- The history of the dry closet
- Device, principle of operation and characteristics of peat dry closet
- Chemical toilet
- Electric toilet
- Criteria for choosing a dry closet
In this Article: The History of the Dry Toilet device and principle of operation of a peat dry closet; characteristics of a portable chemical toilet; description and characteristics of the electric toilet; criteria for choosing a portable dry closet.
Heading to the dacha with family or in a company of friends, we are ready to endure some inconveniences, such as possible interruptions in electricity and water supply, lack of hot water supply and natural gas – but what nature, what air! And yet there is one element of “urban comfort”, which one does not want to refuse – a toilet stall, and not like a dacha “birdhouse”, but a real one, with a toilet bowl and a drain. However, the solution to this issue rests on the complete absence of sewer communications in the bosom of nature – what can be done? There is a way out – a dry closet, outwardly similar to the usual plumbing of city apartments and does not need a sewage system.
The history of the dry closet
The prototype of the first dry closet was developed in the 19th century by the English priest Henry Mole. In the period from 1849 to 1854, another cholera epidemic raged on the territory of England and Henry Mole, seeing the suffering of his parishioners, decided to find a way to safely dispose of the products of human life. After several years of searching, he discovered that crushed peat was capable of converting organic waste into compost and, according to the results of research, created the first dry closet, receiving a patent for his invention in 1873. The design of Henry Mole’s dry closet – a wooden chair with a round opening in the seat, a bucket under it, a conical peat bin with a manual dispenser on the back of the chair – looks extremely primitive today, but 150 years ago it was the greatest breakthrough in plumbing. Mole called his invention “dry land” and, it should be noted, the demand for “dry land” in England in the 19th century was quite high – many hospitals, military camps and private homes in the countries of the British Empire were equipped with this device.
Henry Mole’s first dry closet
A hundred years after the dry closet invented by Henry Mole, the Swiss engineer and inventor Hardy Sandberg was faced with the problem of waste disposal in his cottage – he was not satisfied with the solution with a cesspool or septic tank. After several unsuccessful attempts, he came to the conclusion that it was necessary to entrust the solution of the problem to nature itself, providing it with only a little help. So in 1971 he created and patented the first portable dry closet equipped with a chamber for evaporation of liquid and a rotating drum, into which crushed peat was fed, with a drive from the front door to the toilet stall. The resulting dry compost was collected in a special drawer located next to the front door to the toilet stall. Founded by Hardy Sandberg, Sun-Mar Corp. is a manufacturer of dry closets and composting systems for human waste products that still exist today..
Hardy Sandberg toilet device
In addition to dry closets, the principle of which is based on the formation of compost from waste under the influence of crushed peat, there are models that are incorrectly attributed to this group – chemical and electric toilets. The first samples of chemical toilets were created in the 60s of the last century for the needs of aviation and are still used on all civil and military aircraft, antiseptic chemicals (glutaraldehyde and quaternary ammonium compounds) are used in them to deodorize waste during the entire storage period in the storage bin … Electric toilets dry and burn organic materials to ash.
Device, principle of operation and characteristics of peat dry closet
Any peat (composting) dry closet consists of the following basic elements: storage reactor for biological waste; ventilation (exhaust) pipe. As a rule, the body of the toilet bowl of the dry closet and the storage reactor is made of plastic, the weight of portable models in an empty state is about 15 kg.
The principle of operation of peat dry closets is based on the ability of a peat mixture to absorb liquid (1 kg of peat absorbs 10 liters of liquid) and the activity of bacteria that convert waste into compost or its semi-finished product. Flush water, which we are accustomed to in ordinary bathrooms, is not used in most compost dry closets. The processing of waste into compost is carried out by aerobic thermophilic bacteria contained in the peat mixture.
There are the following types of peat (composting) dry closets:
- single-chamber, with a storage container with a capacity of 2 m3 (the cost is about 70,000 rubles). The inner space of such a container is divided by an inclined panel, liquid waste is removed from the container by a diaphragm pump, solid, converted into compost, is removed by a screw pump;
- with a carousel-type hopper (cost about 37,000 rubles), divided into several compost chambers. As one chamber accumulates, the hopper rotates in a circle (horizontally), substituting an empty chamber under the seat. Dry closets with a carousel bunker take up more space than single-chamber ones;
- with a drum hopper (cost about 60,000 rubles). The aerobic process of composting in dry closets of this design takes place in a bunker rotating vertically – after visiting the toilet, you need to turn the handle of the drum several times, mixing the waste. At the same time, partially composted waste goes into a special container, from where it should be transferred to a compost heap, the liquid is discharged into a special container. The advantage of dry-type toilets is that the bunker and the toilet are located in the same body, i.e. no need for a warm underground container. Their disadvantage is that the waste content in the bunker is insufficient for the formation of compost, it requires ripening in the compost heap;
- dry closets with separate liquid outlet (cost about 23,000 rubles). The principle of operation is based on the separation of solid waste from liquid waste at the stage of collection; for this, their toilet bowl is equipped with an additional hole through which the liquid enters a separate storage tank, from which it evaporates, or liquid waste is discharged into the wastewater system. Solid and liquid waste enters the bunker either under the action of gravity or washed away with water under the influence of a vacuum system – no more than 1 liter of water is needed for solid waste and no more than 0.2 liters for liquid waste. The advantages of such dry closets are that the accumulated organic waste and toilet paper are dried by a fan, so the containers are changed no more than once every two months. Disadvantages – the need for electricity, regardless of the purpose of visiting such a toilet, visitors of both sexes must sit on the toilet seat, i.e. standing up to use it will not work.
Portable peat dry closets, as a rule, are equipped with forced ventilation, a mixture of peat and sawdust is contained in a storage hopper or, in simpler and cheaper models that are not equipped with a mixing system, in a hopper for peat mixture (located in the place of the cistern of a conventional toilet), equipped with a controlled manually by the flap. Removal of excess liquid is carried out at the expense of a membrane-type hopper, separate waste collection, a drainage system that removes excess liquid from a common storage hopper, due to an evaporation-heating system (heating elements) and automatic mixers mixing biomass.
Positive characteristics of peat dry closets:
- process organic matter into environmentally friendly compost;
- do not need water;
- lack of odors;
- depending on the model, the tank is cleaned, with the correct choice of its volume, no more than once every two months;
- as a result of the activity of aerobic bacteria, waste is converted into environmentally friendly compost, and any pathogens die in this case;
- low cost of a dry closet (depending on the complexity of the model device) – from 5,000 rubles;
- inexpensive consumables – a ready-made mixture of peat and sawdust will cost 5 rubles. per liter of volume.
- the construction of an exhaust system is mandatory, forced ventilation is required;
- separate drainage of liquids implies the device of a drain system or the presence of an electric dryer;
- the process of processing waste into compost is possible only at positive temperatures, i.e. installation of peat dry closets is carried out only in heated rooms or they are used only in the warm season;
- after installation, changing the location is difficult, since when moving, you will have to build ventilation systems again;
- lack of drain makes it difficult to completely clean the toilet;
- large overall dimensions (due to the ventilation system), compared to chemical toilets;
- significant weight of the filled container (depending on its volume), the need for periodic emptying.
On the Russian market there are domestic peat dry closets – “Elite” (LLC “Tandem”), “Lux M” (LLC “Magistral”), etc. – and imported products – Swedish companies “Separett” and “Biolet”, Canadian “Sun-Mar”, Finnish “EuroMakki”, “Green Toilet” and “Biolan”, etc..
Portable chemical toilets were originally developed for campers (summer caravans), then their convenience was appreciated by the owners of yachts and hunting lodges. The design of chemical toilets includes two detachable bins located one above the other – the upper one is equipped with a toilet bowl and filled with water (volume 10-15 liters), the lower bunker contains chemicals (reagents) and is designed to collect biological waste. Most often, chemical toilets are cubic in shape, their height is 320-420 mm, depending on the volume of the lower hopper – by the way, its volume can be from 12 to 24 liters. In addition to models with one receiving hopper, there are models with a cassette-type hopper, mechanically similar to a peat cassette dry closet – the cost of such a chemical toilet is about 18,000 rubles.
The principle of operation is simple – the waste is washed off with a manual or electric water pump and enters the lower hopper, liquefies during chemical treatment and, after filling the hopper, is poured into the sewer system. Chemical preparations destroy any microorganisms, odors are blocked by a specially designed valve.
Positive characteristics of chemical toilets:
- compact and mobile, can be repeatedly moved from one room to another;
- complete absence of the need for connection to external communication networks, with the exception of models equipped with electrical appliances (pump, sensors for filling the lower hopper, etc.);
- the installation does not require any special skills – set it up, fill the upper tank with water, the lower one with a reagent and use it;
- temperature differences do not affect performance in any way. Installation is allowed in both heated and unheated rooms;
- the weight of the structure with empty bins does not exceed 5 kg;
- low cost – from 4,000 rubles.
- needs frequent emptying of the lower hopper. The approximate frequency of emptying is every 25-30 visits for a 12 L bin, 50-55 visits for a 24 L bin;
- the cubic shape makes it difficult for different age groups to use the high chemical toilet. More precisely, a height of 320 mm will be comfortable for a child and inconvenient for an adult, in the case of a toilet with a height of 420 mm – the opposite is true;
- the large volume of the lower hopper is convenient for multiple users and inconvenient for emptying. The weight of a filled 12 l bunker will be about 14 kg, the weight of a 24 l bunker will be about 28 kg;
- constant need for a chemical reagent in liquid or granular form – an average consumption of 35 ml of reagent per 1.5 liters of water. The cost of the reagent is about 500 rubles. per liter;
- emptying the contents of the lower hopper into the soil will cause soil contamination. It should be noted that some manufacturers of reagents for chemical toilets declare that their preparations are harmless for soil microorganisms, but there is no complete certainty about this. Even if the waste is harmless, it must be pre-processed into fertilizer in the compost heap.
There are no domestic manufacturers of portable chemical toilets, the Russian market in this segment is mainly represented by the products of Thetford (USA) and Porta Potti (Italy).
The design of the electric toilet includes a plastic toilet bowl and two receiving bins, independent of each other – the first is intended only for solid waste, the second is designed only for liquid waste. Models are produced, both designed for the discharge of liquid waste into the sewer or drainage system, and for their complete evaporation. Dry waste is completely dried to a powder state using a compressor built into the toilet bowl. All models of electric toilets are designed for separate intake of solid and liquid waste – they are equipped with two inlets, respectively, you can use such a toilet regardless of the floor only in a sitting position. Removal of odors is carried out using forced ventilation.
Positive characteristics of the electric toilet:
- does not need any preparations of natural or chemical origin, i.e. environmentally friendly;
- the dried organic material is brought to a powder state, which significantly reduces the frequency of emptying the receiving hopper (1-2 times per year);
- no water required for flushing;
- complete absence of odors (due to forced extraction).
- the need for constant power supply, i.e. in his absence, you cannot use the toilet;
- stationary installation, mandatory need for forced draft;
- certain inconveniences of use associated with the separate receipt of waste;
- high cost, about 35,000 rubles.
Electric toilets from the Swedish companies Biolet (brand Cinderella) and Separett (brand Villa) are presented on the Russian market.
Criteria for choosing a dry closet
Regarding the principle of action of the dry closet – peat, chemical or electric – and the varieties of their models, then each summer resident must answer this question himself. It will be important to pay attention to the capacity of the receiving bunker, based on the number of inhabitants of the dacha, but here you also need to take into account that the large-capacity bunker is quite difficult to move for emptying due to its considerable weight, especially for chemical toilets. And you need to decide before buying where to dump waste from the bunker – with a peat dry closet it is easier, with a chemical one, everything is much more complicated..
Having decided on the principle of operation and the size of the hopper, study the following technical characteristics of the models:
- Toilet bowl height. As mentioned above, too low a toilet will be uncomfortable for adults, too high for children.
- The presence of an indicator for filling the bunker. Such an indicator will allow you not to keep a strict record of visits to the dry closet and will inform you when the bunker needs to be emptied.
- How the water flush system works (if available). Dry closets can be equipped with an electric pump, pump or piston pump. The electric pump simplifies flushing, but requires a mains power supply, rechargeable batteries or batteries. The principle of operation of the pump is similar to the siphon system of conventional toilets connected to the sewer – it is activated by pressing and acts as a result of pump pressure, preventing a metered flow of water. A piston pump, like any other, must be pumped manually – it allows you to meter the water flow, but it will be difficult for a child to use it, because the pump requires some effort.