How to carry out a urinal flow reduction
How to carry out urinal flow reduction
Automatic flushing of urinals when they are not being used can cause a significant amount of water to be wasted, although it is usually cheap and easy to stop. There are many possible solutions, such as infrared control, which can pay for themselves within months. Before deciding whether it is necessary to install new systems, follow our do-it-yourself guide to reducing urinal water use.
Here is a common 3.75 litre urinal cistern that provides flush water to two urinals. This urinal was found to be flushing 5 times per hour, that’s over 18 litres an hour.
Water Regulations state that urinals should use no more than 7.5 litres per urinal bowl for a cistern serving two or more urinals (10 litres per urinal bowl for a cistern serving a single urinal) per hour. For example, a 3.75 litre cistern supplying two urinals should flush each bowl no more than twice an hour.
To decrease the number of flushes you can reduce the flow of water entering the cistern. This is done by taking a screwdriver and turning the valve anti-clockwise.
As there are different makes and sizes of cisterns, trial and error is the only way to see how quickly your cistern fills up. For the 3.75 litre cistern a flow similar to this picture is a good place to start.
In addition to these simple measures, further savings can be achieved by investing in flush control systems – these either use a timer to match flushing to the hours of use or detect the presence of people.