Experience with Composting head in High Lattitudes

[lamadriver]

Seeing that there has been some discussion lately on composting toilets again has anyone used them in High Latt environments ( cold)? I understand the concept that there needs to be some heat for the process to work.

Following the other posts , one person commented they use one with out an external vent. Any one else have luck with that? Don't think ill be drilling a hole in my steel deck. If it i just about de-humidifcation how about running it to the bilge or and aft lazerette?

LD

[peghall]

Temps need to be constantly above 70F--ideally at least 75F--for any breakdown to occur because bacterial activity becomes increasingly sluggish as temperature drops. Below 60F, not much can happen...at 40F, it stops. Bacteria don't die at 40F, they just become dormant. Most systems do include a heater, but they need power.

Venting to the outside is necessary 'cuz it's not just about humidity. When organic material breaks down, it generates CO2...you don't want much of that replacing the oxygen in the boat. And although a properly functioning system SHOULD be relatively odorless, the key phrase is "properly functioning" and we all know that anything that CAN go wrong, will. But even if humidity were the only issue, a humid bilge isn't the best idea...warm humid conditions are bacteria factories that are breeding grounds for odors.

If you don't want to deal with a holding tank, depending on where you are a USCG certified Type I MSD --device that treats each flush and discharges it overboard LEGALLY except in waters designated "no discharge"--might be the answer.

[wrwakefield]

Originally Posted by lamadriver

Seeing that there has been some discussion lately on composting toilets again has anyone used them in High Latt environments ( cold)? I understand the concept that there needs to be some heat for the process to work.

Following the other posts , one person commented they use one with out an external vent. Any one else have luck with that? Don't think ill be drilling a hole in my steel deck. If it i just about de-humidifcation how about running it to the bilge or and aft lazerette?

LD

Lamadriver,

We boat between 56°N and 65°N presently. One of our two heads is a composting head. [Nature's Head] It is more of a desiccating head [vs. composting...] with all the same benefits, and for the reasons Peggie already described.

Ours is vented through the deck using a solar powered vent. External venting is important for this unit to work properly, keeps the odors outside if things go sideways [usually when someone allows liquids to mix with the dry bits...] but also during use for solids. No odors in the head while one is using the commode...

Some folks repurpose the through deck fitting originally used for pumping out the holding tank- fitted with a mushroom vent cap- for the vent.

In cooler wx we heat the boat, but not to mid and upper 70s F as needed for composting [at least not on purpose anyway...]

We are very happy with ours after our first year of use. Works great. Not affected by cold.

In case this is helpful.

Cheers!

Bill

[valhalla360]

We use ours in Michigan. Early and late season, it's pretty cold. No problems. Apparently, we have the cold weather bacteria here. While temps above 70 will speed the process, bacteria still function at significantly colder temperatures (ie: your average household septic system averages around 50 degrees year round and the bacteria do just fine)

Venting is best but no, the CO2 isn't going to kill you. The reason for venting is you want to encourage aerobic bacteria which need oxygen. It isn't producing CO2 in large enough quantities to be a concern.

Also, odor is a non-issue as you are creating an oxygenated environment which encourages aerobic bacteria. It's the anaerobic bacteria in holding tanks that create mercamptors which are the compounds that you recognize as the nasty poo smell. If you open a composting toilet up, should smell like potting soil (assuming you wait an hour or two after a deposit)

[peghall]

Venting is best but no, the CO2 isn't going to kill you. The reason for venting is you want to encourage aerobic bacteria which need oxygen. It isn't producing CO2 in large enough quantities to be a concern.

You're prob'ly right. However CO2 is heavier than air and can lay like a blanket on the surface of liquid or solid organic material if not vented out, "suffocating" it, which causes it to turn anaerobic.

[Minggat]

Originally Posted by peghall

You're prob'ly right. However CO2 is heavier than air and can lay like a blanket on the surface of liquid or solid organic material if not vented out, "suffocating" it, which causes it to turn anaerobic.

Am I the only one who has ever inadvertently had gasoline fumes or propane gas get released into the cabin over the years? The blanket that theoretically should have accumulated should have .......... at least suffocated me by now, if not much worse.

Many more than just one poster does not vent the humidity beyond what happens to dishes drying in the rack.

Because I am one that does not vent, I can only speculate that those that do, committed to venting out of fear of failure. Believe me, I had the same concerns. I look back now and think about how I was driving myself crazy with the most simple questions.

Nobody wants to deal with conventional sewage issues. Again, I would say, believe me. We are talking about such a different animal.

I apologize to the OP for not really having higher lattitude experience. But when I was asking myself the question to vent or not, I considered simply setting up the vent to the boats interior at first, rather than committing a deck fitting.

When I discovered that the lid (C Head) was helping to trap A LOT of humidity in the solids bin, and it STILL DID NOt CAUSE AN ODOR ISSUE, I figured I was safe.

So let me suggest that you simply vent the humidity into the cabin, as a aid to the drying process. I will be happy to sell you the tiny little muffin fan that I never installed.

If you find that it isn't needed, you might position it over your dish rack to help the drying process there. Deprive the cockroaches of their most convenient source of water.

[Juho]

Isolated composters can work fine outside even during Finnish winter (temperatures mostly below freezing point). Many people use them to take care of all the organic material that their kitchen produces. Composting heads may have less isolation and the bacteria may have less material to work on, but I still assume they do produce some heat themselves and therefore the temperature of the compost is somewhat higher than that of the surrounding space.

BIOLAN - COMPOSTERS

[peghall]

Most desicators (Airhead, Natures Head etc) and composters do have heaters with fans, so although bacterial activity may be very sluggish, there is some as long as temps remain above 40F. There's no odor when bacterial activity is too sluggish for much if any aerobic OR anaerobic breakdown of the material.

[Simply Sailing]

Originally Posted by peghall

Most desicators (Airhead, Natures Head etc) and composters do have heaters with fans.

Really? We have an AirHead and it did not come with, nor do I believe it is ever sold with, a heater. Where did you hear that they have heaters??? The lack of a heater is exactly what makes AirHead, Nature's Head, etc. DIFFERENT from previous models.

[valhalla360]

Originally Posted by peghall

Most desicators (Airhead, Natures Head etc) and composters do have heaters with fans, so although bacterial activity may be very sluggish, there is some as long as temps remain above 40F. There's no odor when bacterial activity is too sluggish for much if any aerobic OR anaerobic breakdown of the material.

We looked at the major brands before buying ours. None had heaters included and none offered heaters as an option. Even looked at some non-marine units designed for cabins and they didn't have heaters either.

Even when chilled anaerobic breakdown will leave a plentiful stink. It takes minute quantities to be very noticeable. Aerobic is the key to eliminating the stink.

[DainyRays]

I don't completely understand the concern here. We have an AirHead composting toilet that we used all winter long (in Maryland) while living aboard. The air for the head comes from the warm cabin and is drawn outside using the little 12-volt fan. So, the toilet is always at cabin temperature--not the outside temperature.

No "composting toilet" on a boat is ever allowed to truly compost--there isn't enough time before it is emptied. Their true function is dessicating (removing moisture)--not really composting.

Composting toilets should be vented to the outside--not inside the boat. I think there would be an odor if vented inside the boat. Some people have claimed that they can smell a slight odor (on other boats with composting toilets) from the vent outside but I have never been able to detect it on my boat.

Bob


Sent from my iPad using Cruisers Sailing Forum

[Minggat]

Originally Posted by DainyRays

Composting toilets should be vented to the outside--not inside the boat. I think there would be an odor if vented inside the boat.

Simply not true.


No odor.

As has been repeated here many times in different ways, the vent is not for odor control. It's purpose is for the movement of air that contains the moisture that has evaporated out of the solids.

Where some units have trap doors over the solid bins, it is easy to see that the moist air will be more contained, thus a vent to aid in the drying process might be a plus.

The question of odor just does not seem to go away here.

Don't think sewage. If you want to cling to the idea of conventional sewage, then you might have a hard time understanding that there is no sewage odor as well.

Not sure how Webster defines sewage, but my definition is, it's not sewage unless you ADD water to it.