How to choose the right composting toilet for an RV

Last updated on November 5 2023

This guide breaks down the factors to consider when selecting a composting toilet. We cover the different types and their features as well as installation considerations and how to match the right toilet with specific needs, whether it’s for a caravan or RV, a tiny home or if you are living off-grid in a cabin.

When it comes to embracing a sustainable lifestyle, every choice you make matters – even down to the type of toilet you use. Composting toilets have become an eco-friendly alternative to traditional flush toilets, helping conserve water, reduce pollution, and recycle nutrients.

This guide will help you make an informed decision that aligns with your environmental goals and lifestyle.

Understand your composting toilet needs

Before diving into the world of composting toilets, you should assess your specific needs. Where do you want to install the composting toilet? Does it need to go in a tiny home, cabin, boat, or RV? You should consider the available space, power sources, and usage frequency, as these options may mean slightly different requirements for the toilet you need and will help you narrow down your options.

What is a composting toilet?

A composting toilet is not as gross as it may sound. When we first thought of a composting toilet, we had images of the drop toilets that can be found in national parks and parklands across the globe, or even things like a bucket.

The great news is that composting toilets are nothing like this and are modern ‘normal looking’ toilets that utilize the natural decomposition process to break down and recycle human waste into nutrient-rich compost without the use of water.

The composting toilets are built to allow bacteria and microorganisms to break down our human waste into compost, using inputs such as temperature, moisture and aeration.

Composting toilets can now be used in specialized locations including caravans and RVs, campers, trailers, and other mobile living spaces.

Types of composting toilets for RVs

We are going to focus on the types of composting toilets thaat can be used in RVs, caravans and similar smaller areas.

These toilets are adapted to fit an RV’s smaller, confined spaces. Following are some common types of composting toilets for RVs:

1. Self-Contained RV Composting Toilet: This type of composting toilet is an all-in-one unit that fits directly into the RV’s bathroom space. It doesn’t require external composting bins or systems. Users deposit waste into the toilet, which then goes through the composting process within the unit. These toilets usually include a ventilation system to aid in decomposition and odor control.
2. Centralized RV Composting Toilet System: Some larger RVs or motorhomes might opt for a centralized composting toilet system. In this setup, waste from multiple toilets in the RV is directed to a central composting unit, which manages the composting process. This can be beneficial for RVs with multiple bathrooms or cabins.
3. Urine-Diverting RV Composting Toilet: These toilets separate urine from solid waste, which improves odor control and composting efficiency. The separated urine can be collected in a separate tank for disposal or other uses. The solid waste undergoes composting in a dedicated chamber with proper aeration.
4. Compact RV Composting Toilet: These toilets are designed to fit into small RV bathrooms with limited space. They prioritize efficient use of available areas while still offering the benefits of composting waste management.
5. Electric RV Composting Toilet: Some RV composting toilets have electric components, such as fans or heaters, to regulate temperature, moisture, and ventilation. These features can enhance the composting process and odor control.
6. Vermicomposting RV Toilet: While less common, RV composting toilets incorporate worms to aid in the decomposition process. Worms help break down waste and accelerate composting. This type might require more maintenance and careful management.
7. DIY RV Composting Toilet: Some RV owners use DIY methods to create their own composting toilet setups. These can vary widely in design and effectiveness, but they allow for customization according to individual needs.

It’s important to note that the effectiveness of composting toilets depends on proper usage, maintenance, and management of temperature, moisture, and airflow. Composting toilets can be a sustainable and efficient solution for waste management, especially in areas with limited access to sewage systems or in environmentally sensitive areas. However, your specific type of composting toilet should be based on your needs, available resources, and local regulations.

How do composting toilets work?

1. RV composting toilets work by utilizing the principles of composting to break down human waste into nutrient-rich compost in the confined space of a recreational vehicle (RV). These toilets are specifically designed to address the challenges of waste management in mobile living spaces.
2. Urine and Solid Waste Separation: Many RV composting toilets incorporate a urine-diverting system. This separation reduces odors, minimizes moisture in the composting chamber, and improves composting. Urine is usually directed to a separate container or holding tank.
3. Composting Chamber: Solid waste and an organic composting medium like coconut coir or peat moss are deposited into a composting chamber. This medium provides the necessary carbon-to-nitrogen ratio for efficient composting.
4. Aeration and Ventilation: Proper aeration is crucial for the composting process. RV composting toilets have ventilation systems or fans that supply a continuous flow of air to the composting chamber. This airflow supports aerobic decomposition by providing oxygen to the microorganisms that break down the waste.
5. Decomposition and Microbial Activity: As waste decomposes, aerobic bacteria and other microorganisms break down organic matter, including solids, into compost. Combining the composting medium, oxygen, and microorganisms contributes to the breakdown process.
6. Temperature and Moisture Control: RV composting toilets often include features to regulate temperature and moisture levels within the composting chamber. These factors influence the decomposition rate and the resulting compost quality.
7. Maintenance: Users need to periodically add more composting medium and manage ventilation settings to ensure optimal conditions for composting. Depending on usage and the toilet’s capacity, maintenance might be required every few days to weeks.
8. Compost Removal: Over time, the waste breaks down into compost. Users will eventually need to empty the composting chamber. The resulting compost can be used as a soil amendment or disposed of in designated composting areas.
9. Odor Control: Properly designed RV composting toilets incorporate odor control mechanisms, such as separating urine and solid waste and the continuous flow of air to prevent odors from escaping the unit.
10. It’s important to note that while RV composting toilets can significantly reduce water usage and offer a sustainable waste management solution, they require proper usage and maintenance to ensure effective composting and odor control. Following the manufacturer’s guidelines, maintaining the composting medium, and understanding the needs of your specific RV composting toilet model are essential for a successful experience.

Major features to look for when choosing a composting toilet

Ventilation and odor control

Efficient ventilation is key to controlling odors and promoting decomposition. Look for composting toilets with effective ventilation systems that ensure continuous airflow within the chamber. Proper ventilation also supports aerobic decomposition, which minimizes odors.

Urine-diverting system

Many composting toilets feature a urine-diverting mechanism separating liquid and solid waste. This separation prevents excess moisture, which is critical for efficient composting and odor control.

Installation and Maintenance

Consider the installation process and ongoing maintenance requirements. Look for user-friendly models that come with clear instructions for setup and maintenance routines. Assess the ease of emptying the compost chamber, adding bulking agents, and ensuring proper ventilation. Be sure to understand how it might fit in your particular area where you want to use it.

Capacity and Usage Frequency

Determine the expected usage frequency and the capacity of the composting chamber. Smaller chambers may require more frequent emptying, so choose a size that suits your needs without causing inconvenience.

Environmental Impact

Research the environmental impact of the composting toilet you’re considering. Review factors such as water savings, pollution reduction, and the potential for creating nutrient-rich compost. Opt for a model that aligns with your sustainability goals.

Benefits of using a composting toilet

Using a composting toilet in an RV offers several benefits, making it a popular choice among RV enthusiasts who are looking for sustainable and efficient waste disposal solutions. Here are some of the advantages:

1. Water conservation: Composting toilets do not require any water for flushing, which helps you conserve your freshwater supply, especially when boondocking or camping in areas with limited access to water.
2. Reduced waste and odor: Composting toilets break down waste into compost through natural processes, significantly reducing the volume of waste and minimizing unpleasant odors. Many models have venting systems that further help with odor control.
3. Environmentally friendly: Composting toilets are eco-friendly because they do not use water and do not contribute to the pollution associated with traditional sewage systems. They also produce compost that can be used for gardening, reducing waste even further.
4. No waste tank: Traditional RV toilets use a black water tank (waste tank) to store waste, which can be messy and require frequent dumping. Composting toilets eliminate the need for a black tank, simplifying the RV plumbing system.
5. Extended boondocking: Since composting toilets do not rely on water or external sewage systems, they extend your ability to boondock or camp off-grid for longer periods without needing to find dump stations.
6. Low maintenance: Composting toilets are relatively low-maintenance. They typically require periodic emptying and compost maintenance, which is less frequent than emptying black tanks in conventional RV systems.
7. Space efficiency: Composting toilets are often smaller and more space-efficient than traditional RV toilets and tanks, allowing you to make the most of the available interior space in your RV.
8. Cost savings: Over time, composting toilets can save you money on water bills and the costs associated with maintaining traditional RV sewage systems.
9. No chemicals: Unlike some chemical treatments used in traditional RV toilets, composting toilets don’t require the use of harmful chemicals, making them safer for the environment and your health.
10. No freeze risk: In cold weather, there is no risk of freezing and damaging the plumbing associated with composting toilets, as there is with some traditional RV toilets. You can read more about how to look after a standard portable toilet in winter here to help you decide.

FAQs

People have a range of questions about composting toilets, as they seek to understand how these innovative systems work, their benefits, installation process, maintenance, and more. Here are some common questions being asked.

Are composting toilets odor-free?

Yes they are. Like any portable toilet, there will always be some small odors, but if you understand how to manage your toilet, there is minimal smell.

How is solid waste turned into compost in a composting toilet?

Composting toilets use a controlled, aerobic (oxygen-dependent) decomposition process to turn solid waste into compost. Here’s a simplified explanation of how this process works:

1. Collection: When you use a composting toilet, solid waste (feces and toilet paper) is deposited into a specially designed container or chamber within the toilet. Some models have separate chambers for urine and solid waste.
2. Microbial Activity: Microorganisms, including bacteria and fungi, naturally present in the waste and added through the use of a bulking agent (such as peat moss, coconut coir, or sawdust), begin breaking down the waste immediately upon contact. The bulking agent helps create air pockets and balance the carbon-to-nitrogen ratio, facilitating decomposition.
3. Ventilation: Composting toilets are equipped with ventilation systems that facilitate air circulation and help control odor. The ventilation system typically includes a fan and a vent pipe that removes excess moisture and odorous gases, promoting aerobic conditions.
4. Temperature Control: Microbial activity is most effective within a specific temperature range (usually between 110°F to 160°F or 43°C to 71°C). The composting toilet is designed to maintain an optimal temperature for decomposition, which aids in speeding up the process.
5. Composting Chamber: Over time, as waste accumulates, it is continuously broken down by the microorganisms. The composting chamber is designed to retain the waste until it is fully decomposed. As the waste decomposes, it becomes smaller in volume.
6. Compost Harvesting: When the composting chamber is full, the mature compost is removed. The time it takes for waste to fully decompose varies depending on factors like temperature, ventilation, and usage, but it typically ranges from a few months to a year.
7. Maturation: The removed compost is left to mature for an additional period outside the toilet. During this time, any remaining pathogens are killed off, and the compost becomes safe and stable for use in gardening or landscaping.

It’s important to follow the manufacturer’s instructions for maintenance and usage of your specific composting toilet model to ensure proper operation.

Regularly adding bulking agents, monitoring the composting process, and periodically emptying the composting chamber are essential tasks to maintain the functionality and odor control of a composting toilet.

Additionally, composting toilets are typically designed to handle only solid waste, while liquid waste (urine) is usually diverted separately to minimize moisture in the composting chamber.

Can you use a composting toilet in cold climates?

Yes you can. Because there is no plumbing involved, the issues that can be experienced by traditional portable toilets don’t occur.

Summary

Selecting the right composting toilet is a thoughtful decision that combines practicality, sustainability, and efficiency. By understanding your needs, considering key features like ventilation, urine diversion, and installation, and researching reputable brands, you’ll be well-equipped to make an informed choice.

It’s important to note that composting toilets may have a learning curve, and users need to follow proper maintenance and usage guidelines. Additionally, composting toilets are an investment upfront, but many RV enthusiasts find that the long-term benefits and sustainability aspects make them a worthwhile choice for their RV adventures.

About the Author
Carrie has loved camping and being outdoors since she was a small child. After travelling extensively throughout the world, Carrie and her husband Chad really found their love of exploring by RV. Even though this is their preferred mode of travel these days, you can still find them in a tent too. Wherever they are, you can be sure they are also enjoying good food and wine.