Transforming washrooms

Published:  16 December, 2007

Cistermiser, which is widely known for its device for controlling automatic flushing cisterns, has been thinking more widely about improving the functionality and water use of washrooms.

Washrooms are huge users of water, both for flushing toilets and urinals and by taps. Every visit to a motorway service station, airport, theatre etc. provides an opportunity to see a range of techniques to reduce water use — or no concern at all about the cost of water, its disposal and heating it.

Reduce consumption

One of the biggest users of water in commercial buildings is washrooms, particularly urinals, and Water Regulations require all new installations of automatic cisterns to be controlled to reduce their water consumption.

Cistermiser has been involved in reducing the volume of water used by urinals since 1976, even before Water Regulations required such measures, initially with its hydraulically operated systems. This concept controls the filling of an automatic cistern by passing a measured amount of water into it in response to changes in pressure in the pipework when a toilet is flushed or a tap is turned on.

Controlling the filling of a cistern in this way prevents it flushing every 20 minutes, 24 hours a day, seven days of the week — saving huge amounts of water.

Without such control, an automatic flushing cistern could use 9 litres of water every 20 minutes, 24 hours a day. That amounts to over 236 m3 a year, a figure which is generally accepted to be reduced by 80% by a flush controller — amounting to a saving of 189 m3 a year in both clean water and waste water down the drain. The payback on the installation of such a device is just six months, including installation costs.

Hands-free washroom

Cistermiser continued to confined itself to automatic flush control until it was taken over by Davidson Holdings in 2004. Research and development since then has led to the company devising new approaches to flush control and other products for the ‘hands-free’ washroom. The philosophy behind all these products, as described by managing director Geoffrey Gestetner, is to save water, promote hygiene and provide universal access.

There are three types of product.

• The first is sophisticated control of urinal flushing using water direct from the mains.
• The second is a no-touch dual-flush WC valve.
• The third is a hands-free basin spout.

All three types of product require electrical power, which can be provided by mains or a battery pack using standard alkaline AA batteries with a life of 160 000 cycles per battery set. Mains power can be provided by individual units or by a centralised unit that can serve up to 10 devices in a large washroom.

Direct Flush units for urinals use one valve per urinal and mains water for individual flushing rather than flushing in groups, further reducing water use. Qualification for Enhanced Capital Allowances reduces the payback on investment.

Individual infra-red sensors detect a user after 10 seconds and flush the urinal after use, not during. The flow is interrupted if the urinal is used again to avoid any risk of splashing.

Hygiene

cistermiser
Towards the automatic, hygienic and water-saving washroom — these products from Cistermiser use infrared sensors to control taps for handwashing WC flushing and urinal flushing.

A hygiene flush function ensures that the trap is kept full if a urinal is not used for long periods.

Direct Flush is suitable for use with siphonic traps by following a long flush with a short one to refill the trap.

Versions are available for surface mounting or installing behind panels, with only a small circular sensor showing.

Moving naturally on to the sink, the new Novatap also uses infra-red sensors, built into the tap itself, to provide hands-free operation. Hot water is delivered to the tap through a thermostatic mixing valve (TMV) and passes through a flow-limiting aerator to provide a soft-touch, splash-free water stream. Water is delivered for an adjustable period, which is factory preset at 2 seconds. Novatap qualifies for Enhanced Capital Allowances.

An important safety feature of Novatap is an automatic hygiene rinse to prevent water being static for too long between the TMV and the tap itself. The taps can be disabled while sinks are cleaned.

The third new Cistermiser product is the Easyflush hands-free dual-flush mechanism for WC cisterns. These mechanisms can be fitted into most cisterns, including retrofitting, and have sensors to suit. Simply passing a hand in front of the sensor activates a short flush, and a slight delay gives a longer flush. If preferred, the sensor can be mounted remotely from the cistern, for example, if it is concealed behind a panel.

A novel feature of Easyflush is being able to request a reflush, which is stored in the system’s memory so that a full flush is delivered when the cistern has refilled.

Automatic flushing can be over-ridden for cleaning purposes, and the cistern is automatically flushed every 12 hours.

Many settings of all three products can be controlled remotely using an infra-red configuration unit. One useful feature of this device is to provide a timed cleaning mode to disable their operation — individually, or all at once.

Vandalism

Despite the apparent sophistication of these products, Geoffrey Gestetner argues that they are even more relevant to schools and places that are prone to vandalism than to prestige applications. Equipment can be concealed, leaving only infra-red sensors on view, and vandalised taps simply stop delivering water.

He summarises, ‘We hope to see the universal adoption of the fully automatic washroom, with its attendant water and energy savings, as this would make the most significant contribution to the environment and an equally significant reduction in commercial operating costs.’

For more information on this story, click here:Dec 2007, 79

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