How Waterless Urinals Work
When selecting a waterless urinal for your business its very important that some consideration is spent on what is the appropriate model for your business.
Waterless Urinals and the options avaliable
This fact sheet describes the different design features of commonly available waterless urinals, and the things you should consider to make sure your waterless urinal installation is successful.
Conventional water-flushed urinals are water intensive. Multiple stalls connected to one flushing device use between five litres and 20 litres a flush. In somecommercial buildings urinals can account for up to 20 per cent of total water use –
and it’s estimated that they use about two per cent of Sydney’s drinking water.
Many conventional urinals are designed to flush automatically. This is usually achieved with a pre-set cyclical flush, a smart demand system or a motion sensor that detects when someone has used the urinal.
Urinals can waste water if they are set to flush continuously, if the radar/infra-red motion sensor malfunctions or if the motion detection sensor is activated by general bathroom traffic. Corrosion of solenoid valve seats can also cause leaks.
A single inefficient urinal in a high use location can use up to 700L/day, or 255 kL/year. Building owners pay sewer usage charges, meaning that they are also paying extra for wasted drinking water to be flushed straight down the drain.
Well maintained, single stall, smart demand or manual flush urinals are the most efficient type of conventional urinal. Waterless Urinal Supplies can assist you in installing one of our flush timers.
Waterless urinals have three main designs:
1. Barrier Liquid (either refillable or replaceable cartridge)
2. Mechanical designs
3. Microbial blocks.
Each design has different requirements for installation and maintenance, and offers different advantages and disadvantages.
How it works:
A refillable Barrier Liquid cartridge or trap creates a physical barrier between the user and the plumbing. Barrier Liquid traps are a variation of the standard plumbing ‘S’ trap. The Barrier liquid is lighter than water, including urine, and the barrier liquid layer prevents any odours from entering the room through the trap.
Physical barrier between user and plumbing system. Cartridge is easy to refill, improving
ease of maintenance and reducing costs and waste.
Cleaners and maintenance staff need to be trained to know when the cartridge needs replacement.
Seals may be lost if cleaners empty large volumes of water into the unit.
How they work:
One-way valves enable urine to pass into the plumbing system, but stop odours going back into the washroom. These are the newest type of waterless urinals.
Physical barrier between user and plumbing system.
Barrier will not break down with large water volumes that may be used by cleaners.
Mechanical design allows a wide range of cleaning products to be used
Some manufacturers give five year warranty on seals.
Relatively new on market so durability is less tested. Cleaners still need to be aware of
corrosive tendency of some cleaning agents on pipework. One way valves may still require
regular replacement of valves and seals.
How they work:
Bacteria are contained in
a water-soluble block (like a large sugar cube) that is placed in the urinal. The blocks are designed to break down on contact with urine to release odourmasking agents and bacteria that will break down the components of urine that cause scale and odour. A small amount of water is required each day to keep the bacteria active.
Can retrofit an existing urinal without expensive plumbing works or installing new urinals. Water ‘S’ trap is retained to create barrier between user and plumbing system.
Users report that microbial blocks work most effectively in single stall urinals because cleaning, maintenance and block placement can be better managed.
May cause odour in older urinals, especially if pipes are old, corroded or have scale build up. we recomend our “Deep clean service” to manage this issue. Sanitary flushing may still be required. (Flush timers offer a great solution for this)
Cleaning techniques need to be changed – common cleaning chemicals can harm the bacteria a waterless urinal bacterial cleaner is required for daily cleaning.
Blocks can break down and become trapped, causing urine to pool and create odour. (Our deep clean service will ensure this is not a problem)
A properly designed waterless urinal may save more water and be easier to maintain than a retrofitted traditional urinal. Newer waterless urinals will be more acceptable to users and cause less odour than older styles.
Issues to consider
The physical properties of urine can create problems for users and maintenance staff if waterless urinals aren’t installed properly. Urine contains urea, ammonia and other compounds of nitrogen as well as salts, phosphates and sulphates. Ammonia will corrode copper and copper alloys. In moist conditions, including those in urinals, ammonia rapidly attacks copper. This may lead to corrosion and stress cracking of sewer pipes. Copper pipes should be replaced with PVC pipes before installing waterless urinals.
Bacteria can precipitate calcium from human urine, causing a build up of hard calcium scale on urinals and plumbing fittings. This can increase if water does not frequently flush away urine. Allowing scale to build up can cause odours and reduce the capacity of your pipes. It can be a costly problem to fix, especially in older buildings where sewer pipes may be inaccessible, or their location unknown.
Because urine can cause scale build up it is also important to consider the age, design and condition of the sewer pipes servicing your urinal. It is important to confirm that sewer pipes have sufficient fall to allow urine to drain freely away without causing a build up of sludge or scale in pipes. It is recommended that the fall of pipes draining urinals should be at least two degrees, and preferably more. Bacteria can also cause chemical reactions and produce ammonia, which can be corrosive, and create a very unpleasant odour for users. In confined spaces a high level of ammonia gas may also present a health hazard. Older pipes may already have these problems, which will become more apparent when they are no longer being flushed with water.
To avoid odour, urinals should have a physical barrier between the plumbing system and the user, and ventilation should be high.
University of New South Wales
The university uses oil seal trap style urinals for new installations, and uses microbial blocks to retrofit existing urinals. The university also uses bore water forsome other toilet and urinal flushing. UNSW has estimated that using waterless urinals saves between 95 and 140kL of water for each urinal (or per metre of wall hung urinal) every year. Savings vary between the two different types of urinals and also depend on the how often the urinals are used.
To make sure that oil seal trap urinals are refilled often enough to avoid odours in extremely high use areas (near the university’s quadrangle), the university uses one maintenance contractor, whose service frequency depends on how often urinals are used in each building. UNSW has also discovered that installing privacyscreens between urinals helps to even out urinal use in washrooms, making it easier to schedule maintenance. The university has worked with microbial cube suppliers to produce multilingual training material after noting the importance of educating cleaners to avoid using strong disinfectants in these type of urinals.
Westfield trialled different brands and types of waterless urinals in several shopping centres across Australia. The urinals trialled included microbial cubes, mechanical and oil barrier designs. Westfield discovered that all four brands trialled had similar payback periods and that the oil barrier and mechanical barrier urinals used had the lowest ongoing maintenance costs. Westfield is now installing these two designs on an ongoing basis.
Before installing your waterless urinal, you should ensure:
The urinal is WaterMark approved you understand all the relevant technical standards and Australian Standards.
Current sewer pipes are not made of copper or a copper alloyn there is enough fall in the urinal to avoid urine pooling and odour.
The fall of the sewer pipes is sufficient (at least two degrees) to avoid the build up of scale and sludge in the pipes and that current sewer pipes are well cleaned and don’t have pre-existing blockages.
The area is effectively ventilated to prevent odour you have good sewer service diagrams and are confident that pipes leading from the urinal are accessible if you need to maintain them.
Cleaning staff implement regular cleaning regimes, and don’t use strong bleaches that may damage pipework or bio cubes when there’s no regular water flushing.
There is a physical barrier between the user and the sewer pipes. This may take the form of a proper seal in mechanical waterless urinal units, a properly maintained oil barrier, or retaining the water trap when retrofitting existing urinals with bio blocks.
Other water using facilities – such as showers or washbasins – are upstream of waterless urinals where possible. The flow of water should help to flush urine through the pipes, and avoid scale build up
Privacy screens are installed between individual urinals to help even out urinal use in washrooms, making it easier to schedule maintenance.