Self-Contained composting Toilets: A New Necessity?

Self-contained toilets: A new Necessity?
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Many people will have heard of compost toilets as a method of greener living. However, you may not know that composting toilets are classified into two types: self-contained and central composting toilets.

Both, however, have the same goal: to kill germs and recycle our urine and human waste without requiring water. Instead of flushing, the waste is sent through a pipe to a composter, which is concealed from view by a trap door or screen.

They don’t appear to be all that different from your conventional toilet. Composting, self-contained toilets are typically seen in cottages or for summer residential use. If more than two individuals are utilizing the unit, it should not be operated all year.

As the name indicates, the toilet and composter are integrated in one unit, so composting occurs just beneath your toilet seat.

However, there’s still al lot to evaluate when it comes down to a self contained composting toilet. In this article, we will go through the ins and outs of a self contained compost toilet in comparison to the central system.

How does a self-contained composting toilet work?

For a long time, the only toilets that many people knew about were those with an external waste tank. These are known as “wet-flush” systems. They have a number of disadvantages, but they are still the most common type of toilet in use today.

In the United States, self-contained toilets are not yet a necessity. But for other parts of the world, they provide an affordable and sustainable solution to sanitation needs. In fact, more than 1 billion people worldwide live in places where there is no toilet at all! Self-contained composting toilets have been used in many developing countries since 2005 as a means to address this problem without breaking the bank.

Self-contained toilets differentiate from central systems in that they are a single, self-contained unit. Central systems are made up of two major parts: the pedestal and the chamber.

Because self-contained composting toilet units are all-in-one, they are ideal for traditional houses which are built on concrete slabs or dwellings with no underfloor room, or boats.

Central composting toilets- how do they differ?

These toilets are typically put in homes that have space beneath them. The composting chamber is located beneath the home, the pedestal is located above it in the bathroom, and the chute links these two components.

The chamber with a centralized system is generally a full level beneath the toilet itself.

Centralized composting toilet systems offer more capacity, are usually more costly, and are most commonly utilized in office or commercial buildings. 

However, once installed, they require less frequent care and only need to be emptied roughly once a year. AlasCan, Clivus Multrum, CTS, EcoTech Carousel, Phoenix, and Sun-Mar Centrex are popular systems, with costs ranging from $1,400 to more than $10,000 depending on the system’s capacity and intricacy.

There are both electric and non-electric options available for central composting toilets.

This makes it a more costly composting process, yet a convenient and easily maintained option.

Below are some Central composting toilet systems along with their prices, tools, and features.

Extra – High Capacity
Sun Mar Centrex 3000 Composting Toilet – AC – Internal Composting – Split
9/10 Our Score


The Sun Mar Centrex 3000 composting self-contained toilets can accommodate 6 adults or a family of 8 on a regular basis at home, or 9 adults or a family of 11 on weekends and holidays.

The Sun Mar Centrex 3000 Air Flow composting toilet system is designed for medium household use with a continuous compost flow. The rotation of the Bio-Drum in a continuous flow system pushes compost along the drum before it drops automatically into the collecting container (50 liter) at the end of the unit.

The Sun Mar Centrex 3000 is the only one with this functionality. The drum will not have to be rotated anticlockwise for emptying under typical working circumstances.


  • Price: $4,278 inc. VAT
  • 6-8 Residential/Continuous Use
  • 9-11 Weekend and Vacation Use
Continuous Flow System
Sun Mar Centrex 3000
8.9/10 Our Score


The CENTREX 3000 is a one-of-a-kind Sun-Mar Central unit.

It has a continuous flow design and is intended for heavy cottage or medium household use. The rotation of the drum in a continuous flow system pushes compost down the bigger and longer CENTREX 3000 drum before it drops automatically into the collecting container at the end of the unit.

The drum will not have to be rotated for emptying under typical working circumstances.

It has high capacity and volume, suitable for up to 11 people to use.


  • Weight: 144 lbs
  • Dimensions (L x W x H): 62 × 30 × 34 in
  • Built-in heating element and fan assembly

Benefits of self-contained toilets

Nowadays, self-contained toilets offer homeowners and businesses not only environmental benefits, but also convenience and cost savings too!

  • they are more environmentally friendly
  • require less water usage
  • can enhance the growth of non-edible plants in locations where soil amendment is permitted
  • they are well suited to remote areas.

Models of self-contained composting toilet

Many brands manufacture and produce such composting toilet models, such as Nature’s head, Sun Mar and Separett. So it’s safe to say you have a wide enough choice that you could buy one even with a low budget.

Below is a list of self-contained toilets with composting system, products that you can add to your list of purchases and compare and contrast to each other.

High Capacity
Sun-Mar Excel Self-Contained Composting Toilet, Model Excel 
9.2/10 Our Score


The Sun-Mar Excel composting toilet processes toilet waste into safe fertilizing soil while remaining odorless.

This model is designed for high capacity use, ideal for a 3-4 person in a residential setting or 6-8 people at a cabin for a weekend.

This model contains Venting Kit and an emergency drain.


  • Vent Stack Size: in. 2
  • Dimensions: L x W x H in. 33 x 22 1/2 x 33,
  • Electric: Yes
  • Self Contained: Yes
  • NSF/ANSI Certified: Yes
  • Pest Proof: Yes
  • Detachable Footrest: Yes

The high capacity composting toilet may be utilized almost anyplace, including homes, cabins, and small business applications.

A low-profile device, it may be used in any bathroom. It does not require any water.

The 100% non-polluting compost-processing bio-drum is powered by your ordinary home current.

For Smaller Spaces
Urine diverting toilet Tiny® with Urine Container
9/10 Our Score


Separett Tiny is a self-contained, urine-diverting composting toilet designed specifically for Tiny Homes and other tiny places such as camper vans, caravans, boats, hunting cabins, and so on.

All that is required for installation is 12 V or 110–240 V electricity and a 50 mm pipe for toilet ventilation.


  • Battery cables for 12 V use
  • Universal adapter for 110-240 V use
  • 1 x latrine container with lid
  • 1 x urine tank
  • Ø 50 mm ventilation pipe 40 cm
  • Adapter Ø 50 mm – 1 ½ ”
  • Ventilation grille with insect net
  • Ventilation cowl
  • Holder for drain cleaning tablet
  • Screws for wall/floor
  • Sample compostable bags
  • Drain cleaning sample
  • Absorb pad sample
  • Filter for ventilation pipes


  • Material: Recyclable high-gloss polypropylene
  • Emptying interval with 4 users (liquids): Every other day
  • Every other day Emptying interval with 4 users (solids): Twice a week

This Tiny model houses both liquid and solid waste inside the toilet, with two containers, one for urine and one for solid waste.

If the toilet is utilized in a two-person household, the solid waste container must be emptied once a week. The urine container must be emptied at least twice a week.

When it is time to empty the urine container, a sensor sends a signal to the Separett-logotype, which lights up in red.

Lightweight and Odorless
Nature's Head Self-Contained Toilets with Close Quarters Spider Handle Design
8.9/10 Our Score


The composting toilet is urine-diverting, and waterless, making it suitable for a wide range of settings. 

The Nature’s Head is lightweight, odorless, and compact, making it ideal for your home, cabin, tiny house, RV, workshop, boat, or survival application.


  • Colour: Granite
  • Product Dimensions: 55.88 x 52.07 x 55.12 cm
  • Weight: 12.7 Kilograms
  • Brand: Nature’s Head
  • Installation type: Floor Mounted
  • Shape: Spider Handle

This product has all stainless hardware with a full-size elongated toilet seat for comfort. It is easy to install and disassemble in seconds for emptying. As a bonus, a Vent hose and fan are already included with the product.

See here for a full review of the Nature’s Head Composting Toilet.


Both self-contained toilets and central toilet systems are an excellent way to switch to composting toilets and fulfill your purpose of sustainable living!

The choice comes down to deciding on your budget and looking at which system would be best for your living and residential space. There are many other types of composting toilets to choose from, such as solar composting toilets and waterless toilets, so be sure to have a look at all your options before making your decision.

ImageProductOur ScoreLearn More
Most Reliable
Sun Mar GTG Portable Toilet
Sun Mar GTG Portable Toilet

Sun Mar has a patent for the most efficient composting method, all while having a long-standing history of creating and producing composting toilets. 

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Best Value
Separett Villa 9215 AC/DC
Separett Villa 9215 AC/DC

Separett has been developing waterless toilet solutions for over 40 years with the goal of improving quality of life and making everyday living easier and more pleasant for everyone.

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Best Overall
Nature's Head Composting Toilet
Nature's Head Composting Toilet

The Nature’s Head composting toilet is one of the most popular models out on the market right now. Tiny house owners absolutely love them, and for good reason too. 

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Best Value
Air Head Composting Toilet
Air Head Composting Toilet

A convenient installation for mobile lifestyles. It eliminates the need for water flushing, is easy to use, has a female-friendly design, and is water efficient, 

Check Latest PriceRead Full Review