lined 4 section outdoor composter, less maintenance.

As for the indoor toilet, the DC fan runs non-stop. Have never needed the heating element, mostly we #1 outside somewhere. Watch out for the peat, it seems to just jam up the knives, and my kids just use too much TP!! The tp isn't a problem outside,
it breaks down fine.

The outdoor composter is on a four year cycle, and the four year old stuff is some of the finest s&%t I've ever seen. Honestly I'm not looking forward to having to deep-clean out the the indoor unit.

Good luck

westbranch · June 2011

Re: composting toilets - AC or DC or NE?

Interesting concept, never heard of a 4 bin - 4 year outdoor privy. Why concrete? As long as #1 is elsewhere there should be no need for lye/lime to 'sweeten the pot' so to speak...

Is there a source for plans or whatever?

thanks,
Eric

composting toilets - AC or DC or NE?

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