Composting Toilets

Sun Mar Composting Toilets

Sun Mar is the world leader in home composting technology. Sun Mar offers electric composting toilets and larger systems, in addition to the toilets shown on this page.

For selecting the Model of Composting Toilet that best suits your needs:

Composting Toilet Model Selector

Excel NE

      The success of the Excel design meant that a three chamber unit could be specifically designed for those with NO continuous 110 volt supply. First launched in 1981, the Excel NE has long been the standard toilet for those living off the grid. 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 as close to vertical as possible. If the Excel NE is used residentially or heavily, or is in a place which is subject to downdraft, an optional 12 volt fan should be installed in the vent stack. This fan draws 1.9 watts and can be powered by a solar panel and 12 volt battery. The fan should also be installed if there is to be any bends in the vent stack, as the "chimney effect" is negated by a bend. 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. Ask for more information on handling excess liquid. $1445

Centrex 1000 NE

     The Centrex 1000 NE was recently re-engineered for better compost flow to include input doors on the left and an output door on the right. This output door is only open when the drum is rotated backwards to extract compost. Other changes include a larger finishing drawer, easier access for maintenance, and a redesigned access port which is secured by a catch.

      All Central units, including the 1000 series are now fitted with a removable evaporating tray under the drum screen in the evaporating chamber. This trays helps to trap any peat moss debris, and provides an extra evaporating surface. In light to medium seasonal use the 1000 is typically able to hold compost for the full season, and compost needs extraction only in the Spring. The Centrex 1000 NE does not normally need a 12 Volt fan for the 4" stack, but a 1.9 Watt fan is available if required (where a bend needs to be installed in the vent stack, a 12 Volt fan is required). All 1000 series units are supplied with a 1" drain hose which should be connected to the 1" drain at the bottom left of the unit. Ask for more information about handling excess liquid.

     The 1000 series is designed only for use with 1 pint flush toilets (purchased separately). $1445

2000 AF/NE

      Perfect for medium to heavy seasonal or light residential use, the 2000 allows for both a longer composting cycle, and larger waste volumes. The increased surface area in the evaporating chamber coupled with the larger heating element also provides better evaporation on electric units. When used seasonally by up to 5-7 adults, compost will normally only need removing annually each spring. In residential use compost will have to be extracted more frequently.

      The Centrex 2000 A/F NE is designed for use with a Sun-Mar Dry Toilet (purchased separately). This unit is ideal for those who do not have water, but still want the composting action to take place outside of the bathroom area. The Centrex 2000 AF/NE is the non-electric version of the Centrex 2000 AF which is fitted with a 4" vent stack. Installation of a 12 Volt fan is required on this model, and included in the box.

      The Centrex 2000 A/F NE is supplied with a 29 ½" pipe piece (10" diameter). This is long enough if the floor of the bathroom is up to 38" above the surface that the composter is placed on. The pipe piece can be cut to size and additional pieces ordered if necessary. With the lower evaporation capacity that comes with the lack of an electric heater, the overflow drain should be installed with this unit as there will be overflow. Ask for more information on handling excess liquid. $1745

Centrex 3000 NE

     The Centrex 3000 NE is a new and improved continuous flow design for very heavy cottage or medium residential use. With a continuous flow system, rotation of the drum moves compost along the larger and longer 3000 series drum, before it drops automatically into the collection housing at the end of the unit. Under normal operating conditions the drum will not have to be turned backwards for emptying.

      When used seasonally by up to 8 or 9 adults, compost will normally only need to be removed annually at the beginning of the following season. If needed, additional collection chambers are available for long term compost storage. The Centrex 3000 NE also features a 4" vent stack which may be used to vent the unit when no electricity is present. The price of the unit includes an optional 12 volt fan that we recommend installing in the vent stack, especially if you need to put a bend in the vent as shown at right. No electricity, except the optional fan mentioned above, is required to operate this unit.

     All 3000 series units are supplied with a 1" drain hose which should be connected to the 1" drain at the bottom left of the unit. Ask for more information on handling excess liquid.

     This unit is for use with a Sealand low flush toilet, purchased separately.    $1845

Dry Toilet

     This elegant Sun-Mar Dry Toilet is designed for use with the waterless Centrex A/F and Centrex A/F NE family of central composting systems. Available in either White or Bone, the Dry Toilet has a seat height of 15" and a regular sized toilet seat.

     The vent system on all A/F units continuously draws air down the toilet to prevetn odors in the bathroom. However, if the toilet is too high above the composter for air to be drawn down, the Dry Toilet should be vented directly. To do this, a 3" or 4" vent pipe can be installed at the rear left or rear right of the toilet, and, if necessary, a 12 Volt fan can be fitted in a section of 4" vent pipe to enhance air flow. All Dry Toilets include a bowl liner that fits beneath the seat and which can be removed for cleaning as required.    $295

Sun Mar Pint Flush

     Sun-Mar offers a selection of 1 pint flush toilets for use with regular Centrex 1000, 2000, and 3000 series central composting toilet systems. More than one "1 pint flush" toilet can be installed with these units if necessary. The constraint is the number of people using the toilets rather than the number of toilets. Using about one pint per flush, these ultra low flush toilets provide all the advantages of a flush toilet while minimizing water usage.

     They are ideal for use with Sun-Mar Central Composting Systems, but can also be used with holding tanks, overloaded septic systems, and in RV's. A simple foot pedal flush opens the water valve and gate when pushed down, and fills the bowl with water when lifted. After flushing, a small amount of water is held in the toilet bowl which is sealed by a self-cleaning ball valve and teflon seal. Even gravity-fed water from a roof tank is sufficient to flush a Sealand toilet. In winter they can be flushed manually, using a container if necessary.

     The Sealand 510 Plus has a regular sized toilet seat and is 2" longer and 1" wider than the Sealand 2010. In some instances extra height is needed to allow the toilet to gravity feed to the composting unit. Where this is the case, the Sealand 511 Plus (large bowl) or the Sealand 2011 (small bowl), low profile models with a 10" seat height, can be mounted on a platform.

     For Sun-Mar installations, we recommend the 510 Plus as the unit of choice as it has the size and appearance of a "regular" toilet. The 2010 is suitable if you have a very limited space in which to install the unit. Sealand toilets are available in either White or Bone. They come complete except for the required 3" four (4) bolt floor flange.

Sealand 510 Plus/Sealand 511 Plus $310