If you are looking to stretch your adventures beyond accessible water and sewer hookups while also being kind to the planet, a composting toilet may be right for your Airstream adventures. Below, you’ll find all of the information you need to learn about Airstream composting toilet options, availability, function, use, and more.
What Brand Of Composting Toilet Can I Order With My Airstream?
The AirHead composting toilet is currently available as an option on the REI Co-Op Special Edition Basecamp Travel Trailer.
Built ruggedly to explore and protect the outdoors, the REI Co-op Special Edition Basecamp is our most sustainable travel trailer to date. Constructed from environmentally friendly, lightweight materials, with innovative water conservation features and optional composting toilet and exclusive solar upgrade, your eco-footprint is not only lighter, it’s sure to satisfy your itch for adventure.
Located in the center of the REI Co-op Basecamp floor plan is the wet bath. This space-saving approach houses the shower and toilet in the same waterproof area. New and exclusive to the REI Co-op Special Edition is the option to choose a composting toilet. By eliminating the need for flushing, you use significantly less potable water stored in your 21-gallon fresh tank and also prolong the life of the 24-gallon combination holding tank. Also included in the 16-foot wet bath is the shower head passthrough port. By rinsing your gear (or yourself) off with the shower head outside, you're achieving the same goal of not filling up your holding tank and ultimately extending the time you can spend off grid.
What Are The Benefits Of Using A Composting Toilet On An Airstream?
Freedom To Camp Away From Hookups
The AirHead composting toilet is a waterless toilet that allows users to extend their time boondocking or camping away from main water and sewage hookups.
Environmentally Friendly: Water & Energy Savings
This toilet does not require fresh water for flushing, so your fresh water tank capacity will last longer. Urine from the toilet is diverted to the trailer’s below-floor holding tank, solids are collected in the solid container immediately below the toilet bowl, where they are ‘composted’ with coco pith or peat moss.
Agitator Use Fewer Odors / Easy and Safe Disposal
The solids are mixed after each use using a manually cranked agitator and the continuous 12v fan draws moisture vapor and any odors to the exterior.
How Does the AirHead Composting Toilet Work?
When the AirHead is charged with coir first, the agitator – when turned – immediately disperses the solid material after the toilet has been used, in a large area within the solids container. This increases evaporation by exposing the mass to a larger surface area of oxygen due to the absorbency of the coir. This exposure to oxygen also promotes the growth of aggressive and non-offensive odor producing aerobic bacteria. This has the effect of "seeding" the solids container with compostable food, so the next drop is exposed to already building bacteria. The bacterial action also produces heat, thereby increasing evaporation.
This separation of liquids and solids, plus the continuous flow of air allows aerobic decomposition to occur; the products of which when finished are non-offensive and safe when handled responsibly.
Composting Toilet Operating Instructions
Introduction
The AirHead toilet available for install in your REI Co-op Special Edition Basecamp is a waterless toilet, that allows users to extend their time boondocking/ camping away from mains water and sewage hookups.
This toilet does not require fresh water for flushing, so your fresh water tank capacity will last longer. Urine from the toilet is diverted to the trailer’s below-floor holding tank, solids are collected in the solid container immediately below the toilet bowl, where they are ‘composted’ with coco pith or peat moss. The solids are mixed after each use using a manually cranked agitator and the continuous 12v fan draws moisture vapor and any odors to the exterior.
This separation of liquids and solids, plus the continuous flow of air allows aerobic decomposition to occur; the products of which when finished are non-offensive and safe when handled responsibly.
AirHead toilets have been in use for over 20 years, providing users of small boats, tiny homes, and RVs more freedom from sewage hookups.
These User Instructions explain how to use the toilet and answer Frequently Asked Questions.
Using the AirHead toilet
Preparation:
Prepare coco pith brick (approx. 80 cubic inches) by putting it in a bucket or plastic bag and adding 1 1/2 to 2 quarts of water. Use less water if toilet will be used more frequently. Allow to hydrate overnight. Break up hydrated brick by hand to a loose, moist sawdust-like consistency. If using peat moss, add just enough water to prevent dusting or dust may be created which will clog the fan screen. Whatever material you use, the solids container must be about half full (as measured to top of solids container, not to the opening) of the hydrated brick material at the start.
Verify that the 12v fan is running, the sound cannot be heard externally but should be audible internally where it is located (Basecamp16: below the galley sink).
Type ‘one’ usage:
Lift lid. Women can use the AirHead like a standard toilet, except there is nothing to flush. Men may stand but should target angled surfaces to avoid splatters. Urine can land anywhere in the front half of the bowl. When seated, position yourself forward if necessary Close seat and lid on completion.
Type ‘two’ usage:
Lift lid. Depress lever adjacent to seat by pulling outward slightly, then down to open trap door. This will allow solid waste and toilet paper to enter solids container below. Rotate crank handle ½ turn or as necessary to bury each fresh use. Close trap door and lid on completion.
Cleaning:
A spray bottle of water is useful for bowl cleaning after each usage if necessary, to which a deodoriser can be added. For periodic hygiene cleans, clean the bowl and exterior of the toilet with a non-chlorine hard surface cleaner.
Managing solid container contents:
The peat will gradually absorb any liquid from each type 2 use and the fan will carry water vapor out of the vent. Moisture should be maintained so that toilet paper shreds as the agitator is turned. If papers wrap around the agitator, add more water using the spray bottle. The mixture should resemble damp, crumbly earth; not waterlogged or soup-like. When conditions inside the solids container are moist, the conditions are excellent for decomposition of the solids into humus.
The unit can be used dry, solids will dehydrate to an unnoticeable state, but toilet paper will not decompose. Moist conditions mask exhaust odour better than dry, hence maintaining a correct moisture content is recommended.
Holding tank level:
On small trailers with a combo tank (holding grey and black water), the urine will be emptied each time you dump grey water.
On other larger trailers with a dedicated black tank, when the AirHead toilet is fitted the black tank will now take urine only from the toilet, so the tank capacity will last much longer. Remember to monitor the black tank level and plan to empty it when you have a sewage hook-up.
Emptying the AirHead solids tank
When to empty:
When the trailer is in regular use, so long as the 12v fan is operating continuously, the solids container can be left between camping trips and the composting of solids will continue. Periodic cranking of the agitator handle can be helpful, to mix air into the solid mixture and break it up into smaller particles.
When the solid contents are 2” from the top of the container, the container needs emptying. Note: if you are leaving the trailer for several weeks, continued composting will reduce the solids level allowing further use on your return before emptying.
The Capacity Chart below shows likely emptying frequency by # of users (adults or children), assuming daily use by all occupants.
| # of users | Solid container capacity (in weeks) |
| 1 | 8 |
| 2 | 4 |
| 3 | 2.5 |
| 4 | 2 |
| 6 | 1.3 |
If you are putting the trailer into storage and cannot depend on continued 12v fan operation, then the solids container should be emptied.
80 solid deposits of 10 oz each, when reduced in size 60% due to evaporation, will take up 2.5 gallons of space (the balance of the 5 gallon AirHead solids container, when charged half full of coco pith at the start).
Removing the solid container:
- Follow normal hygiene practices such as wearing of gloves and washing hands afterwards.
- Loosen the thumbscrews (turn counter-clockwise) holding the toilet bowl to the solids container.
- Detach the vent hose from the rear of the toilet bowl.
- Detach the urine discharge hose using the quick-release connector on the side of the bowl.
- Lift the toilet bowl off and set aside.
- Cap the solids container with the lid provided (that comes loose with the AirHead toilet).
- Loosen the thumbscrew knobs holding the solid container to the 2 x s/steel floor brackets.
- Lift the solid container up and out of the bathroom, to transfer contents outside the trailer (see next section).
- The solids container may retain some peat in the very bottom of the container. There is no need to scrape this out if you are continuing to use the trailer since there are (most likely) active bacteria of decomposition present in the bottom ready to go to back to work.
Solid tank contents disposal:
Some users may be able to compost the solid container contents sufficiently in the trailer, before the container needs emptying. However as retention time from last use of not less than 3 months in summer is recommended (longer in colder climates), we expect most users will need to empty the solid container when the mix is still partially composted (not fully composted).
Composting can be accelerated by adding some liquid fertilizer/ sugar.
Disposal options for partially composted material include:
- Transfer the solids container contents into doubled compostable plastic bags (now readily available), for disposal via one of the following options:
- A refuse bin/ area, as you would dispose of infant diapers.
- A larger composting toilet, or municipal composting or incineration facility able to receive solid human waste.
- If you are emptying the solids container at home and have a domestic compositing area, you can transfer to a home composting bin for further composting (EG 12 months), before trenching in soil designated for ornamental plants (not food producing).
- Hydrating the mixture with water in the solids container, then flushing into a public sewer either at a campsite or at home.
Do’s and Don’ts
- DO leave the toilet seat and lid down at all times, other than when actually using the toilet. The seat has a seal to the bowl, which seals the toilet pan from the habitable space and allows the continuous 12v fan to draw air from both the solids container and urine hose/ holding tank, to the exterior.
- DO leave the 12v fan running at all times when there are contents in the toilet, to expel any odors and to keep the AirHead toilet ‘downwind’ of flying insects. Whilst there is a screen in the 12v fan housing, it is better to have negative air pressure also, so the toilet is not detectable. If you can smell the toilet from inside the bathroom, so can the bugs.
- DON’T let young children or children who cannot safely use the toilet in accordance with these instructions use the toilet without adult supervision. Do not allow children to play with this product.
Maintenance
- Ventilation fan: Remove and rinse the inline screen mounted on the vent hose cuff pushed into the rear of the toilet, to ensure it is clean and unobstructed, to maintain good ventilation. This should be done periodically, at least once per season, or if you start to detect odours from the toilet. Check that the ventilation pipe is intact and that its joints are tight. The return air screen on the side of the toilet bowl, should also be checked periodically to ensure it is clean and unobstructed.
- Urine discharge tube: Flush the urine tube periodically with vinegar and water, followed by occasion cleaning as needed using denture cleaner. Be alert to any backing up of urine at the bowl point of entry to the urine tube, which could indicate that the urine discharge tube is clogged. To clear clogged tube: Follow the denture cleaner manufacturer's instructions. Note recommended water temperature and ratio. Disconnect the quick-release connector and pour cleaning solution into bowl/ urine tube. Depress quick-release button as necessary to fill entire tube with cleaning solution. Allow cleaner to sit overnight in tube Drain solution by reconnecting quick-release and flush copious amounts of fresh water down the urine tube.
FAQ:
What is the benefit of the agitator, other composting toilets do not have this?
When the AirHead is charged with coir first, the agitator when turned immediately disperses the solid material after the toilet has been used, in a large area within the solids container. This increases evaporation by exposing the mass to a larger surface area of oxygen due to the absorbency of the coir. This exposure to oxygen also promotes the growth of aggressive and non-offensive odour producing aerobic bacteria. This has the effect of "seeding" the solids container with compostable food, so the next drop is exposed to already building bacteria. The bacterial action also produces heat, thereby increasing evaporation.
If I find the AirHead toilet does not meet my needs, can I remove it and fit a standard RV water flush toilet?
YES. The AirHead toilet install for a trailer was designed to be a direct substitute to the standard water flush toilet. The closet flange to the holding tank is still there, but has been blocked and covered, allowing the urine discharge hose to still discharge into the holding tank, with the AirHead toilet positioned over. The water supply pipe for the standard toilet is also still provided. If in the future you choose to refit a standard water flush toilet, the AirHead can be easily removed to allow install of the water flush toilet discharging to the holding tank.
What materials can I use as the composting medium?
| Composting agent | Performance |
| Peat moss | Best |
| Coco coir | Best |
| Paper pet bedding | Better |
| Corn cob cat litter | Better |
| Non kiln dried sawdust | Good |
| Coffee grounds | Good |
Technical information:
Dimensions:
Height: 19.75”
Length: 17.5”
Width: 14.125” toilet body, 17.875” overall
Seat height: 19”
Material:
Outer material: High-Density Polyethylene
Inner material: High-Density Polyethylene
Weight: 9.6 Kg, (all components).
8.0 Kg, (toilet body).
Volume:
Solid waste container: 4.3 gallons
Pipe dimensions:
Ventilation pipe: Ø 46 mm (outer diameter) (1.8”)
Urine hose: Ø 25.4 mm (outer diameter) (1”)
Power consumption: 0.0173 kwh/day