"Water has become imperilled, not through the deliberate actions of evil men...but through the small doings of many --far too many--ordinary people, doing things the way they have always done them. That's where the real danger lies." (Marq de Villiers, Water, 1999)
Self-contained Composting Toilets
Self-contained units are installed directly in the bathroom. They are available in both electric and non-electric versions.
Electric units plug into a regular 3-prong outlet to power a fan and a thermostatically-controlled heating element in the base of the unit. Usually you unplug the unit if it is not going to be used for a few days. Depending on the size of the unit, power usage varies between 80-150 watts.
Composting capacity varies with the size of the Bio-drum. Electric units normally have more capacity than non-electric units because they have extra warmth and air movement to enhance bacterial activity.
Although stated composting capacities can be doubled for short periods, Sun-Mar recommends a margin of safety, so choose a unit with more capacity than you think you need.
Advantages of Self-contained Units
- No plumbing required. Being waterless, no plumbing or water connection is necessary. This means the units are quick and easy to install since the only major task is to assemble the vent stack which comes with the unit.
- Economical. There is no need to purchase a separate toilet, so they are more economical than central units.
- Better suited to winter operation. Depending on your situation, it may be easier to keep the bathroom warm in winter than to warm the space that houses a central composting unit.
- Approvals not normally required. Most units evaporate all liquids during seasonal operation. Since the whole waste stream is recycled, approvals are not normally required.
- Easy to clean. All self-contained units have a bowl liner beneath the seat, which can be removed for cleaning whenever necessary.
- Attractive high-gloss finish. The high quality, high-gloss fibreglass finish is attractive and clean-looking and carries a 25 year guarantee.
Specifications and Rough-in Dimensions
Click here for specifications and rough-in dimensions.
Long considered the standard in composting toilet performance, the Excel is the preferred self-contained electric model for heavy or residential use.
The Excel is not only our best-selling unit, but also the first self-contained composting toilet to be certified by NSF (National Sanitation Foundation) in 1989. Since then, we have made many modifications to improve performance in all three chambers - evaporation, composting, and finishing. When you purchase an Excel, you are purchasing the composting toilet that sets the standard. The current model is the 4th generation Excel.
The Excel is ideal for residential use having been tested by NSF with 4 adults using the unit residentially for six months of continual use. In this test, the criteria were that the unit operated without odour and produced clean, safe compost. Of course, it did, and the Excel is presently the ONLY self-contained unit in the world to be tested, certified, and listed by NSF.
The Excel is also ideal for cottage use as the primary toilet at your camp or cabin, or for light commercial or workplace use. The 2" vent is attached at the top back of the unit and can be installed invisibly by running it through the wall and up the outside wall. For comfort the Excel has a sturdy detachable footrest which can be removed to pull out the finishing drawer.
Although the Excel can normally evaporate all liquids, a ½" emergency drain is fitted at the rear and this should be connected if the unit is to be used residentially or heavily, or if prolonged power outages are expected.
Composting Capacity: 3-4 Residential, 6-8 Weekend/Vacation
The Compact is an elegant low profile unit with the looks to complement any bathroom.
Sun-Mar engineers designed this low profile toilet by developing and patenting a new variable diameter Bio-drum which is small at the front and large at the rear. To maintain the uninterrupted lines of the Compact, a patented Bio-drum handle recesses into the body of the unit to mix and aerate the compost.
The Compact differs from the Excel in that all three chambers are smaller, which makes the Compact ideally suited to light residential or light to medium cottage use.
As with the Excel, a 2" vent stack attaches to the rear of the Compact and can be installed invisibly. A 1/2" emergency drain at the rear offers protection against heavy or residential use, or prolonged power outage.
Composting Capacity: 1-2 Residential, 3-4 Weekend/Vacation
With a width of only 19" and depth of 22", even a closet or small corner can be turned into a bathroom!
The Space Saver is a standard three chamber unit designed specifically for situations where space is extremely limited.
The Space Saver is fitted with the same kind of high quality turbo-fan as other electric units have. The difference is that on the Space Saver, a 3" vent stack is included.
The Space Saver has almost the same size Bio-drum as the Compact, so composting capacity is similar to that of the Compact. On the other hand, evaporation is limited by the smaller heater and evaporating surface, so the safety drains should be connected. Click for more information on handling excess liquid.
Composting Capacity: 1-2 Residential, 3-4 Weekend/Vacation
Excel NE (Non-electric)
Launched in 1981, the Excel NE has long been the standard toilet for those living off the grid.
The success of the Excel design meant that a three chamber unit could be specifically designed for those with NO continuous 110 volt supply. A 1998 redesign gave the unit a rounded look, and recessed the drum handle.
The Excel NE has no fan or heater. Odorless operation is achieved by a 4" vent mounted at the top rear of the unit which acts like a chimney on a wood stove. For good air movement the vent should be installed vertically and to 2-3 feet above the peak of the roof.
The optional 12 volt Fan should be installed if you need to incorporate any bends in in the vent pipe. A maximum of two (2) 45° bends is recommended, even with the fan. If the Excel NE is used residentially or heavily, or is in a place which is subject to downdraft, the optional 12 volt fan should be installed in the vent stack. This fan draws 1.4 watts and can be powered by a solar panel and 12 volt marine battery. Please click here for more information on the 12 volt fan.
Evaporating capacity on the Excel NE is variable, so the 1" drain at the rear should be connected to an approved drain pit, container, or other facility. Please click for more information on handling excess liquid.
Composting Capacity: 2-3 Residential, 5-7 Weekend/Vacation
For use with intermittent power supply or if there is no power supply yet.
The Excel AC/DC is a standard 110 volt Excel unit, but with 1" safety drains at the rear and dual (2" and 4") vent stacks.The unit uses the regular 2" vent when 110 volt power is available and defaults to the 4" vent when it is not. A 12 volt 1.4 Watt fan is included for use in the 4" vent stack. Click here for more information on the 12 volt fan.
The Excel AC/DC is for those with generators operating over 12 hours per day, or for people that expect to have continuous 110 volt power available in the future.
The 1" overflow drain on the Excel AC/DC should be connected if the unit is being used heavily in AC mode, and if it is being used at all in DC or non-electric mode. It will only evaporate all liquids while working in the AC mode continuously. Click for more information on handling excess liquid.
PLEASE NOTE: Effective January 2011, the Excel AC/DC consists of two parts - an Excel and an AC/DC kit.
In AC Mode: 3-5 Residential, 6-8 Weekend/Vacation
In DC Mode: 2-3 Residential, 5-7 Weekend/Vacation
Voltage: N/A, Optional 12 Volt Fan