Peggie Hall wrote:
Helbergon wrote:

What are your thoughts on the airhead toilet "www.airheadtoilet.com"
for a cruising boat.
I'm refitting my 37 footer and looking at the diferent optiond for
marine heads, although the price of these units is steep my question
is if they really work or are they worth the price tag ?


Why store waste aboard if you don't have to? Composters and systems like
the Air Head (which isn't really a composter, but a dessicator) may be a
good alternative to holding tank on a "no discharge" inland lake, but in
coastal waters where the discharge of treated waste is legal, it makes
more sense IMO to install a Type I MSD (i.e. Lectra/San) for about the
same price and the same, or even lower, power requirements...’cuz the
fans and heaters in composters/dessicators must run continuously to
maintain an aerobic--and therefore odor-free--condition and evaporate
the liquids in solid waste...whereas a treatment device only needs power
for a couple of minutes after each flush.

Liquids (urine) are the major issue in these systems. .They cannot
legally be drained overboard inside 3 miles, so they must be held aboard
in something—in the jugs provided with the Airhead, which must be
carried ashore and dumped, same as a portapotty…or in a holding
tank...and if you have to have a holding tank to store the
liquids--which, btw, present just as much of an odor control problem as
fecal matter--what's the point of having a system that separates urine
from solid matter? Especially when you consider that solids don't take
up that much room in a holding tank. A gallon of urine every 30 hours =
5.6 gallons of urine a week. Doesn't sound like much because it's
undiluted by flush water...but the odor-causing properties in it are
also undiluted.

And there's something else to consider: temperature. Because a certain
level of bacterial activity is necessary for these systems to at all,
and because bacterial activity starts to get VERY sluggish below 60
degrees F and goes completely dormant at 40, they don't work very well
when the temperature is below 50 F. Since the Airhead doesn't actually
compost, but only removes all the moisture from solid waste, this may or
may not be an issue for winter liveaboards in cold climate zones, but it
definitely is for true composters unless the unit is heated continuously.

And, there is the matter of power...the system can't work without any,
so it must run 24/7/365--whether you're aboard or not...and power can be
hard to come by if you keep your boat on a mooring, or on any boat that
isn’t connected to shore power.

So if someone who owns a houseboat (those floating mobile homes on barge
hulls that litter the inland lakes and rivers) were to ask me if I
thought a composter or the Airhead is a good idea, I'd say it's
definitely an option worth considering...but on a sailboat in coastal
waters—especially where the discharge of treated waste is legal—I think
a Type MSD makes a LOT more sense.



Peggie, how do you rate dosing a regular holding tank with bleach as
a treatment prior to dumping? Do you have a recipie?

Terry K