Alternative head

[knutfg]

I am in the process of making installations in the boat. One item I do not like at all is the traditional marine head with required holding tank. The tank takes space, it is a risk of not so funny work if ANYTHING goes wrong, the system requires a through-hull (each one is a risk) and the mechanisms of the system are sensitive and smell is part of the game.
I have come across at least a couple of products based on composting the solids. Especially one of these products is very compact and the manufacturer presents quite convincing arguments why this is a viable system. I would love to avoid the normal head, but before doing so it is of course interesting to know if anyone else has already practical experience? Positive or negative?
(If anyone needs details about the two products I have found so far, pls send me an email and I will forward).
I am eagerly waiting for possible response.
Knut



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[HeadMistress]

Which ones are they? Hard to know what the pros and cons are without knowing which systems you're inquiring about.

<hr width=100% size=1>Peggie Hall
Specializing in marine sanitation since 1987

 

[robind]

Spam alert???
Rob

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[knutfg]

The most promising alternative (as far as I have been able to find out so far) is the Air Head Dry Toilet. One reason why I am leaning in this direction is the dimensions of the unit, being about the same as a normal marine head. Information can be found under:
http://www.airheadtoilet.com/Air_Headx.html

The other unit I have looked at is a bit more bulky and will also use more electric energy, so I don't see any reason to refere to it.

However, I am not really asking for pros and cons since those are pretty clear, provided that a composting system works according to information presented. This is the sticky point (info from the seller is not always complete and accurate) and the reason why I ask if anyone has actually installed any of the available composting systems. I am hoping to get real life users information about how it has worked in reality. I may be interested enough in the pros to be the guina pig myself, but if I can reduce the risk, or find out that it is not a good idea without installing it, this is of course better.
Knut

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[HeadMistress]

I know several people who've installed the Airhead http://www.airheadtoilet.com/Index/Page_1x.html) and seem to like it. The only downsides to it are:

1. the blower and heater must run continuously, so it needs a continuous source of power--and despite mfr's claim, more than a small solar panel can supply to keep the battery sufficiently charged. If your boat is in a slip connected to shore power, no problem...but if you keep your boat on a trailer or a mooring, keeping the battery charged WILL be a problem.

2. urine collection and disposal. Urine is collected in jugs that must carried ashore and dumped down a toilet...they can't legally be dumped over the side in any waters where a toilet marine toilet could not also be legally discharged overboard. According to the mfr, each jug will hold 4 days' output per person...which means two people will fill a jug in two days...a family of 4 will fill a jug a day...you must take guests into consideration in this equation too. They have to be stored somewhere aboard unless you're at sea where you can just dump them over the side. The only alternative to the urine jugs is to install a holding tank for urine...in which case you gain nothing over the usual toilet/tank installation (if you think urine doesn't stink, you're wrong!).

So between the power requirements and the urine storage, the Airhead may not offer much of an advantage over a portapotty on some boats in some waters.

Other composting toilets have the same or even greater power needs, and excess liquids present an even greater problem than with the Airhead....they're not drained off separately, so require frequent application of rather large amounts of peat moss (peat moss is the recommended material because it's highly absorbent and also breaks down quickly...people who've tried to substitute sawdust and other materials have found they don't break down easily and cause problems). They're also highly temperature senstive...don't work at all in cold weather because bacterial activity needed to break down waste gets increasingly sluggish below 75 F...becomes so sluggish below 60 F as to be ineffective...and go totally dormant below 40 F. Temperature could also be an issue with the Airhead.

The Airhead and other composters are also very expensive compared to other systems...I don't know what they sell for in the UK, but here in the US, the Airhead is over $700 USD including shipping...the Sun-Mar Marine "Elcolet" composter is over $1200 USD.

So IMO, the Airhead and other composters COULD be a viable alternative to a traditional marine toilet and holding tank on boats that a) are on "no discharge" waters, and b) have sufficient power resources to allow the system to work as it must work to perform as advertised...but I can't see much advantage to any of 'em n coastal waters or open sea where the toilet can be flushed overboard except on rare occasions. Otoh, most people who have them like them. So it's your boat, your money...and therefore your decision.

<hr width=100% size=1>Peggie Hall
Specializing in marine sanitation since 1987

 

[snowleopard]

with due respect to the experts, isn't the sea the world's most efficient composting system?

put it in a holding tamk till you go offshore /forums/images/icons/smile.gif


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[knutfg]

Thanks for the response. Certainly quite a few elements that are food for thought in what you write. I will work my way through the pros and cons another time and see what conclusion to make. Not unlikely that the std solution wins, since constant draw on the batteries and increased need of charging may soon spin off negative consequences that I don't like to think about.
Knut

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[HeadMistress]

Knut, what are your anticipated needs in terms of capacity...usual number of people continuously aboard for how long? There are other alternatives to the ubiquitous marine toilet and holding tank that don't require any power and with some creative plumbing can be flushed and emptied without any additional thru-hulls.

<hr width=100% size=1>Peggie Hall
Specializing in marine sanitation since 1987

 

[knutfg]

Mostly 2 people for constant live-aboard and we hope to have guests at intervals, but probably not more than 2-3 people for any duration (week or so). Of course, for a night or a weekend there might be 4 to 6 extra occasionally. We are planning on 6 permanent bunks, but not for permanent use. Boat is 35'
Knut

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[HeadMistress]

Rats...I was hoping you'd say 2 people, weekends only...in which case a self-contained system such as a permanently installed 5-6 gal "portapotty" fitted for pumpout would solve your problems very easily...holds as many flushes as a 15-18 gal tank connected to any marine toilet, but no plumbing except a pumpout line and deck fitting and a vent to the outside of the boat, unless you also want to be able to dump it at sea...in which case, you'd need to add a y-valve and macerator pump to a thru-hull.

However, since you seem to be willing to spend a few hundred pounds for something like the Airhead, I suggest you check out the Raritan Lectra/San. It's an approved treatment device that can be used with any toilet, legal in all waters except those specifically designated "NO discharge," and the most environmentally benign way to deal with onboard waste in existance. It treats and discharges a flush at a time...uses no toxic chemicals, but instead creates hypochlorous acid (a type of chlorine) by charging the ions in salt water with electrical current. During the treatment cycle, it kills bacteria...but when the stimulous (current) is removed, the solution reverts back to salt water, so no free chlorines go into the water. It's also so effective AND benign that it would require 1000 vessels, all equipped with Lectra/Sans, sitting in the same place for 24 hours to equal the negative environmental impact of just one dumped holding tank. Yes, it will require that you have a discharge thru-hull below the waterline...and it must use salt water (though that can be solved without necessarily using sea water)...but compared to the convoluted system of plumbing, y-valves, macerator pumps etc required by a holding tank, it's the simplest solution.

You'll find all the specs and info on the Lectra/San here: http://www.raritaneng.com/products/waste_treatment/lectrasan.html

Don't let the power consumption numbers scare you...1.7 AH/flush seems like a lot till you realize that total daily consumption for 2 people is only about 17 AH/day...well within what any adequately powered boat can handle.

I'm a BIG fan of the Lectra/San...it's durable--has been on the market here for 30 years and some of the original units are still in service, reliable, requires almost no maintenance, and the plumbing is simple. I also see no need to store waste aboard in ANY form--composted, in a tank, or incinerated (you do NOT want an incinerating toilet!!!)--if it can legally be flushed overboard without any harm to the environment whatever.

Sp check it out and get back to me with any questions.

<hr width=100% size=1>Peggie Hall
Specializing in marine sanitation since 1987