composting toilets

What is and How Does A Composting Toilet Work? Ultimate Review

With the world becoming more aware of environmental issues, more and more people are turning to composting toilets for waste management. Have you ever thought about how does a composting toilet works? If so, we have provided a valuable resource for you here, including some outstanding composting toilets on the market.

What Is a Composting Toilet?

A compost toilet is a kind of dry composting toilet since most composting toilets don’t use water for flushing. Composting toilets treat excrement and urine through a biological process known as composting. 

This particular process leads to the decomposition of organic material and makes human waste into compost-like material. The composting process is carried with the help of microorganisms, primarily fungi and bacteria under a controlled aerobic environment.

In various compost toilet designs, a carbon additive like peat moss, coconut coir, or sawdust is added after each use. By doing so, it creates air pockets in the toilet waste to encourage aerobic decomposition. 

composting toilet

This also improves the carbon-to-nitrogen ratio and lowers the chances of unpleasant odor. Many composting toilet systems depend on mesophilic composting, which is an aerobic bacteria-driven decomposition of organic matter at low temperatures.

A composting toilet produces a humus-like end product that can be utilized to fertilize soil if local regulations permit it. Some composting toilets feature a urine diverter in the toilet bowl to gather the urine separately and regulate excess moisture. There’s a type of composting toilet called vermifilter toilet that has flushing water where earthworms are utilized to encourage decomposition to compost.

A composting toilet doesn’t need a connection to sewer systems or septic tanks compared to flush toilets. Composting toilets are normally used for rural areas, off-grid homes, ecotourism resorts, remote holiday cottages, and national parks in developing countries.

Where Does the Liquid Go In a Compost Toilet?

Some compost toilets are incorporated with urine vaults for the collection of urine.

These vaults produce plenty of leachates, and they must be managed carefully to prevent the spread of pathogens. Leachate refers to the extra liquid produced in composting toilets that store urine. It typically accumulates from water in the cells of microorganisms, water from the flushing of the toilet, and urine. 

This liquid normally goes down the composting mass using gravity. As it goes down, it picks up particles and materials that disintegrate before it finally reaches the bottom of the composter. Because of this, the leachate may contain fecal microorganisms/pathogens.

The handling, treatment, and discharge of the excess leachate have to be thought of right from the design stage of the composting toilet to make enough preparations.

Do You Flush a Compost Toilet?

When it comes to composting toilets, there’s no need for flushing with water to get rid of human waste into the septic system. It helps to convert your waste into compost for soil use. This is the reason why a composting toilet is an ideal alternative sewage treatment device. 

Nowadays, composting toilets are well-known as tankless or waterless toilet since it doesn’t need a septic tank or water. Instead, aerobic bacteria come into role to help break down the excrement into compost. But you need to create an ideal environment for the beneficial microorganisms so that they break down the waste.

How Often Do You Need to Empty a Composting Toilet?

How often you need to empty a composting toilet depends on the number of users who use it as a regular toilet. It also depends on the usage and performance criteria of the restroom in your RV composting toilet or house.

But basically, a commercial composting toilet must be emptied every after three months.

The reason is because, by around this point, the compost chamber is typically full of human waste. Because there’s a heating element incorporated into the composting toilet, some amount of urine evaporates, leaving you with a pretty damp content for the composting process.

If you can’t divert the composter’s urine, it will blend with water and solid waste to produce a stench. Due to this, heat is required in the composting evaporation chamber to handle the vaporization of urine through a vent hose. This creates space for more waste.

Can You Urinate in a Composting Toilet?

If your composting toilet only has one chamber, you can certainly urinate in the toilet. It won’t really impact the decomposition process that much.

The only thing that might happen is that the decomposition process can slow down due to too much saturation. To prevent this, you can add extra wood chips or peat moss to help soak up the excess moisture. 

As for composting toilets that have two separate chambers (i.e. one is for urine and one is for feces), you can urinate in the toilet without any problem. The reason is because the toilet diverts the urine into its designated chamber.

However, having two separate chambers means that you need to clean the composting toilet a bit more frequently, particularly the liquid tank that stores the urine. This is due to the fact that with feces, most of the organic matter gets decomposed by the bacteria, and this doesn’t happen with the liquid waste. You need to manually dump the urine diverting toilet tank more regularly.

What Does a Composting Toilet Look Like?

Composting toilets come in two different designs. The first one is the self-contained composting toilets, and the second one is the central or remote composting toilets.

what does a composting toilet look like
Photo Credit: Christopher Porter

Self contained composting toilets facilitate the whole composting system, normally beneath the bowl itself. These types of compost toilets are typically found in tiny homes, boats, or RVs though some are installed in cabins or similar country homes for temporary use. Self-contained toilets normally have to be emptied by hands.

Meanwhile, the central or remote composting toilets direct solid and sometimes liquid waste to a remote composter found somewhere else on the house. They are like septic tanks or compost piles. Larger systems can connect several toilets, which make them perfect for compounds or large homes.

How Does a Composting Toilet Work?

Regardless if a compost toilet utilizes a central or self-contained system, it still requires to establish the proper environment for the aerobic organisms to break down the waste. Doing this needs the right temperature, carbon-nitrogen balance, and moisture level. If these proper conditions are not achieved, then you might be greeted with an unpleasant smile or sight when you inspect or empty your compost.

Too much moisture in your composting toilet can drown aerobic bacteria, so what you want to do is keep the toilet moist but not completely damp. This is also the reason why most composting toilets are incorporated with a separate urine container for liquid waste that needs to be emptied once it fills. 

Some options for this, at least when it comes to self-contained units, include a drain pit. Certain units even include methods to evaporate the liquid.

Properly disposing of urine in the right way also aids remove extra nitrogen buildup in the compost pile. But adding carbon-rich materials like coconut fiber or peat to the pile will guarantee the correct nitrogen-carbon balance.

Lastly, aerobic microorganisms thrive at a temperature of between 60 and 100 degrees Fahrenheit. Some brands include additional contrivances, automatic mixers, sensors, or thermostats in order to maintain the right moisture control, chemical balance, and temperature.

Does a Composting Toilet Smell?

For some people, yes. For others, no. It is important to note that the smell of composting toilets depends on what material you are using for your toilet and how often you empty the composting chamber.

Types of Composting Toilets

There are various kinds of composting toilets, and each one of them has its own unique function. But the dry compost that they produce doesn’t really differ that much. Here are the types of composting toilets you should be aware of.

Slow Composting Toilet

Slow composting toilets or also known as “cold composting toilets,” allow the compost to pile up slowly before they are taken out of the storage. Compared to other types, the end-products/compost from this type of composting toilet might still contain pathogens that can be harmful to plants and human health.

In a slow composting toilet, all the waste you drop into the toilet is separated from the main component. You can close it after each use for a better decomposition process. Most of the time, you might need to utilize the vermicomposting process by adding some red wriggler worms to improve the composting process.

Unlike regular flushing toilets, slow composting toilets consume more time to reduce the pathogen and decompose the excreta in the waste. 

Fact: Slow composting toilets are primarily meant in remote trail areas and for seasonal use. 

Active Composters

An active composter system, or also called as “self-contained” toilets is incorporated with a chamber attached to the toilet. Compared to conventional toilets, they are larger in size.

Depending on the manufacturers or models, some active composers feature heating elements and aeration fans. These features aid in maintaining the oxygen and temperature to the needed optimum level all the time.

Most users of active composters normally apply a small amount of absorbent carbon material, also known as “bulking agent.” This material helps in absorbing the waste moisture and speed up the aerobic composting process.

Vermicomposting Flushing Toilet

Vermicomposting flushing toilets utilize earthworms to speed up the decomposition of the waste into compost. This type of composting toilet features a filter bed that stores all solid waste while the liquid goes through a filter screen and is then removed by a reactor.

The aerobic microorganisms and composting earthworms present then start the decomposition process of the solid waste such as toilet paper and feces. Then it converts them into stable organic compounds.

Compared to other types of composting toilets, this one utilizes water to flush off the waste deposited in it. The good thing is that you can link it to any micro-flush toilet or low-flush tank.

Components of a Composting Toilet

If you’re planning to get a composting toilet, you should know first its component. As we’ve already mentioned, a composting toilet utilizes a natural process to break down the waste into compost. But there are certain components that are behind this process.

When it comes to composting toilet systems, the two most vital components are the toilet seat section and the collection unit.

The seating section lets you position and answer the call of nature comfortably.

Meanwhile, the collection unit is what differentiates it from traditional toilets installed in most houses. This major component of the toilet is where the collecting and breakdown of waste take place.

There are two primary sections of the collection unit, which include:

Composting Chamber

This section plays a very important role in the toilet. First, it acts as a storage section where all the human waste is deposited and decomposed.

Additionally, a composting chamber is where the urine and excrement convert into useful compost material. Most manufacturers use a slope-shape design in the chamber to easily separate the urine and solid waste.

Aeration Unit

In order for a composting toilet to perform at its best consistently, smelly gases need to go out naturally. And this is where the aeration unit plays a role. It is engineered to help maintain the necessary level of temperature, aeration, and oxygen. The aeration unit is essential as it allows a better decomposition process consistently.

Benefits of Using Composting Toilet System

Here are several benefits of having a composting toilet system

Installation is Easy

A composting toilet can be installed pretty much anywhere. They are easy to install and are especially popular in remote places or locations that don’t need permanent residence.

No Need for Water Use

Modern composting toilets work just like convetional toilets. The only main difference is that they don’t need a water source except for the vermicomposting flushing toilet type. Because they don’t require water for flushing, you’ll be able to save up on water. That’s why they are perfect to use in rural places or in areas where a reliable water source is not available. They are also ideal in areas where there are high septic demands or low water pressure.

Installation is Cheap

As we’ve already mentioned above, most types of composting toilets don’t need to use water or a connection to a sewer or septic system. Due to this, they have lesser installation needs, are easy to install, and have an inexpensive price range. In fact, most composting toilets out there go for less than a thousand grand and cost less to install.

Final Product Can be Utilized to Enrich Soil

The finished compost are beneficial to the soil as they add essential nutrients such as calcium, nitrogen, phosphorous, and potassium. It works as manure or organic fertilizer that can be utilized to enrich the soil. Aside from that, you won’t need to buy inorganic fertilizers. In residential areas, the end products can be utilized for general gardening like flowers, trees, or other plants.

Space-Saving Toilet

A composting toilet doesn’t need a water source, and thus, it can be installed practically anywhere. They are ideal for areas where size is limited and can even be installed outside.

Minimal Maintenance Needed

Some toilet models might need you to add water or mix up the compost. Unlike these models, composting toilets only need an installation, and you’re good to go. Most composting toilet types eliminate urine and water, leaving only the solid matter to decompose by itself.

What is the Cost of a Composting Toilet?

The cost of a composting toilet varies depending on the type you choose and how advanced it is. The self-contained unit starts at around $600, while more advanced central systems can run into thousands of dollars.

The Nature Head Compost toilet is a composting toilet that can be installed anywhere for less than $1000. For its price, it has some of the best features in place by including advanced oxidation technology and self-cleaning capabilities.

It allows you to use your own materials with no need for special compost or water treatment chemicals because it uses nature as its filter system so you don’t have to worry about anything except deciding where to install this great device!

Two of the Best Composting Toilet Designs

Here is a look at two great examples of composting toilets you can purchase for yourself. They are well built and incredibly reliable.

Natures Head Composting Toilet

natures head composting toilet
803 Reviews
Nature's Head Self Contained Composting Toilet
The Nature's Head Self Contained Composting Toilet is among the favorites. It is simple to use and easy to install. This toilet has made a name for itself with its odor-free operation and low maintenance needs. It was originally intended for marine uses, but it is now frequently installed in tiny houses, outhouses, cabins, RVs, and many more. This toilet has two versions. The first one comes with a more conventional crank model. The second one is equipped with a spider handle. The latter is more popular because of its space-saving design. It is incorporated with a pretty good storage capacity for solid waste, about 60 to 80 uses. Its liquid container must be emptied regularly for best performance. Most people new to composting toilets choose the Nature's Head Composting Toilet because it is among the most popular, if not the most. Also, many users are amazed by its effective odor management. Plus, it is wired for 12V power to keep the exhaust fan working. However, some users found it necessary to upgrade the unit to a more powerful one. But it's still up to you.

Separett Villa 9215 AC/DC

separett Villa composting toilet
273 Reviews
Separett Villa 9215 AC/DC
This composting toilet features a simple and compact design. It provides great comfort for users. It is ideal for both off-grid and on-grid living. You can use it in your home with ease. Additionally, you can even install it in your boat or as a RV toilet or portable toilet. You can easily power its single-speed electric fan with AC or DC supply. Its fan helps evaporate the liquid and keep the solid waste dry for optimal performance. Furthermore, the Separett Villa 9215 AC/DC comes with a pressure-sensitive seat. Its solid bin opens automatically as soon as it senses someone sitting on it. You won't have any odor problems with this composting toilet as it comes with separate containers for liquids and solids. Just be sure that you cover the lid to decompose the waste faster and effectively. It also features a composting bag which is removable. Its composting process happens in the bag, not inside the toilet. Also, it comes with an ETL Certification as it t meets all the regulations and standards of the certification program. Lastly, the materials used to design this toilet are high-quality, so rest assured that you'll get the most value for your hard-earned money.

Last update on 2022-10-30 / Affiliate links / Images from Amazon Product Advertising API