How it works
- Virtually all WC urinals in the UK operate using an automatic syphonic cistern. This means that they flush each time the cistern fills, often more than three times an hour, even when your building is unoccupied at night or closed for holidays. Most of this expensive water goes to waste.
- The Marnic Water Watch detects when the facility has been used. A PIR (Passive Infra-Red) sensor detects individuals using the urinals and triggers the filling of the cistern. The urinal then flushes in the normal way.
- The Water Watch knows how long it takes to fill the individual cistern and will time the flush so that not a drop of water is wasted. It can be programmed during installation to provide optimum flushing during periods of toilet use. The default setting is 20 minutes but other flush cycle lengths of 15, 30 or 60 minutes can be also selected.
- In addition to the normal flush setting, a 12- or 24-hour delay between detection and flushing can be selected to ensure that the urinal is flushed at least once or twice a day. This way the hygiene flush keeps the urinals clean and fresh even when the toilet is unoccupied..
Operation of the Traditional Syphonic Urinal Cistern
Virtually all WC urinals in the UK operate using an automatic syphonic cistern. This mechanism has no moving parts. It consists of a cistern mounted above the urinal basins. Inside the cistern is a syphon valve. The cistern is supplied with a continuous steady stream of water; the water flow rate is set by a petcock. When the level of water gets to a fixed point in the cistern, syphonic action starts and the contents of the cistern are rapidly “dumped” though the urinal basin feed-pipe, causing a flush. This flush cycle repeats continuously 24 hours a day. The number of flushes per hour is set by the flow rate of water to the cistern.
Operation of the Water Watch Intelligent Flush Control System
The Water Watch Intelligent Flush Control System comprises of a simple retrofit kit that can be installed to urinal toilets in 30-40 minutes.
It consists of a sensor and a water control valve.
The valve is fitted to the water inlet pipe prior to the petcock.
The sensor is fitted either on the wall or the ceiling, near the urinals where the Water Watch will detect use.
The installation engineer will set the cistern fill-time. This will vary from one cistern to another depending on size and the rate at which it fills. By setting the fill-time for each individual cistern, the flush cycle is calibrated precisely to the facility and optimum water savings can be achieved.
The delay is then set. This is the time between use of the facility and the flush. One of four can be selected; 15, 20, 30 or 60 minutes. The Water Watch is installed with a default delay of 20 minutes.
When occupancy is detected, an internal timer starts which counts down this preset delay. The Water Watch knows how long it takes to fill the cistern and tells the control valve to open at the exact time required so that when the timer has finished, this cistern is full and ready to flush.
If the facility is unused, for example, during the night or at weekends, a programmable 12- or 24-hour hygiene flush is initiated.