I have mentioned the composting head in Galena before, but never fully explained it.

So here goes:

My friends on s/v Wandering Albatross have a composting head from Air Head (you can read all about at this linked site). I was impressed with it for several reasons.

S/V Wandering Albatross, another Westsail 32, was the first boat I'd ever been on where there was absolutely no order from the head and/or holding tank.

Secondly, the air had has no holding tank and that meant more space for storing important stuff like food and tools.

And finally the system was simple with only one part that could possibly fail: the exhaust fan. No joker valve to get clogged. No pump to rebuild. There is no waste plumbing to replace or clean out. And never having to find a pumpout station is not a small advantage.

I purchased my Air Head in the summer of 2005 and have been happy with it every since.

Installation was a bit of a chore since the Air Head is a bit bigger than the small commode that was in Galena.

First I removed the existing commode and the associated plumbing and holding tank (smelly, messy job). Then I positioned the Air Head. Right away I noticed a small problem. The existing head sat on a small raised platform that was part of the floor mold. The extra height of the Air Head made it very uncomfortable to sit on, even for me. And I knew Jane would have a hard time. I could put my feet on either side of the commode but that, too, was uncomfortable. So I fashioned a small step (visible in the picture below) to give me someplace to put my feet.



The only plumbing required is for a small air vent. The Air Head requires a constant airflow to keep the composting action going. The air also keeps the aerobic bacteria alive and that makes the process almost oderless.



The instructions called for a 1.5" hole to be cut in the cabin top for the vent. I balked at that. I already had a vent in the hull for the original holding tank. I checked the airflow with the 1.5" vent and then with the 5/8" side vent and there was no real difference. The small computer (muffin) fan pushes the air slowly and quietly through the small vent without problem.

But I did need to build a new plenum to hold the fan and transition from the supplied 1.5" hose (which is just vacuum cleaner hose) to the 5/8 vent hose.

I went down the local hardware store and found that the fan would fit nicely inside the big end of a 1"-to-3" PVC adapter. So two of those, with a small bit of 3" PVC to connect the two made up the plenum. They are held together with a sheetmetal screw to let me get at the fan should it need replacing.

Then a couple of standard adaptors to attached the 1.5" line to one end and the 5/8" line to the other and we have the following:

The water line below the plenum is the freshwater line to the head's sink

The air flow is left to right and this contraption is mounted under the vanity to the left of the sink. The 5/8" tubing comes out the right side of the plenum runs through the hole in cabinet divider and out to the through hull.

I put a small loop in the hose between the fan and the through hull vent (under the sink) to catch any water that might come in through the through hull vent. I've found that a small bit of water will block the air flow. While I'm not shy about burying the rail, I've found that the real problem is condensation in the tubing that eventually blocks the airflow.

My solution is to put a catch-bottle in the line. Any water that gets into the hose drops into the catch-bottle, leaving the air line open and unclogged. If I need to I can remove the catch-bottle to empty it. But in a year I've not yet had to do that. I think the airflow eventually evaporates any water in the bottle.


The water trap in the air vent line leading to the side hull vent.
The Plenum is just to the left of this

The only down side is having to 'harvest' the main waste bucket every couple months and having to empty out the urine bucket every couple days. But both are simple chores.