Composting toilets use no water and are kind to the environment. With our tips you can build a composting toilet yourself or learn more about it.
The composting toilet - how gladly is it dismissed as a crude idea of the eco-movement and just accepted as a vacation or small garden alternative. But hardly anyone knows that the composting toilet developed parallel to the water closet in the 19th century. Modern composting toilets are also hygienic and can look just as attractive as a water closet. The following article deals with the structure, function and benefits of composting toilets, we also give you a quick guide on how to build it yourself and introduce some manufacturers.
Composting toilet: what is it?
The composting toilet - also known as a dry toilet or hummus toilet - is usually operated entirely without water. The goal is always to return human legacies to the nutrient cycle, because they contain valuable plant nutrients that can be used as fertilizer and are compostable. This is where humus toilets differ from the chemical toilet or the downstairs toilet, because in these models human feces are disposed of unused. The idea of the composting toilet makes a lot of ecological and economic sense: Instead of first contaminating our water cycle with feces and then cleaning it up in sewage treatment plants, the nutrient and water cycles could remain separate at all times with the help of composting toilets. In addition, the time-consuming - and in some locations impossible - connection to the sewage system is no longer necessary. For this very reason, composting toilets have been used in Scandinavia for decades at rocky, lonely locations close to water.
Tip: The history of the composting toilet already includes several chapters: The British pastor Henry Moule invented and patented the so-called earthen toilet as early as 1860, in the Victorian era. For a long time, urine-diverting toilets were also used in many German cities - the urine was drained out where it met a so-called clay wall. This absorbed the liquid and remained after the water had evaporatedcrystallized nitrate of lime (calcium nitrate). This was regularly removed from the so-called nitrate and sold profitably to fertilizer manufacturers or ammunition manufacturers - because converted to potassium nitrate it was used to produce black powder. Here you will find a video presenting the work of the s altpeters.
Summary: What is a composting toilet?
- A composting toilet operates without water, which is why it is also called a dry toilet
- Water and nutrient cycles should remain separate from the outset
- The excrement is then not disposed of, but used
- The reason for use can be an ecological requirement, a lack of connection to the sewage system or the desire to save water
Composting toilet: structure and function
Composting toilets are divided into two distinct categories - the "collective" and the "dry-separating" toilets. Of course, like any toilet, they have a seat, a seat and a lid. Unlike toilets, they also have an exhaust air system. This ensures good ventilation of the compost material and a suction effect - similar to the chimney of a chimney - for good air in the compost toilet. The use of so-called structural material is also important in any case. Bark mulch, straw or wood chips - natural materials with a wide C/N ratio, i.e. a wide ratio of carbon to nitrogen - are intended to absorb excess liquid, loosen the compost and provide a carbon source for the composting microorganisms. If you want to revisit exactly what the C/N ratio and carbon are all about, we can recommend this special article on humus management.
The conventional composting toilet or "collective toilet"
In this model, solid and liquid are not separated from the outset, but collected together in one container. Depending on the design, the process then continues differently:
- The container is filled with solids and liquids and then emptied - this is often solved by removing a compostable bag. Everything together can then be composted in a composter.
- There is a composter under the toilet seat to compost solid feces. Liquid seeps down, is dumped out and into the sewer, or is highly diluted and used as liquid fertilizer. The composter is about theRemoval flap gradually emptied, fresh and finished compost can be removed.
- Solid and liquid are fed into a combination tank. Both are then kept separately until they are finally emptied.
The composting toilet with urine separation or "dry composting toilet" (TTC):
With the dry separating toilet, urine and excrement are collected separately from the start. The urine is either discharged into the sewage system or collected in a canister and used as a liquid fertilizer in a highly diluted form. The solid components, on the other hand, are either composted directly in a container located under the dry composting toilet or collected dry and taken to the composter on a regular basis. A flap can block the view from above into the composter.
How to use a composting toilet?
You can probably guess how a composting toilet is used. But running a composting toilet also includes other aspects:
- Spreading with bark mulch, bark chips or wood shavings
- Perhaps rinsing the urine separator clean with a little water
- Emptying the urine canister at regular intervals (on most models) - depending on the volume of the canister and the number of users
- Removal of the solid part - either for composting or as finished compost - depending on the model
Tip: It is actually absurd to dispose of the urine completely unused. Since this contains large amounts of nitrogen and other plant nutrients, it is suitable as a fertilizer. You can read more about the pros and cons of urine fertilization here.
Composting toilet in the house, on the boat, at the campsite?
Composting toilets can be used in many ways. We have compiled the various places for the special quiet place for you below.
Composting toilet in the house
If you want to install a composting toilet in your home, you can use a dry composting toilet. Because a toilet with directly connected composting would mean that a large-volume composter would have to be permanently installed in the house and under the toilet. Since a toilet in the house should also fit into the design of the bathroom, self-construction is the norm. Here, kits are used that form the functional core of theform toilet. The scope of such a set can vary. All around you can then design the toilet according to your own wishes. You can read more about building a composting toilet at your permanent residence and the kits used here.
Composting toilet in the mobile home
A composting toilet can also be operated in a mobile home or on board a ship. Again, the dry composting toilet is recommended, because when separating the urine, the emptying interval is significantly longer. Also, unpleasant odors only develop when urine and excrement come together. If a trip lasts longer than three weeks or if there are more people on board, the sack with the dry excrement can be disposed of in the residual or organic waste. If one cannot be found either, the sack can be buried in extreme emergencies so that nature can take care of the recycling. Liquid must be collected and disposed of on occasion.
Composting toilet in the allotment garden and at the summer house
If the installation of the toilet in a separate toilet building is planned, the composting can be connected directly to a collective toilet. To do this, the toilet must be high enough so that there is enough space for a composter underneath. However, such dimensioning is usually not necessary at all. Small to medium sized combo models are available for purchase and only need to be installed in an existing cottage.
Legal requirements for the composting toilet
The operation of composting toilets in Germany moves in legal gray areas in many areas. While there are no legal problems with using your own garden in a private ornamental garden, there are no suitable specifications for communal gardens - for example in apartment buildings. The spreading of human excrement is prohibited on areas used for commercial gardening or agriculture. However, if they have been composted at a recycling center, they are converted into hygienic compost and can be used.
After all, pathogens that are dangerous for humans can be found in our legacies. If they are to be used on areas that serve to produce food, they must first be "sanitized". Sanitization through composting or pasteurization can be used for this. According to the World He alth Organization (WHO), the former should last at least two years, the latter cancomplete within about two hours in a suitably sized oven.
It can also be important whether a planning application has to be submitted for the construction of a free-standing, stationary composting toilet. You should definitely clarify this before construction. Incidentally, the necessary composting plants in Germany do not require a permit for a daily throughput of up to ten tons.
Build your own composting toilet
Depending on where you want to set up a composting toilet, the models presented above are better or worse. Basically, a higher level of comfort or aesthetic demands always requires you to do your own work, because almost all finished composting toilets are made entirely of plastic and have a more functional design. If you are thinking of building your own composting toilet, we recommend using kits for the basic elements. In the next section you will find an overview of the individual steps you can follow when building your own compost bin. In this case, we assume the use of a separate privy model. The result is a dry composting toilet. Please note, however, that a wall opening is required to install an exhaust air pipe. Very small toilets, on the other hand, can do without ventilation.
How to build a composting toilet yourself
What you need:
- Separett Privy kit (e.g. Separett Privy 500)
- A bucket for solids, a canister with a lid for liquids
- Building materials and tools for base cabinet and top plate. In these instructions, we assume a wooden substructure. Of course, other building materials are also possible
- Pipe with a diameter of at least 75 mm for installing the exhaust air, which must lead out of the room to the outside. Possibly bends, seals and pipe lubricants to make this happen
- You will need a composter or at least an organic or residual waste bin by the time you empty it for the first time
We have compiled the various work steps for you below:
- In the beginning there is the construction of a base cabinet, in which the two collection containers for solids and liquids will later have space. Build at a height that allows you to sit comfortably. Beveled or round designs can also increase seating comfort. At very highCollecting containers may require a raised step to put your feet down. It is also important to install a lockable door, behind which the containers and other toilet utensils can be hidden.
- Then the toilet seat is inserted into the cover plate of the base cabinet. To do this, simply saw in a suitable lock and then insert the seat - if possible using foam sealing tape. Also note the subsequent seating position here: Especially for smaller users, the seat should be as far forward as possible on the edge. Seal the seat all around with silicone.
- The next step is to install the exhaust air pipe. For this purpose, a suitable hole is also sawn in the cover plate or the rear wall, the tube is inserted up to the position of the collection container and fixed. The exhaust air pipe is now extended to the wall opening with bends and other pipes. Outside it must be covered with a rain cover. The pipe is fixed with clamps and sealed at the entrance to the base cabinet. Of course, you should also make the wall opening tight and insulated. Insulating the entire exhaust duct can involve hiding it behind a shroud and preventing the duct from cooling the entire room with outside air.
- Now position the solids container under the toilet seat. This is lined with a compostable bag. The tubing of the urine separator must be placed in a canister. Here, too, you should make sure that there are no leaks: It is best to insert the hose through a hole in the lid. Incidentally, a second lid without a hole can be very useful for transporting the canister.
- Now your composting toilet is almost ready to use. We recommend that you oil or paint the substructure to make it water-resistant, to make regular cleaning easier. Of course, you also need a container for structure material and a small shovel or trowel for sprinkling.
Rental composting toilet
Are you planning an event and need toilets? In addition to the Dixie, you also have the option of renting composting toilets.
Ecotoilet has several models to offer: from very small to very large and comfortable. In any case, the large models no longer look at all like hippie or eco-movements and offer everything you need for a “pleasant defecation”.
Ökolocus GmbH also offers long-term rental of a locomotive, with almost no limits to the installation site: thanks to the modular principle, you can toothe most hidden corners serve as "little places".
Kompotoi is an all-rounder when it comes to composting toilets: They not only offer mobile toilets, but also the entire planning and implementation of individual, stationary composting toilets in single or multi-family houses, alpine huts or holiday homes.
In addition to these three providers, there are many others who will be happy to provide your summer party, camp or wedding with sustainable and fragrant toilets.
Dispose of compost from composting toilet
As mentioned in the legal section, it is safe to use composted manure in the ornamental garden. If you still need tips for correct composting, you will find them here. However, two years of composting or two hours of pasteurization at 70 °C is required before it can be used in the kitchen garden. You can apply diluted urine or drain it into the sewage system.
If you don't want to use your own legacies yourself, you can also dispose of them in the compost bin. Your ecological advantage is then still enormous and the further processing at the recycling center closes the nutrient cycle. Incidentally, the hot gang guarantees complete sanitation, so that the transmission of diseases is ruled out. Perhaps on a future stroll through the market you will come across vegetables that have been grown using the compost from your manure.
Have you heard of the Bokashi compost trend? We introduce you to the space-saving alternative to the compost heap.