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Before we even bought our first RV, we knew we wanted a composting toilet for the RV. Traditional RV toilets sounded scary – especially the part about dumping sewage from the black tank out through a hose. (As we later found out, dumping the black tank really isn’t so bad!)
We read countless articles about different kinds of RV toilets, and composting toilets jumped out at us (well, at me) as the obvious choice.
In the end, our adventure with a composting toilet lasted only two weeks. In retrospect, we shouldn’t have gone from a residential toilet straight to a bucket toilet, but …. live and learn. We use a portable camping toilet now, if you’re interested in checking that out.
But we have used quite a few types of RV toilets and we want to help you learn from our successes and our mistakes. A composting toilet for the RV could have gone great for us, if we’d known a bit more at the time.
To help you decide if it’s right for you, here’s everything we know about composting toilet for RVs – including the 6 best composting toilets available to RVers.
What is a Composting Toilet?
A composting toilet is a type of toilet that doesn’t use any water for flushing. Instead, it usually separates the liquids (#1) from the solids (#2) to prevent your waste from turning into sewage. (That’s where the smell comes from.)
The liquids go into a container, which can be emptied on its own into a toilet, or diluted and sprinkled onto the ground.
The solids get mixed in with peat moss, coconut coir, or some other organic medium. This dries them out, keeps odor down, and starts the decomposition process for your waste, which eventually turns it into compost. You know – the stuff you can use as fertilizer.
When the compost bin fills up (typically this takes a few weeks), you can empty it into a compostable bag and just toss the whole thing into the trash.
Why use a Composting Toilet in your RV?
There are several benefits to using a composting toilet in an RV. That’s why we were so convinced at first that we needed one! Here are the main reasons why we wanted a composting toilet.
Eliminate the Black Tank
Our Class A RV came with a Dometic® 310 China Bowl Stool connected to a 40 gallon black tank. We figured we’d need to dump the tank every 7-10 days or so with the two of us living in it full time. That’s a lot of trips to the dump station to empty sewage from the black tank. (Granted, we’d still need to go to the dump station to empty the gray tank, but this would let us go longer between trips.)
Also, remember that scene in RV with the sewer line explosion? We’d heard so many horror stories about dumping the black tank that we were wary about trying it at first. Using a composting toilet in your RV allows you to skip that whole process, since your waste isn’t entering your RV’s holding tanks at all. There’s no need to deal with sewage in the “stinky slinky.”
Save Fresh Water
Composting toilets do not require water. They are dry toilets that use organic materials to treat human waste. For us, that meant the 75 gallon fresh water tank would last longer for showers, dish-washing and of course for drinking (which we run through a water purification system – read our Berkey Review).
If you’re boondocking or dry camping out in the wild, you know that water is a precious resource. We thought that if we could save the water we might otherwise use to flush our toilet, we could stay out longer especially if it’s an epic spot.
Increase Gray Tank Capacity
Not using the black tank for a traditional RV toilet would give us the option to combine it with the gray tank and use it as an overflow. This would allow us to increase our gray tank capacity. Again, the fewer trips to the dump station, the better.
For those taking on a DIY van build, you may be install a bigger gray tank or use that valuable space for other components.
Other Benefits
- Reduced Odor: This wasn’t our experience, but we’ve read a lot from people who have found that their composting toilet smells less than their traditional water-flush RV toilet. This is because you’re separating liquids from solids, and it’s the combination of both that create that sewage smell.
- Eco-friendly: Because you aren’t using fresh water to flush, you’re not only preserving water to allow you to camp longer – you’re using less water in general.
The Best Composting Toilet for RVs
Table of Contents
1. Nature’s Head Composting Toilet
Cost: $1,030 (check current price)
Solid Capacity: Full time for two is approximately 3 to 4 weeks
Liquid Capacity: 2.2 gallons
Features: 12 volt fan
Warranty: 5 years
Made in USA
The Nature’s Head is the most popular composting toilet on the market. It’s relatively easy to install (as long as you can vent to the outside in your RV), as it has a 12-volt fan to keep odors down.
It’s not the most expensive (nor the least expensive) composting toilet on the market, and it’s lightweight and has a smaller footprint than other brands.
The customer service is reported to be excellent which is always important when spending this kind of money on a product that you’ll be using daily.
Nature’s Head was the brand we were seriously considering before we tried the composting bucket toilet.
2. Air Head Dry Composting Toilet
Cost: $1,095 (check current price)
Solid Capacity: Full time for two adults is approximately 60 uses for 1 month
Liquid Capacity: 2 gallons
Features: 12 volt fan
Warranty: 5 years
Made in USA
The Air Head markets itself as the most compact composting toilet available. The cost and capacity are similar to the Nature’s Head, but the footprint of this toilet might work better in a smaller RV.
3. Trelino Composting Toilet
Cost: $399-$629 (check current price)
Solid Capacity: 1.6-2.6 gallons
Liquid Capacity: 1.2-2.6 gallons
Warranty: 2 years
Trelino composting toilets are compact, easy to use, and available in three sizes—small, medium, and large—ensuring it fits seamlessly into any camper setup. The Trelino Evo composting toilet model is very popular in smaller RV with limited space. The smallest Trelino Evo measures 13 x 15.4 x 11.7 inches, while the largest measures 13 x 15.4 x 16.9 inches. We’ve met a few Class B van owners who use the Trelino Evo S in their camper and rave about how much they love it.
4. Separett Composting Toilet
Cost: $989 (check current price)
Solid Capacity: Full time use for a family is approximately 3 weeks
Liquid Capacity: 50L ejector tank
Warranty: 5 years
Separett is a manufacturer in Sweden that makes several urine diverting composting toilets for use in RVs. The model that is commonly sold in the U.S. is the Separett Villa 9215.
5. Sun-Mar Urine Diverting Toilet
Cost: $699 (check current price)
Solid Capacity: n/a
Liquid Capacity: n/a
Features: 12 volt fan
Warranty: 5 years for the tank, 3 years for all other components
Sun-Mar has several types of composting toilets. The Sun-Mar GTG is their urine diverting toilet and the least expensive model. This design is similar to most composting toilets: a bottle for liquids, a holding container for solids and whatever organic matter you choose to add, and a small fan to divert odors outside.
Other composting toilets by Sun-Mar takes things a step further and focuses on optimizing the composting process. They’ve patented a special Bio-Drum with an evaporation chamber that helps speed the breakdown of solids into compost. There’s no need to empty the liquids, since the toilet evaporates them for you!
6. OGO Origin Composting Toilet
Cost: $984.99 (check current price)
Solid Capacity: 25-30 solids uses
Liquid Capacity: 2.4 gallons
Features: Electric Agitator System
Warranty: n/a
Manufactured and Assembled in Ohio
We discovered the OGO composting toilet while checking out a customer camper van build. This composting toilet has several features worth highlighting including an electric agitator, liquid level sensor and an optional drain kit to divert the urine into the RV’s black tank.
7. Bucket Composting Toilet
Cost: $10+
Solid and Liquid Capacity: 5 gallons
This was the first (and only) composting toilet we tried, because we couldn’t find a good place to vent a more elaborate setup in our first RV.
It’s by far the most affordable option, especially if you don’t care much about how it looks in your bathroom. We dressed ours up with a box to hide the bucket and put a toilet seat on top, but you can go pretty simple with this one if you’re feeling adventurous.
While you can use a bucket composting toilet without diverting the urine, it requires figuring out the the right material such as sawdust to dry everything out and prevent bacterial growth. When the bucket is full, just empty into a trash bag and start over again!
To divert the urine in a bucket composting toilet, you will need to buy an aftermarket urine diverter. At $65, it is still more affordable than the urine diverting toilets listed above.
The bucket toilet wasn’t for us in the long run (we like our portable RV toilet), but if you’re interested in using one as a composting toilet for your RV, check out The Humanure Handbook.
Things to Consider Before Getting a Composting Toilet for Your RV
1. Space
The first thing we did was measure the available space to install a composting toilet in the RV. These toilets can get pretty expensive, so it’s very important to measure twice (or more) to make sure the toilet will fit before you buy.
2. Installation
Many composting toilets require ventilation and power for the fan. You’ll want a way to wire the fan into your onboard electric system, and also a good place to route the vent hose from your bathroom to the outside. Be aware that this generally means cutting a hole in the wall of your RV.
3. Organic Material
To put it simply, organic material is what helps dry your poop and turn it into compost. It’s a very important part of the process! Make sure you have a place to store materials such as sawdust or coco fiber, which can take up a lot of space. Another thing to consider is sourcing. Will you be camped in places where you can buy these materials as you run out?
4. Cost
There is a significant difference between the $10 DIY bucket toilet and the $1,000+ composting toilet. After taxes, shipping and installation, an RV composting toilet could end up costing a lot more than expected. Make sure it’s worth it to you before you invest.
5. Dumping
No matter which toilet you choose for your RV, you’re going to have to empty it somewhere. (If you find a way around this, let us know.)
Dumping a composting toilet is different than dumping a traditional toilet.
While you don’t have a black tank of sewage to manage, you still have to find an appropriate place to dump the liquids. This might mean carrying a bottle of your pee through a parking lot to a public toilet or pit toilet to dump it. There is also the option to connect the liquid diverter to the grey tank system in the RV.
For the solids, you’ll need to empty the bin into a bag for disposal in a trash can. Make sure to check with the waste management company in your area for proper humane waste disposal. If you’re looking to add the solid waste to a compost pile, make sure to do your research. Properly composting human waste has different temperature requirements among other things. Again, you will want to check the local ordinance on composting human waste.
6. Capacity
As with any RV toilet, a solo traveler or a couple will take more time to fill up a composting toilet than a big family. If you have lots of people making “deposits,” it’s very possible that you could fill up the solids bin before the waste has had time to turn into compost. Something to keep in mind when thinking about the emptying process.
Composting Toilet FAQs
If you’re just looking for some quick answers to your most burning questions about composting toilets, you’ve come to the right place. Here are some short and sweet answers to all of the most common questions about composting toilets that we can think of.
How does a composting toilet work in an RV?
Basically, a composting toilet separates liquids from solids, which means that you don’t end up with any sewage.
You’ll have a separate liquid tank, which can be dumped in any public toilet or sewer drain, and a solid compost bin, where your solid deposits get mixed with composting material to form humus. (NOT to be confused with hummus—this is just the organic material you find in fertilizer that helps plants grow.)
How do you use a composting toilet?
In much the same way that you use a regular toilet, except that you do have to be careful not to mix any liquids and solids together when you “go.” This can be more difficult for women than for men.
When you’re finished, the flushing process is similar, except that you’ll use little to no water. You’ll also have a hand crank or something similar to mix your newest solid waste in with your composting material.
How much does a composting toilet cost?
$10 – $1,000+. As with just about anything in the world of RVers, you can spend as much or as little as you want. We’ve seen toilets as simple as a 5-gallon bucket full of sawdust, with a makeshift seat on top, all the way to an elaborate toilet that runs on electricity and costs thousands of dollars.
The composting toilets listed above are actually a good representation of what’s out there in terms of price for urine diverting composting toilets.
What is a composting toilet system?
It’s a system for using your toilet to compost your waste! All joking aside, a composting toilet is a means of turning your waste into usable material, conserving drinking water, and avoiding the need to dump any sewage from your RV’s black tank.
Do you have to empty a composting toilet?
Yes. With a composting toilet, liquids and solids go to different places. You’ll need to empty the liquid bottle more often, since it’s got a smaller capacity and isn’t breaking down the way your solids are. But you will need to empty your solids, too.
And here’s how …
How do you empty a composting toilet?
Liquids can be dumped into a public toilet or sewer, or diluted and scattered on the ground (depending on where you are).
Solids will slowly decompose in your tank until they’re well on their way to becoming fertilizer. At that point, just put the whole bin’s worth of “stuff” into a compostable bag and toss it in a dumpster.
What do you do with composting toilet waste?
There’s not much you can do with the liquids (apart from dumping them), but you can do some cool stuff with the compost that comes from your solid waste. Because it gradually breaks down into fertilizer, you could use it on any plants you travel with, or on a home garden if you still have a sticks and bricks home.
Of course, you can also just toss it. The choice is yours.
How often do you have to empty a composting toilet?
This depends on how many people you have, and how much all of those people eat and drink. On average, we’ve seen that liquid bottles tend to fill up in 2 days or so with 2 adults using the toilet full time. Solids take longer—maybe 2-3 weeks for 2 adults.
Summary
Overall, composting toilets can be a great option for RVers. They aren’t as portable as a porta-potty or a cassette toilet, but they’re a more portable option than the traditional porcelain (or plastic) bowl. They are enormous water-savers, and can be more pleasant to dump than other RV toilets (though you will likely be dumping liquids more often).
If you’re trying to decide what kind of toilet to use in your own RV, check out our articles on other traditional RV toilet alternatives: cassette toilets and portable toilets.
Has anyone experimented with cat litter as an absorber?
Excellent article. You do need to be careful, though, before using your solid waste on your household plants. As I recall, the Humanure book says it takes about a year for it to break down enough for safe use on plants. Three large bins were recommended for use if you live in a rural area with a large backyard. The left hand bin is for recent waste. When it’s full, you move it to the center position of the three bins, and wait a year for it to break down to safe levels. The right hand bin is for compost that’s ready to use.
I bought this nature’s head RV self contained composting toilet to be installed in my RV. It’s an appropriate option. This product has durable construction with stainless steel hardware, simple to disassemble for easy dumping, features a low volume fan inside the toilet’s head to dissipate odor effectively. I was also thrilled to see how well it did, keeping my bathroom odor-free.
Very good article, we are seriously considering a composting toilet, for two reasons. Don’t have to dump a black tank, as well as using the existing black tank for extra grey tank capacity. I do have a question though, how would we change over the black tank, for grey water holding?
thanks peace and love
Dan and Laurie
You’re wrong about the bucket toilet. We have a urine diverting composting toilet made from a bucket in our RV. There is a urine diverting funnel made by a gentleman on Etsy / eBay for $30. The funnel fits on a 5 gallon bucket. You just have to get some plumbing supplies to cap off your black water tank so that the funnel tubing can go down to the now gray water tank. I used a old dining room chair that I cut off the back. We cut a hole in the top for the toilet seat and screwed it down. It’s easy now to take off the chair to empty the bucket when it’s full. I think I spent less than $50 to do the whole thing. Instead of spending hundreds of dollars on a expensive composting toilet. We found that red cedar works the best for the bucket.
Thanks for the information Ramona. The post has been updated.