The larger the compost tank is, the greater is its usage capacity. However selection of the most appropriate Clivus Multrum model is dependent on several factors:
- average and peak usage rates
- the number of pedestals required
- climate and site installation characteristics
For domestic use the smallest and most popular model is the CM8, suitable for households of up to 5 persons. The slightly wider CM10 will readily accommodate 2 pedestals, as do the larger CM14 and CM20. Where the available height under the floor is limited, the CM14 offers the lowest profile if the tank can be partially buried.
In public use facilities, all models have proven successful when generously sized
for the projected use. This approach allows for high peak loadings and for future
growth in patronage, and reduces the frequency of required servicing.
| Model | Uses/Year | Applications | Dimensions (mm) | Other |
| CM8 | 8,000 | Small homes, holiday houses, walking trails, remote work stations. |
Height = 1100
Length= 1550 Width = 1250 |
Min. clearance under floor = 1000
Max. buried in ground at front = 200 Max. fixtures - 1 pedestal |
| CM10 | 10,000 | Family homes with more than one toilet, small public facilities. |
Height = 1100
Length= 1550 Width = 1560 |
Min. clearance under floor = 1000 Max. buried in ground at front = 200 Max. fixtures - 2 pedestal |
| CM14 | 14,000 | Large sized family homes with more than one toilet, small public facilities. |
Height = 1100
Length= 2050 Width = 1500 |
Min. clearance under floor = 750
Max. buried in ground at front = 450 Max. fixtures - 2 pedestal |
| CM20 | 20,000 | Larger homes with more than one toilet, small to medium sized public facilities. | Height = 1630
Length= 2390 Width = 1200 |
Min. clearance under floor = 1400
Max. buried in ground at front = 300 Max. fixtures - 2 pedestal & 1 urinal |
| CM40 | 40,000 | Larger public and commercial facilities, e.g. Roadside stops and National Parks. |
Height = 1780
Length= 2430 Width = 1890 |
Min. clearance under floor = 1700
Max. buried in ground at front = 300 Max. fixtures - 4 pedestal & 2 urinals |
| CM60 | 60,000 | High public usage areas, e.g. Tourist stops, camping areas. |
Height = 2480
Length= 2430 Width = 1890 |
Min. clearance under floor = 2400
Max. buried in ground at front = 300 Max. fixtures - 4 pedestal & 2 urinals |
When planning to install a Clivus into a dwelling there are a few things to take into account.
Is more than one toilet required?
Toilet rooms that are side by side can usually be served by the one compost
chamber, although with the CM8 there is less flexibility. As the toilet pedestals are
connected by vertical chutes to the compost tank, pedestals that are some
distance apart will need a separate tank each.
Is there access beneath the toilet room?
Because the compost tank must be positioned under the toilet room, there needs
to be access to this area. On a sloping site, partial excavation as shown can be used to obtain the clearances needed to install and service the tank. Alternatively, a cellar or retaining walls can be built.
Locating the tank adjacent to an exterior wall can make access easier for servicing it.
Does the ground slope away so the excess liquid can be removed?
It is important that the tank always has good drainage and does not flood from
surface water or with rising ground water. The drain pipe for excess liquid from
the tank must slope down to its discharge point into a soakage trench or other
disposal method.
The volume of excess liquid will depend on several factors, but should not exceed 1 litre per person per day. In domestic installations there is frequently no excess liquid at all. Clivus Multrum can also provide reliable pump-out systems if natural drainage cannot be achieved.
Can toilets on the first and second story of my house connect into the one
compost chamber?
Yes, but the chutes must be vertical. Extra lengths of chute will be necessary for
the second floor toilet and a longer ventilation pipe will be needed.
The Clivus Multrum is designed so that the ventilation system draws air in through the compost tank and also down the toilet chute whenever the seat is lifted. This keeps odours out of the toilet room and makes the use of a separate room exhaust fan unnecessary. A small, heavy duty electric fan is installed in the vent pipe in a special housing that gives easy access for cleaning or replacement.
On request a wind driven turbo-ventilator can be supplied instead of the standard rain cover. This provides back-up to the vent fan especially when choosing the Daytime Solar option.
There are three fan options normally available:
- Standard 12V (5 Watt) heavy duty fan.
- A 12V (2.5 Watt) fan for low-budget solar installations.
- A 240V fan for high use commercial installations.
