Single vault UDDTs with a single vault have interchangeable containers to collect the fecal material. Depending on the size of the vault, two or more containers can be stored inside. Containers should be limited to a maximum volume of approximately 50 litres, so that they still can be manually moved when they fill up. Once a container is full, it can be left for further dehydration or removed for further treatment. Removal of the container requires care due to fresh, potentially pathogen-loaded feces being on top of the pile in the container. Because of the limited ventilation within a plastic bucket, such single-vault UDDTs may not reduce the pathogen load as effectively as double-vault UDDTs. Therefore, a post-treatment of the fecal material is usually required. This can be achieved through further dehydration, composting processes or heat treatments. On the other hand, if the container is made from a material that has a high permeability with air, such as woven sacks or baskets, then the drying performance in single vault UDDTs may be similar to that of double vault UDDTs. Double vault Double-vault UDDTs are alternatively called twin-vault, two-vault or two-chambered UDDTs. In double-vault UDDTs, the fecal material dehydrates in situ. The two above-ground vaults are used alternately. While one vault is filling up, the other (full) one stores the fecal material under dry conditions for at least six months. During this resting period, no fresh feces are allowed to enter the full vault. In order to switch from one vault to the other, the user interface can either be switched or both vaults can be equipped with fixed seats and a cover sufficient to prevent access to the full vault. When the second vault becomes full and at least 6 months have passed, the first vault is emptied with a shovel and then the user interface is moved over accordingly. The vaults are commonly sized so that one vault fills up in six to 12 months. Other (portable, mobile) Example of a portable (mobile) UDDT constructed out of molded plastic at a household in Vermont, U.S. Other types of UDDTs exist which are essentially variations of the single-vault type, but which are more self-contained, sometimes referred to as portable, mobile or stand-alone units and identifiable by their one-piece molded plastic shells or, in the case of DIY versions, simple plywood box construction. Most users of self-contained UDDTs rely upon a post-treatment process to ensure pathogen reduction. This post-treatment may consist of long-term storage or addition to an existing or purpose-built compost pile or some combination thereof. A post-treatment step is unnecessary in the case of very modest seasonal use. Mobile UDDTs are typically either fabricated of new materials in a factory or workshop using a mix of proprietary and off-the-shelf parts—and then sold to the public either directly or via distributors or retail outlets; or fabricated at home out of wood, using new and re-purposed parts and materials. They are typically compact and lightweight, allowing one person to easily lift, transport, and maneuver them into place. Likewise, installation is a relatively simple process given that everything needed for the proper functioning of the<unk> , except a source of electrical power for those models that include a fan and some allowance for exterior ventilation, is contained within the molded or wooden carcass. One advantage of this type of UDDT is that they are portable, making them an interesting option for remote or temporary installations and for installations aboard moving vehicles or non-stationary residences such as boats, recreational-vehicles (i.e. caravan, camper van, motor home) and tiny-houses. Features common to this type of UDDT include: * a smooth, easy-to-clean exterior surface * a molded seat with a cover (both or either sometimes fitted with a rubber or neoprene gasket to further assist in isolating the<unk> 's inner workings) * a molded<unk>  diversion bowl (or bucket and funnel assembly) to facilitate the separate collection and storage in separate containers of<unk>  and feces (the containers consisting of either a proprietary design or, in the case of DIY versions, readily-available or re-purposed buckets, bottles or jugs) * some allowance for either passive or active mechanical ventilation either consisting of a screened or filtered air inlet and a screened or filtered exhaust outlet (the latter consisting of a standard fitting to allow hook-up to a length of piping or tubing that is connected to the outdoors). Features unique to some designs include: * cleats for fastening the<unk>  to the floor (particularly useful when the<unk>  is installed in a moving vehicle or non-stationary residence) * spill-proof<unk>  storage to aid in leak-prevention during stormy weather or when otherwise underway (as in a moving boat or RV) * built-in agitator for mixing and aerating the contents of the feces container (which greatly aids in drying and odor prevention) * automatically or manually deployed pivoting or hinged trap door for covering the feces container when not in use.
Urine-diverting dry toilet
Composting toilet
Urinary catheterization
Transanal irrigation
Dry toilet
Management of dehydration
Oral rehydration therapy
Bladder training