Kimberley started installing self-composting toilets in 2014 with an integrated ventilation system in Kimberley Karavans. Self-composting toilets are very successful in boats but relatively new to caravans and camper trailers.
In the 3 years since the first instalation, users have overwhelmingly given strong positive feedback: "it is the biggest change for cleaner and easier camping - no need for a dump point and no added weight".
The benefits of self composting toilets:
The waterless toilet works by
This is a "game changer" in camping. Kimberley have designed the highest performance waterless toilet to give a longer life and easier wate removal.
See video on Toilet here:
Design changes for higher temperature
The two primary factors that destroys pathogens in the compost are temperature and time. A compost pile that is properly managed will destroy pathogens with the heat it generates. The higher the temperature, the faster the pathogens are destroyed and "happy campers".
This is the relationship of the internal compost temperature and time. This is NOT the ambient temperature.
“Complete pathogen destruction is guaranteed by arriving at an internal compost temperature of 62° C for one hour, 50° C for one day, 46° C for one week or 43° C for one month. It appears that no excreted pathogen can survive a temperature of 65° C for more than a few minutes.”
So we set our design target to get an internal temperature as close as we could to 65° C.
The Kimberley Kruiser already had a system for added heat:
Air from the drying chalet passes onto the composting toilet and is vented out through the roof. This will heat the base of the toilet. Together with a good aerorobic process the thermophilic temperature will increase to the maximum of 65 degrees C. As you can see from the chart, at this temperature, pathogens are destroyed in just over an hour.
For general use with Kampers and Karavans and Kruisers without running the drying chalet, a different heating system is required.
An independent 12V membrane heater has been designed to increase the internal temperature of the toilet.
The membrane heater is 25W. (using 2 Amps approx.) 4 hours use generates 100W of heat and uses 8 amp hours of battery capacity.
This accelerates the composting process just before emptying or in ambient temperatures below 20 degrees c.
Image shows cut away design and the removable liner.
How you use the waterless toilet:
When solids compartment is full:
After last use:
The last word in composting toilets critical in getting the best performance:
“A thermophilic (high temperature) compost pile will destroy pathogens, including worm eggs, quickly, possibly in a matter of minutes. Lower temperatures require longer periods of time, possibly hours, days, weeks, or months, to effectively destroy pathogens.”
"Although one need not strive for extremely high temperatures such as 65°C in a compost pile to feel confident about the destruction of pathogens, a higher temperature will shorten the time."
Read about the details in this handbook by clicking: