How Do Composting Toilets Work in RVs: A Simple Guide to Eco-Friendly Travel

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how do composting toilets work in rvs
How do composting toilets work in RV’s?

Composting toilets have become increasingly popular among RV enthusiasts as a sustainable alternative to traditional flushing toilets. These eco-friendly toilets utilize the natural process of decomposition to break down human waste into a nutrient-rich fertilizer. By separating solid and liquid waste, composting toilets eliminate the need for a cumbersome black water holding tank and reduce the overall waste output in an RV.

In order to function efficiently, RV composting toilets employ a combination of features such as trapdoors, fans, vents, and sometimes heating elements. When the toilet is “flushed,” the waste drops into a lower tank area. Liquids are separated and sent to the front of the tank, while solids are directed to the back. A fan and vent system or heating element aids in evaporating liquids, and a composting medium, such as coconut coir or sawdust, helps to break down solids into compost over time.

Key Takeaways

  • Composting toilets save space and resources in an RV by eliminating the need for a black water tank.
  • These eco-friendly systems separate liquid and solid waste and use natural processes to break down waste into usable compost.
  • Familiarity with the components and maintenance of RV composting toilets is essential for their optimal function and longevity.

Basics of Composting Toilets

Composting toilets are an alternative to traditional RV toilets that offer a more eco-friendly and efficient method of waste management. These toilets use the process of aerobic decomposition to break down human waste, rather than flushing it away with water. With composting toilets for RVs, users can save water and create fertilizer at the same time.

There are two main types of composting toilets for RVs: self-contained and centralized. Self-contained composting toilets have detachable tanks and bins to dispose of liquid and solid waste separately. This design makes it easy to clean and maintain the toilet. Centralized composting toilets connect the toilet to an external composting unit, usually located outside the RV, which collects and processes the waste.

The design of RV composting toilets is focused on managing and separating liquids and solids. Most composting toilets have distinct compartments for solid and liquid waste. Liquids are typically evaporated or diverted into a separate container for disposal. A fan and vent system or a heating element is used to speed up the evaporation process. Solid waste, on the other hand, is mixed with a bulking agent, such as coconut coir or sawdust, to facilitate aerobic decomposition and control odor.

In terms of maintenance, composting toilets for RVs typically require more frequent emptying of the liquid waste container as compared to the solid waste compartment. However, the frequency of emptying depends on the usage and evaporation rate. Properly maintained composting toilets can provide an efficient and odorless waste management solution for RV living.

Overall, RV composting toilets offer a more sustainable and environmentally friendly option compared to traditional RV toilets. By utilizing the natural process of aerobic decomposition, these toilets help conserve water and turn waste into a useful resource. Additionally, they reduce the need for chemicals and the dumping of sewage at dump stations, making them a preferred choice for environmentally conscious RV enthusiasts.

Components of RV Composting Toilets

How do Composting Toilets Work in RV's
Composting Toilets in RV’s are self contained units

Separation of Solids and Liquids

One of the key components of RV composting toilets is the separation of solids and liquids. This is crucial as it aids in preventing unpleasant odors and proper composting. When using the toilet, the solid waste and urine are separated into different chambers. The liquid waste (urine) is typically collected in a removable tank, while the solid waste remains in a separate container to undergo the composting process.

Composting Medium

A composting medium is essential for breaking down the solid waste into a safe and usable fertilizer. This medium is commonly made of peat moss, coconut coir, or sawdust. By mixing the composting medium with the solid waste, it promotes the growth of microorganisms that decompose the waste material. Oxygen is a crucial element for these microorganisms to thrive and break down the waste more efficiently.

Ventilation System

Proper ventilation is an important aspect of RV composting toilets. A well-designed ventilation system provides the necessary oxygen for the composting process and helps to evaporate moisture from the solid waste. It also plays a role in preventing unpleasant odors by venting them outside of the RV. Ventilation systems rely on a pipe that runs from the composting chamber to the exterior of the vehicle to ensure adequate airflow.

Exhaust Fan

An exhaust fan is another essential component of RV composting toilets. Typically connected to a 12-volt system, the fan maintains continuous air circulation within the composting chamber. This helps in both speeding up the composting process and further preventing unwanted odors. Additionally, the exhaust fan contributes to the evaporation of liquid waste, especially in models with heating elements that accelerate evaporation.

Installation and Maintenance

Installation Process

To install a composting toilet in your RV, follow these steps:

  1. Choose a suitable location: Select a spot that is easy to access, has sufficient headroom, and consider the proximity to windows and vents for proper ventilation.
  2. Remove the existing toilet: Disconnect any plumbing, unscrew the bolts attaching the toilet to the floor, and carefully lift the unit off its base.
  3. Prepare the new composting toilet: Assemble the toilet according to the manufacturer’s instructions, and make sure to fill the bottom chamber with the recommended composting material.
  4. Install the vent pipe: Cut a hole in the RV wall or roof, then install the vent pipe and cap using the provided hardware. Make sure it is properly sealed to prevent water intrusion.
  5. Mount the composting toilet: Secure the toilet to the floor using the included brackets and hardware, and ensure the top bin aligns with the lower chamber.
  6. Connect any accessories: If your model includes electric fans or heating elements, connect them according to the manufacturer’s instructions.

Cleaning and Care

Maintaining a composting toilet in your RV requires regular attention:

  • Emptying liquids: Most composting toilets separate liquids from solids, so you will need to regularly empty the liquid container to prevent overflow. Frequency depends on usage, but expect to do this every few days to a week.
  • Emptying solids: When the solid waste container is full (usually after 4-6 weeks for two people), remove it from the RV and dispose of the composted material in an approved location.
  • Add more composting material: After emptying the solid waste container, replenish the bottom chamber with the recommended composting material to keep the process going.
  • Cleaning the toilet: Periodically clean the toilet bowl and exterior with mild, environmentally-friendly cleaning solutions to maintain hygiene and prevent odors.
  • Inspect the vent system: Check the vent pipe and fan (if applicable) regularly to ensure they are functioning properly and clear of debris.

By following these installation and maintenance steps, you can enjoy the benefits of an environmentally-friendly, odor-free composting toilet system in your RV.

Composting Medium Options

When using a composting toilet in your RV, choosing the right composting medium is essential for proper function and odor control. In this section, we will discuss two popular composting medium options: Coconut Coir and Peat Moss.

Coconut Coir

Coconut coir is a natural byproduct derived from the outer husk of coconuts. It is a popular choice for RV composting toilets for several reasons:

  • Sustainability: Coconut coir is an eco-friendly option, as it reduces the amount of waste from coconut processing.
  • Odor Control: Coconut coir is effective at absorbing liquids, helping to control odors in the composting toilet system.
  • High Absorbency: Its high absorbency means that it can hold moisture well, promoting ideal conditions for decomposition.

To use coconut coir in your composting toilet, you’ll need to hydrate the compressed bricks. Afterward, break apart the moistened coir to achieve a loose, fibrous consistency. Evenly distribute the appropriate amount of the prepared coconut coir into your composting toilet’s solid waste chamber.

Peat Moss

Peat moss, particularly sphagnum peat moss, is another popular choice for composting medium in RV toilets. Similar to coconut coir, it offers the following advantages:

  • Natural Source: Peat moss originates from peat bogs, making it an organic and natural composting medium.
  • Moisture Retention: Like coconut coir, peat moss excels at absorbing and retaining moisture, promoting optimal decomposition conditions.

When using peat moss, be sure to choose a product without added chemicals or fertilizers, like peat mix. This ensures a safe and efficient composting process in your RV toilet. To prepare peat moss for use in your RV composting toilet, loosen the compacted material and distribute it evenly into the solid waste chamber.

Note: As peat moss sourcing can sometimes have ecological impacts on peat bogs, it is essential to source it responsibly or consider an alternative composting medium, such as coconut coir.

In summary, both coconut coir and peat moss are ideal composting mediums for use in RV composting toilets, like Nature’s Head. Each has its advantages when it comes to sustainability, odor control, and moisture retention.

Nature’s Head

Nature’s Head is a well-known brand in the RV composting toilet market. They offer compact and user-friendly composting toilets designed specifically for RVs and small spaces. The Nature’s Head Composting Toilet uses separate compartments for solid and liquid waste, making it easier to manage and maintain. Their toilets operate with low power consumption and require minimal water, making them an eco-friendly choice for RV users.


Sun-Mar is another reputable brand offering composting toilets suitable for RVs. They have a range of models, including the Excel NE and Compact, designed for small spaces and mobile environments. Sun-Mar composting toilets feature a patented Bio-drum™ system, which effectively breaks down waste into safe, odorless compost. These units also have venting systems to minimize odors and ensure a pleasant in-cabin experience.

Air Head

Air Head produces high-quality composting toilets for RVs, boats, and other mobile applications. The Air Head Composting Toilet is a popular choice for those looking to minimize their environmental impact on the road. It separates liquid and solid waste, ensuring efficient breakdown and reducing odors. The Air Head toilet uses a compact design for easy installation in a variety of RV layouts.


Separett is a Swedish brand that offers dedicated RV composting toilets like the Villa 9215. Known for their innovative design and high-quality materials, Separett composting toilets are both functional and user-friendly. They feature urine diversion technology that keeps liquid and solid waste separate, making the composting process more efficient and odor-free. Venting systems ensure fresh air circulation within the RV, contributing to a comfortable and hygienic environment.

For detailed reviews of composting toilets, see this article.

Benefits of Composting Toilets in RVs

Composting toilets bring several advantages to RV owners, particularly those who are conscious of their environmental impact. These benefits align with the growing trend of eco-friendly RVing.

Eco-friendliness: One of the primary benefits of composting toilets is their environmentally friendly nature. Since they don’t require flushing with water, they tremendously reduce freshwater consumption. Additionally, composting toilets eliminate the need for using harsh chemicals to treat waste, minimizing their environmental impact.

Space-saving: Composting toilets are a compact solution. Their design is space-efficient, taking up minimal room in your RV. This not only allows you to save space but also to allocate that extra space to other essential items or features in your RV.

Odor-free: Properly maintained composting toilets are essentially odorless. They help maintain the healthy balance of oxygen, moisture, and heat necessary for bacteria and microbes to break down waste. This decomposition process results in odor-free compost and a fresher environment inside your RV.

No need for a black water tank: With a composting toilet, there is no need to store and handle sewage using a black water tank. This eliminates the unpleasant task of emptying sewage at a dump station and the need for a black water hose.

Recyclable waste: Once the waste breaks down, you can use the resulting compost as a fertilizer for your plants. Composting toilets convert human waste into a useful resource, thus promoting sustainability.

Incorporating a composting toilet into your RV will not only provide you with a more eco-friendly and space-saving solution, but it will also make your RVing experience more convenient and enjoyable. So, if you’re looking to minimize your environmental footprint while enjoying the open road, a composting toilet is an excellent choice.

Drawbacks and Challenges

Composting toilets in RVs are known for their eco-friendly nature and potential cost savings, but they come with their own set of challenges and drawbacks. One of the primary concerns is the price. Composting toilets can be more expensive upfront when compared to traditional RV toilets. The investment, however, may pay off in the long run by reducing water usage and waste disposal costs.

There is a learning curve associated with using composting toilets in RVs. Owners and users must adjust to the process of separating liquid and solid waste, as well as the maintenance tasks required to keep the system running smoothly. This includes regularly adding organic materials like sawdust or coconut coir to aid in the composting process. Some users might find this new routine daunting or inconvenient.

Handling the waste can be less appealing for some people, especially when it comes to emptying solid waste from the composting unit. Although these units are designed to minimize odors, the task of emptying them might still be considered a drawback by some users. It is essential to follow instructions for waste disposal precisely to avoid any unpleasant experiences.

Adjustments might be necessary in terms of expectations, as the composting process takes time and requires patience. While the system is designed to break down waste into compost, this process isn’t as immediate as traditional flushing systems. Some people may find it challenging to adapt to the wait time for complete composting before disposing of the waste.

In summary, adopting a composting toilet system in your RV comes with a set of challenges, including a higher upfront cost, a learning curve, handling waste, and adjusting expectations. However, these drawbacks must be weighed against the system’s eco-friendly nature and potential cost savings for each individual RV owner.

Alternative Toilet Options

When considering a composting toilet for your RV, it’s important to also be aware of other alternatives. In this section, we will discuss two common options: Portable Toilets and Pit Toilets.

Portable Toilets

Portable toilets are a popular choice for RVers who want a versatile and convenient option. These toilets are easy to transport and can be used in various situations, such as camping or boating trips. A portable toilet typically consists of a waste-holding tank and a flush system that uses water or chemicals to rinse the bowl after each use.

One major advantage of portable toilets is that they do not require a connection to a sewer system or a black tank, making them perfect for off-grid RVing and remote locations. However, they do require regular emptying and cleaning of the waste-holding tank. Some popular portable toilets include the Thetford Porta Potti and the Dometic 970 series.

Pit Toilets

Pit toilets, also known as pit latrines, are a more primitive option for RVers who prefer to be off-grid and do not require the comforts of traditional RV toilets. A pit toilet is essentially a hole dug in the ground, lined with a removable seat or platform for users to sit on while they use the restroom.

Although pit toilets are a low-cost and low-maintenance option, there are some drawbacks to consider. The odor can be unpleasant, and there is no efficient method of waste disposal, as the pits must be manually cleaned or filled in once they become full. Additionally, this option may not be practical for RVers staying in populated campgrounds or areas where ground excavation is not permitted.

In conclusion, both portable toilets and pit toilets offer viable alternatives to composting toilets in RVs. When making a decision, consider factors such as cost, comfort, and convenience, as well as the environment and sanitation requirements of your travel destinations.

Video – How do Composting Toilets Work in RVs?

This video covers everything you need to know, want to know, and don’t know that you need to know about composting toilets in RVs.

Composting Toilets in RVs Video – How Do They work?

Frequently Asked Questions

How is waste disposed in RV composting toilets?

In RV composting toilets, waste is separated into solid and liquid waste chambers. Solid waste is combined with a composting medium, such as peat moss or coco coir, in the solid waste chamber. Microorganisms in the composting medium break down the solid waste, eventually converting it into compost. Liquid waste is directed to a separate chamber, which needs to be emptied more frequently.

What are the differences between popular RV composting toilet brands?

Different RV composting toilet brands offer varying features, designs, and capacities. The most popular brands include Nature’s Head, Air Head, and Sun-Mar. Common differences include the size of the waste chambers, type of composting medium used, ventilation systems, ease of maintenance, and price. It is essential to research and compare these brands to determine the best option for your specific RV and personal preferences.

Are there any odor issues with composting toilets in an RV?

Properly functioning composting toilets should not produce any foul odors, as they are designed with a ventilation system that helps eliminate smells. However, improper maintenance, inadequate ventilation, or overfilled waste chambers may lead to unpleasant odors. Regular maintenance and following the manufacturer’s guidelines can prevent odor issues.

How often should an RV composting toilet be emptied?

The frequency of emptying an RV composting toilet depends on usage and the size of the waste chambers. Generally, the liquid waste chamber should be emptied every 2-3 days or when it reaches its capacity. The solid waste compartment may need emptying every 2-4 weeks, depending on the number of users and the specific toilet model.

What is the maintenance required for composting toilets in an RV?

Maintaining a composting toilet in an RV includes regularly emptying both the liquid and solid waste compartments, cleaning the toilet bowl, and adding more composting medium when necessary. Periodic cleaning of the ventilation system and replacing filters should also be done according to the manufacturer’s guidelines. Proper maintenance ensures optimal performance and hygiene.

Can a household composting toilet be used in an RV?

While household composting toilets function similarly to those designed for RVs, they may not be suitable for direct installation due to size, weight, or power requirements. However, some household composting toilets can be modified or adapted for use in an RV with the help of a professional. It is crucial to ensure that the chosen toilet aligns with the dimensions, power supply, and plumbing system of the RV.

Photo Credits

Composting Toilets for RV’s: Adapted from Dave Ocomposting toilets. Used via Creative Commons License.