Have you ever wondered how a self contained composting toilet actually works? Well, this is the article for you. In this article we outline all the different parts of a self contained toilet and how they all work together to make usable compost from human waste.
Self contained toilets are different to split systems in that they are one complete stand alone unit. Split systems have two main components to them – the pedestal and the chamber. Self contained units are all-in-one so are perfect for houses built on concrete slabs or homes where underfloor space isn’t available (like tiny homes or boats / mobile homes).
Now that we know what a self contained composting toilet is, it’s worth breaking down the different models of toilets into categories so we can better understand the differences.
Manual Composting Toilets
A manual composting toilet typically has a handle that needs to be turned or cranked to mix the waste to help promote the composting process. Many manual composting toilets are what’s called batch processing toilets. This means that you have a series of buckets or trays and the compost is collected in batches (unlike larger models where more compost is held so buckets don’t have to be interchanged).
With these type of manual, batch process type toilets, there is a little more maintenance to be done than a fully automatic model in that you will need to interchange buckets or trays (depending on your model) to let your compost cure, and remember to turn and churn the waste to help with the composting process.
Semi-Automatic Composting Toilets
Semi-automatic composting toilets typically have some element to them that takes the manual nature out of maintenance. This could be a variety of different things ranging from an automatic mixing arm to heating elements and exhaust fans.
This can differ depending on the model and accessories you add to your system.
Fully Automatic Composting Toilets
As the name suggests these are fully automated systems where input into the everyday workings of the system are minimal. Usually, these types of systems will incorporate an automated mixing element (usually mixes when the lid is opened or closed), a heating element and an exhaust fan.
Less maintenance = more power
As you can see from the outlines above the more a composting toilet is automated, the more power it will require to run mixing arms, Biodrums heating elements and exhaust fans so you will need to take this into consideration when thinking about the best composting toilet model for your circumstances and the type of power you have access to (mains, solar, wind or a combination, etc).
OK, but how does a self-contained composting toilet work?
Alright, now that we’ve gone through the process of describing the different types of composting toilets, we can get into how they actually work. Here’s how the system would work from a person's point of view:-
- Open the lid of your toilet (depending on your model the mixing arm will activate)
- If there is a chamber screen this will open
- Do your thang
- When you close the lid this will close the chamber screen and activate mixing arm or Biodrum (depending on the model)
- Depending on your model, roughly 1-2 times a month you will need to empty bio-bags or change trays or drums (this varies greatly on usage and model)
If you’re more interested in the actual composting process, we suggest you head on over to the article What actually happens when you poop in a composting toilet? as this article goes into great detail about the different stages of composting human waste and how it works from a biological viewpoint.