American Standard makes both the china and the flush valves, like this Selectronic model.

Electronic flush valve technology has come a long way in the 20-plus years that it has been available. There are more manufacturers today and early problems have largely been solved.
And while hands-free equipment has long been marketed for its hygiene benefits – the toilet or urinal is always flushed – today water conservation and LEED (Leadership in Energy and Environmental Design) standards are accelerating the shift to electronic flush valve technology.
“We see water savings being number one on just about everyone’s list of needs at the moment,” remarked Garry Scott, vice president, wholesale marketing and brand management, for Moen Canada in Oakville, Ont. And many engineers are designing to U.S. Environmental Protection Agency (EPA) WaterSense standards. Ontario adopted WaterSense labeling in March.

Better electronics

Today’s sophisticated electronics and sensors pinpoint the proximity of the user more accurately, reported Peter Ashton, commercial sales development manager for Masco Canada in Mississauga, Ont. Delta Faucet’s H2Optics, for example, use a form of triangulation to achieve this.
Technology has also largely cured the problem of the “phantom flush” caused by reflections off various surfaces, reported Bryon Keats, western Canada area manager for Zurn Canada. “Our engineers have updated the technology of the circuit boards and the sensors and added high impact lenses so we’ve cut out the majority if not all of the reflection.”
And self-adaptive sensors adapt to their own environment and reduce both installation time and errors, noted Dan Walker, installation and technical service manager for Dobbin Sales in Toronto, the master distributor for Sloan products in Canada.

Delta Commerical’s electronic flush valves sense duration and distance.

Water conservation

Manufacturers have dramatically reduced the amount of water per flush with electronic flush valves. Toilets flush as low as 1.28 litres while urinals are down to half a litre or less. This compares to 3.8 litres per flush (one U.S. gallon), the industry norm for low flush urinal valves.
Sophisticated electronics have also allowed the development of dual flush valves that can sense the duration and the distance the user is from the toilet to determine the appropriate flush. Most models work on duration, with a light flush if the user is in the stall less than 60 seconds and a full flush if they are in there longer.
“Compared to a manual flush valve, there’s about a 37 percent savings on water without sacrificing one ounce of performance,” remarked Scott.

A built-in solar cell extends battery life to seven years in the Sloan Solis Models

Installation and maintenance

Today’s flush valves are easy to install and virtually maintenance free once in place. They have to be durable because of the sheer number of people that may pass through a public washroom over the course of a day. Moen flush valves were recently specified for washrooms at Humber College in Toronto. “We were looking at rooms where we saw 20,000 individuals pass through on a daily basis,” reported Scott.
Flush valves today are diaphragm, piston and solenoid operated, with diaphragm models making up the majority. Traditionally, piston models were used in low water pressure situations. However, as technology progresses the distinction isn’t as clear – some diaphragm models can be used down to 15 psi or as high as 200 psi.
They are precision mechanical devices and any dirt or debris in the system will affect performance. Diaphragm models have a tiny orifice that allows water in the top chamber to pressurize and if it gets plugged the flush valve will run continuously, noted Keats.
While some, if not all, units have built in filter screens, it is critical to flush out the plumbing system, with diaphragms removed, prior to commissioning the flush valves. Manufacturers also recommend Y-strainers or some type of filtration on the main line(s) coming into the building.
Water pressure must be adequate. While some flush valves may work as low as five psi, manufacturers of vitreous china recommend at least 25 to 30 psi to properly evacuate the fixture. “(Adequate water pressure) is more critical to the bowl than it is to the valve,” noted Walker. “We find when we have issues with bowls that aren’t evacuating it’s because the pressure is falling well below 30 pounds.”
Flush valves are typically pre-set at the factory. Some models can be adjusted for flow and the electronics can be adjusted for the size of the stall. In fact American Standard offers a remote control that the contractor or maintenance person can use to adjust range and functions, reported Nunzio DiCesare, product support manager for American Standard Brands, Mississauga, Ont. Obviously, however, cranking up the flow to compensate for plumbing deficiencies defeats the purpose of installing low flow equipment.