Sun Mar composting toilets

John_M · April 23, 2008, 09:38:57 AM

Anyone have any experience with the Sun Mar composting toilets? I just got a brand new one for free and it seems really great. It looks like it will be the perfect temporary system until I get my septic installed in a year or two?

I tried doing a search on this site but didn't come up with anything. I thought there was a discussion on these awhile back?

MountainDon · April 23, 2008, 12:26:45 PM

The Sunmar has been mentioned by a few folk with experience with them. Everything I recall was favorable. However, I don't recall there being much in the way of follow ups.

Here's one thread...
http://countryplans.com/smf/index.php?topic=2983.msg50416#msg50416

April 23, 2008, 08:20:59 PM

I have one and have been using it for almost three years as I build my house. It has served a family or 4 with occasional extras. Its OK - but only OK. Make sure you install the overflow hose as the consequences are disasterous if you don't. Also, its not true to say they don't stink. Or maybe that's my management of the system that is at fault.

On the uspide, they are very easy to install and the compost product is wonderful for establishing your garden.

Would I buy it again with my time over. Probably, but only for the easy install.

Cheers

Robbo

considerations · April 23, 2008, 10:08:47 PM

"I just got a brand new one for free"

For free? That's 1 or 2 grand of toilet, depending on the model. I'll have to cough for one soon, or face the plastic privy for one more winter.

A composting toilet much less expensive than the fancy double-tank-electric-pump-pressure-fed-kitty-litter-mound they want me to build out here. ($20K +/-) With no bypass for electrical outages...do you believe that? I asked the company I hired to site and design the system about what to do during an electrical outage. They said, well, you have about 3 days..three days before what? I asked. Three days before it starts to back up. wonderful.

So, I'm off grid, never lose power. and the grid goes down often around here, sometimes for a week or two....but an indoor toilet is high on the list.

MountainDon · April 23, 2008, 10:29:14 PM

That's one of the things generators are for.

April 23, 2008, 11:01:09 PM

I have two, a little one for when the solar panels dont see enough sun to run things and keep a charge on the batteries, and a big one to run the washer, and the dryer in the winter. I'm trainable.

MountainDon · April 23, 2008, 11:04:04 PM

Which model Sunmar are you going to get? Self contained? AC, NE or AC/DC?

glenn kangiser · April 24, 2008, 12:22:38 AM

Not sure about the septic system you are doing, considerations, but you may be able to put a bigger reservior tank where the pump is for a longer time, but -- it will still have to have something done to get it power soon. We did one with a ferrocrete tank for one of my customers. (Several layers of chicken wire and extra strong sand cememt mix and cast ferrocrete top...}

considerations · April 24, 2008, 01:59:55 AM

I'm not sure about the septic system I'm doing either. It's just going to wait till I can concentrate on it.
In the meantime, my portajohn does have advantages. Some one cleans my bathroom every week without fail.

April 24, 2008, 07:22:53 AM

Quote from: John_M on April 23, 2008, 09:38:57 AM
Anyone have any experience with the Sun Mar composting toilets? I just got a brand new one for free and it seems really great. It looks like it will be the perfect temporary system until I get my septic installed in a year or two?

I tried doing a search on this site but didn't come up with anything. I thought there was a discussion on these awhile back?

I know...I was really lucky. It pays to know people I guess. It is the Excel model. It costs about $1500 on most websites. I will let everyone know how it works throughout the summer months! It is good to have unbiased opininions and I think it is a product that a lot of people on this site would be interested in! I just hated emptying those portable camping toilets with all that blue deodorizing liquid.....yuck!!

MountainDon · April 24, 2008, 09:46:45 AM

Excel as in the one that needs AC power (has a 120 VAC fan and heater, small vent pipe out back) ?
OR Excel NE (NO fan or heater, larger vent pipe, out top) ?
OR Excel AC/DC (12 VDC fan, NO heater, large and small vent pipes)

Curious.

John_M · April 24, 2008, 11:40:31 AM

Quote from: MountainDon on April 24, 2008, 09:46:45 AM
Excel as in the one that needs AC power (has a 120 VAC fan and heater, small vent pipe out back) ?
OR Excel NE (NO fan or heater, larger vent pipe, out top) ?
OR Excel AC/DC (12 VDC fan, NO heater, large and small vent pipes)

Curious.

It is the Excel that runs on electricity (115v, I think). The electricity allows the fan to intake air to reduce odors and the evaporating chamber is heated to allow liquid waste to evaporate through the 2" vent to the outside.

MountainDon · April 24, 2008, 12:30:31 PM

OK. That works fine as long as you have 120 VAC in good supply. I believe it's not the best model for off grid. I will be very interested in your experiences with it though.

We're off grid and likely to be picking the AC/DC model, as at times there may be an electrical surplus and other times there won't.

hnash53 · April 29, 2008, 09:58:39 PM

Quote from: Robbo on April 23, 2008, 08:20:59 PM
I have one and have been using it for almost three years as I build my house. It has served a family or 4 with occasional extras. Its OK - but only OK. Make sure you install the overflow hose as the consequences are disasterous if you don't. Also, its not true to say they don't stink. Or maybe that's my management of the system that is at fault.

On the uspide, they are very easy to install and the compost product is wonderful for establishing your garden.

Would I buy it again with my time over. Probably, but only for the easy install.

Cheers

I'd like a little more info about the overflow hose. I've read this is to drain off urine and into a properly constructed gravel bed and overlaid with soil, etc as described on Sun-Mar's site. It sounds like it helps from what you say.

You also said that it still smells. You have a vent pipe, but do you have the small electric vent fans installed in the pipe?

Thanks for any help you can provide.

Hal

Robbo

April 30, 2008, 03:53:16 PM

Quote from: hnash53 on April 29, 2008, 09:58:39 PM
Quote from: Robbo on April 23, 2008, 08:20:59 PM
I'd like a little more info about the overflow hose. I've read this is to drain off urine and into a properly constructed gravel bed and overlaid with soil, etc as described on Sun-Mar's site. It sounds like it helps from what you say.

You also said that it still smells. You have a vent pipe, but do you have the small electric vent fans installed in the pipe?

Thanks for any help you can provide.

Hal

Hi Hal

Yes it does still smell a little but usually when the wind is blowing from the wrong direction. This is in spite of the fan which is installed. However, I think I could solve the problem by fitting a taller vent pipe, but too many other thngs to do at present.

So far as the drain goes, ours operated well for about a year without it connected and we thought all was well. We the had a spell of cool wet weather and this meant that the faeces and urine didn't dry out and the whole thing overflowed. Lovely!!!!!!!!

But it was easily fixed with a 1/2" poly pipe run into a small gavel bed, well hidden under a rose garden. It doesn't have to be big - about 2 foot square. Just enough to get the muck out of gthe house in a way thats not smely or unsightly.

Hope this helps. Robbo

hnash53 · April 30, 2008, 09:15:06 PM

Hey thanks, Robbo. I thought I'd design the field as described in the Sun Mar site. We have a lot of wind from the west where our cabin is, and thought I'd put in the fan at the top of the stack as well as the 12v fans in the vent pipe itself. Seems that would take care of things.

MountainDon · April 30, 2008, 11:06:45 PM

One thing to remember with the 12 VDC fan is that when it is placed in the vent pipe it will act as an obstruction to flow at any time it is not powered. Just wanted to make that was understood.

JG · May 01, 2008, 02:46:31 AM

I've looked into the Sun Mar toilets, but the price is a bit high. Has anyone heard of Natures Head composting toilets? The cost is around $850. I know Lehmans is selling them.

http://www.natureshead.net/

glenn kangiser · May 01, 2008, 09:25:39 AM

Thanks for posting that option, JG.

Welcome to the forum.

MountainDon · May 01, 2008, 01:41:15 PM

JG. I had not run across the Nature's Head unit before. Thanks for the info.

There is a major difference in the use of the Nature's Head compared to the Sun-Mar self contained. Correct use of the Nature's Head unit requires user intervention to separate the urine from the feces. The two bodily functions must be separated into two steps. The urine is collected directly to a liquid holding tank and emptied when full. The solid waste goes into the composting drum along with the toilet paper and the necessary peat moss. Some of the other composting toilet brands on the market have the same requirement.

The Sun-Mar self contained unit has a stainless steel mesh in the drum bottom that allows excess liquid to drain into the evaporation pan. That pan has a connection for the aforementioned drain tube. Some, maybe all the liquid may be evaporated, some will be drained off through the drain tube, depending on patterns of use.

The Sun-Mar AC unit uses a 1/2" drain tube, the NE (non-electric) and AC/DC units use a 1" drain tube. The air vent on the AC is 2" out the back (AC power driven fan at all times) whereas the NE has a 4" vent out the top of the unit back section, and the AC/DC has both. The NE has the 12 VDC fan as an option and the AC/DC includes both the Ac and the DC fans as well as the AC heater.

For anyone looking at the Sun-Mar Cabela's sells some of the Sun-Mar models at pretty fair pricing.

May 01, 2008, 04:34:30 PM

As for the the 12 volt fan in the vent, I was planning on having it run pretty much fulltime. I might even have a dedicated solar panel and battery for it.

What do yall think about that idea?

Hal

MountainDon · May 01, 2008, 04:52:27 PM

Sounds good Hal Either way I mean. Though a separate panel/battery would need another controller. $:-\$

hnash53 · May 01, 2008, 05:08:35 PM

I just checked Nature's Head and they have some solar powered vents that move 1000 cu ft of air per hour, or about 17 cf per minute. That seems pretty significant. Plus they say the vents will run for 48 hours with no sunlight. Might be a good solution.

As for the separate solar panel and battery, if the battery is big enough (amphours) and the panel is small enough, it's possible to not need a controller.

MountainDon · October 22, 2008, 11:52:40 PM

Update: After a few months of using the SunMar we are basically happy with it. We have the AC/DC model. It is set up with both the 4 inch convection vent and the 2 inch AC powered fan vent. It simply sits there in its temporary place in the shed. It will be moved indoors eventually. We've never been bothered by odors and as far as I can tell the liquid overflow tube has never been called into action. It is setup so that the AC heater and fan are activated whenever the generator is running. At other times the convection system works well. I can attest to that because I placed my face directly over the 4 inch vent outlet when on the shed roof one day and was rewarded with a distinct odor. Nothing inside the shed though.

The composting action slowed down when the cool/cold fall weather hit. I have transferred some of the compost-to-be mixture to a plastic drum for overwintering. I don't know if this is going to be a problem; we'll see. The deal is that over the winter the contents of the drum will freeze and with it in the outdoor shed, probably not get much of a chance to thaw. So I emptied most of the contents to a drum for future warm weather composting. That way we can continue to use the toilet when we go up on weekends.

rdzone · October 23, 2008, 11:16:57 AM

MountainDon,

funny I just had a long discussion with a friend of mine about his biolet composting toilet. He has a remote cabin here in Alaska and loves his toilet no more outhouse. As you have said no problems with odors and he has his inside the main cabin. Since you have generator power at times, same as he does you might want to use his little trick. His toilet also freezes while he is gone, but once he arrives he starts the generator and has a little heater next to the toilet which he fires up. He said after a hour or two things are thawed out enough to be able to turn the mixing knob. He makes sure he mixes things up well before he leaves and has no problems over the last 5 years or so.