Carole Armstrong, Marketing Manager at Delabie, highlights technologies which can help to reduce water consumption in commercial washrooms.
Water is a precious resource. In developed countries, consumption per person has almost doubled over the last 30 years. The problem is exacerbated in non-domestic environments where users consume on average 200l per day. However, there are technologies available which can help to reduce water consumption in commercial washrooms.
Conventional wisdom suggests that showering consumes less water than taking a bath. Domestic showers allow the user to control the valve mechanism, so consumption depends on the user.
To prevent over-consumption, self-closing shower valves shut off the flow after a pre-determined time. Showering time can therefore be split into wetting, soaping, and rinsing. A self-closing shower prevents unnecessary waste, delivering up to 80% water savings compared to domestic showers.
Domestic showers provide maximum user comfort, but few are water-efficient. Installing a shower panel with a regulated flow rate in a sports pavilion, for example, can have a beneficial impact on consumption. A flow rate regulator will deliver 6l/min regardless of system pressure, whereas a flow rate limiter will only limit the flow rate.
Depending on the system pressure, a limiter may still be inefficient in high pressure conditions, and will exacerbate low pressure issues, causing user discomfort. Installing a single-feed shower panel with a regulated flow rate, fed by mixed water blended by a thermostatic mixing valve, can also reduce energy consumption. If less hot water is used, less energy is required to heat it, and the system design can reflect this.
Commercial washroom usage patterns are very different to domestic applications. Office washrooms see steady, regular use, whereas sports facilities face very intensive use followed by periods of inactivity. This has implications for water consumption and hygiene.
In public urinals, hygiene standards are maintained in two ways. The urinal is rinsed continuously to remove urine and maintain water levels in the trap, preventing unpleasant odours. This consumes significant volumes of water regardless of how busy the urinal is. Alternatively, an electronic sensor flushes the urinal bowl twice, when users arrive and when they leave. This is more efficient, but still wasteful during busy periods.
An electronic urinal with intelligent rinsing can detect high-frequency periods and adapt its rinse accordingly to prevent waste. For example, with the TEMPOMATIC 4 urinal, during peak periods, only the bowl is rinsed between two users.
After the busy period, an additional rinse occurs to clean the bowl completely and renew the water in the trap. The urinal valve offers three programmes according to the urinal type, each with an optional hygienic duty flush. The duty flush can be programmed to take place every 12 or 24 hours after the last use to flush the pipework and prevent the crystallisation of uric acid, water stagnation, and backflow due to system vacuums.
Preventing waste is just as important as minimising consumption in commercial applications. Thames Water estimates that a leaking toilet can waste up to 400l per day. The main culprit is the cistern. Designed for domestic use, the plastic components cannot withstand intensive use. The accumulation of scale and impurities affects the flushing system’s watertight seals. Unlike a basin tap where leaks can be detected instantly, a leak in a toilet is insidious and water streaming down the WC pan is difficult to detect.
In commercial toilets, direct flush technology will reduce waste, save water, and improve hygiene. The mechanism harnesses the system’s dynamic pressure to provide a powerful rinse. The flush is instantly available so there is no cistern refill time and no opportunity for water to stagnate or scale to build-up. Successive flushes are possible during busier periods, avoiding the problem of users trying to flush with a half-full cistern.
Dual flush systems are increasingly popular, however, the flush must guarantee a proper discharge of the waste water to avoid blockages. Direct flush WC valves are typically pre-set at 3-6l and can be adjusted to 2-4l to adapt to ecological or smaller children’s WC pans. The installer must ensure that the mechanism is robust, with no fragile plastic parts, and able to withstand intensive use in public toilets.
Saving water in commercial environments can be achieved in two ways; minimising waste and reducing consumption.