Modern toilets fitted in cubicles are designed to effectively carry away waste whilst using as little water as possible.
The flush toilet is a technology that is potentially thousands of years old, but many of the most valuable innovations that make them cost-effective for operators and less wasteful of one of the most important substances in the world are somewhat more recent.
Thanks to several decades of innovations starting in the 1960s, the vast majority of washrooms, both in residential accommodations and in public venues will use technology designed to make the most of the water they need to function.
There are many different types of water-saving toilets, but the two main types that have seen use around the world are low-flush and dual flush toilets, both of which tackle the issue of minimising water use in very different ways.
One aims to make every flush use as little water as possible through the use of highly efficient systems, whilst the other provides the best overall approach that balances hygiene with water saving.
What Is A Low-Flush Toilet?
The low-flush toilet, also known as the high-efficiency toilet is not a single type of system per se but instead is a series of measures and technologies innovated in order to meet more stringent environmental requirements.
In the United States in the 1980s, the average flushing toilet needed at least 13 litres of water per flush (3.5 US gallons), and because they used floating valves often leaked even more water, making the toilets especially wasteful even at the time.
An increase in droughts and water shortages in a country that has historically suffered from regional droughts led to the development of a mandatory limit of six litres per flush (1.6 US gallons) for new toilets, to take effect starting in 1994.
Initially, low-flush toilets were made by modifying existing toilet systems using valves. The problem was that the water pressure was not sufficient to carry waste initially, almost leading to the law being repealed.
Eventually, the systems were made far more efficient, taking advantage of water pressure to push waste down rather than pull it as with a conventional water tank.
Low-flush toilet is a term typically limited to the United States, but most toilets opt to stick to the six-litre limit, only they go to even further lengths to save water.
What Is A Dual Flush Toilet?
A common but not ubiquitous toilet system in the UK but one that is almost universal in several other countries is the dual flush toilet, which true to the name has two types of flushes to handle solid and liquid waste.
Whilst these toilets are extremely popular now, that was not the case initially. They were first developed in 1960 by the Japanese company TOTO based on an extremely efficient system.
Not only were there two levers for the two types of flushes, but the TOTO system also had a built-in hand-washer. Any water that was used in the hand-washer would be reused for flushing.
However, whilst TOTO would have much greater success with the Washlet, a toilet with an integrated bidet, the initial dual flush toilet was too complex to be affordable for many residential or commercial customers, and sold very poorly.
The idea would disappear for two decades before it would be revived on the other side of the world, which led to one of the most curious quirks in the recent history of toilet design.
Caroma, an Australian developer of toilets and sanitary furniture, designed the first dual flush toilets, initially with an 11-litre flush for solid waste and a 5.5-litre one for liquid waste. Later innovations cut this water use nearly in half.
Because an Australian company innovated this system, when it became popular around the world, they borrowed heavily from the original design.
This included the flush controls, which unlike the lever commonly used in the United Kingdom and many other countries, consisted of a button that for the dual flush was split in half; the small button dealt with liquid waste and the large button handled solid waste.
This was an evolution of the Australian flush toilet, which used a button on the top of the cistern and relied on gravity to remove waste rather than using a siphon-flush system.
There are alternatives available; many public toilets use two buttons embedded into the wall, whilst others use a lever that is either depressed normally for a smaller flush or held down for a larger one.
Not all dual flush toilets are low-flush, and vice versa. However, the concepts do often overlap, particularly when it comes to toilets that emphasise water saving.
Related Posts
