Composting toilets have been around for generations in one form or another. Scandinavian countries first made these toilets commercially viable during the 1960s. With dozens of manufacturers and a range of features available, it can be difficult to determine the right type of composting toilet for your needs. Issues that should be addressed when comparing composting toilets include an understanding of the two main types, their functionality, maintenance, location issues and costs.
There are two general types of composting toilets: self-contained and remote. Self-contained toilets have the composting bin near or under the seat of the toilet. Remote units use pipe to move human waste to another location where the compost bin is located. Each type can be either passive or active. Passive composting means that natural decomposition occurs over time, while active composting uses fans, pumps and mixers to speed up the process. Self-contained composting toilets are smaller and less expensive. Remote toilets resemble conventional toilets.
Both types of composting toilets have similar functionality. There is no odor or wasted material from the compost. Toilets using active composting require electricity to function, while passive toilets can be used without any modern utility. Self-contained units are a more viable option for small homes or for use by fewer than three people on a daily basis. Remote units, also called split models, are more suitable for residences with many people or heavy daily use.
Monitoring and maintenance are important in the use of composting toilets. Of the two main types, remote models are easier to maintain because the toilets themselves are free of the composting process. Comparison of passive and active composting shows that passive methods are easier to monitor and maintain, because there are no moving parts to clean or watch over.
One considerable advantage remote composting toilets have over self-contained units is versatility in location. Self-contained units require access to the composting unit from the rear; therefore, having the toilet located against an exterior wall is almost essential to the operation of the unit. Remote models use a piping system to a central composting unit or "reactor." While the reactor must use an exterior wall for disposal, the toilets themselves can be placed against any wall as long as there is a system in place to deliver the waste to the reactor.
Self-contained units require frequent monitoring compared to remote models, because they fill up faster. Self-contained units also require more cleaning because of their small size. Remote models cost more and require more complex installation. Remote models also use additional plumbing, possibly requiring a professional to install the pipes. While self-contained units have a location issue, remote units take up more space.