Compost toilets

[Talk Story]

Is there any smell associated with venting?

[valhalla360]

Originally Posted by Talk Story

Is there any smell associated with venting?

Less than from a traditional sess pool tank air vent... (ie: a sewage holding tank)

More importantly, the smell from a traditional head is gone from within the boat.

Smell issues are a huge reason to consider changing to a composter.

[SV__Grace]

Yes, it smells a bit like a garden or farm, not strong (on a scale of 1-10 it's about a 2, maybe a 3 in hot weather).

If you like the smell of a freshly tilled garden you might actually like it! Waaay better than smelling a marine head, especially when the hoses age and start allowing permeation.

Our vent is on the stern so we only smell it on the rare occasion we're at a dock and the wind is coming from that direction.

For a longer vent run to the aft (ours is @20 feet) the manufacturer (we have an Air Head) recommended two inline fans instead of one. They're tiny fans and don't draw much power and seem to work well as long as the bug screens are kept clear.

[Mike OReilly]

As others already said, the main smell associated with these heads is an earthy odour, and it's not strong. Smells like good quality potting soil. If you smell something else (outside of the immediate moments after usage), there's a problem, or it's past time to dump.

[Minggat]

6 years. No vent installed. C-Head

[ejjawhite]

I’ve never gotten any odors while venting a recent or older usage
of the composting head. Then again, my head is 20’ from the cockpit.
I’ve not had any odors on deck near the vent either.

[newhaul]

Mine is not even vented and never had any smells other than fresh ready for planting flowerbed smell

[Heathenly Twins]

Slight thread drift: I have just purchased an Air Head composting toilet but it doesn't come with an outside vent, what's a good vent to install that can be shut completely for nasty offshore weather?

[coopec43]

Originally Posted by Heathenly Twins

Slight thread drift: I have just purchased an Air Head composting toilet but it doesn't come with an outside vent, what's a good vent to install that can be shut completely for nasty offshore weather?

Some makes of compost toilet have a fan for ventilation so they must have a vent, What about a mushroom vent on deck?

Some compost toilets haven't got a "churner" so they must have ventilation?

https://c-headsmartandsimple.com/201...less-versions/

https://www.c-head.com/post/ventilat...s-part-1-boats


I have yet to confirm it bu I think I can pipe the urine directly over-board (a little above the waterline)

[Minggat]

Again, 7 years and no vent with my C Head. But I understand that the Airhead encloses the solids bin to isolate users from the perceived “nasty”. By enclosing the solids bin, some kind of vent is needed to allow for moisture to escape. NOT SMELLS.

Point is, try venting it inside the boat before you go to the trouble of venting to the outside.

Note. Mold gnats are only an indication that your moisture removal isn’t keeping up with your usage.

[Talk Story]

Originally Posted by Minggat

Again, 7 years and no vent with my C Head. But I understand that the Airhead encloses the solids bin to isolate users from the perceived “nasty”. By enclosing the solids bin, some kind of vent is needed to allow for moisture to escape. NOT SMELLS.

Point is, try venting it inside the boat before you go to the trouble of venting to the outside.

Thanks for that - I have a walk in engine room that will be very easy to vent to ... if it smells it can always be relocated to an outside vent.

[Happ]

Check out YouTube Atomvoyager. James rebuilds Alberg 30’s and has a great setup. He provides detail on how he does it. Yes it can be completely shut down in bad weather.

[chriskilmer]

Just took over caretaking duties of a new to me Caliber 38 (with 2 heads). Forward head plumbed for off shore use. Aft Head smell that offended even seasoned sailors!

I was Faced with replacing 22’ of 1.5” quality sanitation hose. Assuming no leaks in the holding tank, this should fix the problem.....maybe.

I researched heavily here and elsewhere. Like Mike says, the vast majority of CH users love them. That was enough for me. Awaiting my Airhead (on backorder). Ordered a mushroom vent from Nature head, to possibly use existing waste outlet for vent (we’ll see, the engine room sounds good, too).

Guess what’s days are numbered: 22’ of waste hose, macerator, holding tank, pumpouts, stink. Making the trip to marina bathroom for nature’s call. I won’t have to share the Watermaker area with what was just mentioned, and will gain extra space!

One project I’m looking forward to.

[Mike OReilly]

Just one thing to keep in mind. C-heads take a slightly different design and functional approach compared to Air/Nature's Head. C uses non-proprietary containers that are about 1/2 the size of those used in the the other two. This means they need to be emptied at around twice the rate. Typically this means C-head users get two to three weeks between main tank dumps (two adults, full time) while the other two typically go four to six weeks.

Air and Nature's achieve this through larger holding tanks, but also through negative pressure via active venting. Isolating users from the perceived “nasty” is not the reason. So while venting is not essential in the two latter heads, it does help them operate optimally. Short term closure of the vents makes no real difference.

Twins, most people use some sort of sealable mushroom vent with their Air/Nature's heads. Some use louver vents, or cowl vents and some even use the solar powered vents. Whatever it is, you should be able close it off. The worst thing that can happen to these heads is if you get a backflow of sea water down through the vent -- ask me how I know .

Minggat is correct about the mold or gnats. It indicates a moisture problem. This is easy to manage with active venting.

[flightlead404]

I'm tying to understand the legalities wrt to composting toilet for US coastal cruising primarily.

I see all the pros and cons listed in this and many other threads but, it seems to me, that primarily you're trading the larger, possibly semi-automated holding tank and pump out mechanisms, with a much smaller manual holding tank process.

That is, if I still can't dump the waste, I still have a storage requirement.

1) Is it illegal for me to pee over the transom? AFAICT its not illegal at least in most places. The laws seem to refer to MSDs and emptying tanks but don't directly talk about peeing over the transom. So, if I can pee over the transom, can I empty the urine container overboard similarly?

2) What about dumping the solid waste? If I'm still tied to a pump out station/marina but now with a much smaller holding tank that might be a bucket or a plastic bag in a lazerette, with much more intimate handling of the waste and much higher likelihood of spillage into my locker, that seems a significant disadvantage.

3) HOW do I dump it? Again, if not overboard then I'm still tied to a marina of some sort. Obviously I can't stick a pump out vacuum nozzle into a plastic bag. Stick it in the doggie waste bin? Marina toilet? Regular garbage can? How exactly do you get rid of the stuff?