Sensor Technology in Faucetry and Flushometers
As if by Magic
Back in the olden days, people used to have to grab onto a valve handle and give it a twist if they expected to get water out of a faucet. It was similar in toilet facilities too, as users would have to operate a handle of some sort to get the, uh … facility to do its bowl cleaning thing. Today, that kind of personal involvement isn’t required anymore, as some faucets and flushometers will do what they’re designed to do without any real personal effort on the part of the user.
And what’s behind the seemingly magical activation of some faucets and flushing equipment? Not magic, that’s for sure. Instead it’s electronics and science working in the bathroom to make all of our lives just a tad easier and more sanitary.
Mike Gipson is the product line manager for flushometers at the Sloan Valve Co., in Franklin Park, Ill., manufacturers of the G2 Optima Plus sensor-operated water closet flushometer. He said some of the first sensor-operated flushometers were developed in the late 1980s or so.
“The current version that Sloan has was developed in the early 2000s,” Gipson said. “Roughly 2003 is when the G2 Optima Plus was introduced. That is still alive and doing very well today.”
And, of course, the “magic” these devices employ to either turn on the water at the faucet or to flush the toilet or urinal is good old infrared — the same invisible light beams you probably use to change the channels on your television or to control some “radio-controlled” toys. The infrared sensors in the devices are electrically powered, either by being hard-wired into an electrical system as would be common in a remodel or new construction scenario, or battery-operated, which is common in many retrofit applications. That’s not to say other types of control couldn’t be used, it’s just that, today, these devices generally use infrared.
“As best we know, the market consists today of infrared,” Gipson said. “It’s active infrared. That’s the technology of choice. I think it’s really a combination of cost and performance. It’s not laser beam technology, but it’s a lot more affordable and still does a very nice job at a reasonable pricepoint.”
Things are similar on the faucetry side of the coin, according to Tony D’Amato, the product marketing manager, commercial fittings, at American Standard, the Piscataway, N.J.-based supplier of the Selectronic line of sensor-activated faucets and flush valves.
“To me, infrared is the main technology because it’s much more foolproof,” D’Amato said. “That’s why it’s used in all different products including flush valves.”
Flushometers and faucets work differently, though. With a faucet, your hands break the infrared beam, which signals the circuit board in the unit to turn the water on. It will continue to run as long as your hands are breaking the beam. Take them away and the water will shut off after a short period of time as long as nothing else breaks the infrared beam. Flushometer sensors, on the other hand, sense a presence but don’t actually actuate the flush until a short period of time after it can’t sense a presence anymore. The basic difference between the two activation schemes depends on what chips and circuits are on the control board.
“We actually have a multifunction sensor, so we’re able to use the same sensor in our faucets and our flush valves,” D’Amato said. “What we do at the factory is we program them. If it’s a faucet, we program it as a faucet with all the parameters that we would normally set in terms of what the range would be, which is the distance away from the sensor where it’ll detect someone. We program it to turn on as soon as it ‘sees’ someone. We program it to turn off maybe a second or a second and a half after someone leaves the front of the sensor so that the faucet doesn’t turn on and off really quickly.”
Gipson agreed, saying it’s all about the software that goes with the hardware: “The flushometer basically is always looking for what we call ‘valid targets.’ Just in case somebody walks by, it uses, in our case, an eight-second delay to make sure that it’s got a valid target. Then after the user leaves the range, there’s a two- to three-second delay, and then you get a flush.”
Sanitation or Conservation?
Early on, when sensor type faucetry came out, some were marketed as water-saving devices. And it can be true — a properly operating sensor faucet will shut off the water on its own. Things, as they have a way of doing, changed and now sensor-operated fixtures are more about sanitation.
Gipson said sensor operated fixtures are primarily about sanitation, particularly in commercial settings where user behaviors, “let’s just say, is a little more erratic.”
“The sensor is designed to make sure that the bowl gets flushed. That’s certainly a huge advantage,” he said. “At the same time, the flush volume of sensor activated flushometers, just like a manual, has continued to go downward, so we are saving water at the same time. In fact, we have several dual-flush models. The way that works is, if the user is in the range for a minute or less, it makes an assumption that you’ve just deposited liquid waste, if you will, so you can get by with reduced flush. On the other hand, if you’re there longer than a minute, it makes the other assumption and delivers a full flush to the flushometer. It takes all the guesswork out of the water savings aspect. There’s definitely a water savings aspect to the product. But I’d say, as you guessed, that sanitation, particularly in the commercial setting, is of more importance.”
D’Amato agreed, offering that people have been “up in the air” about the water-saving part of the equation.
“On the faucet, yes, if you have somebody who’s leaving the faucet on for a little while longer than the sensor faucet would be on, that could use a little bit more water. Or metering faucets — like the push button kind — a lot of those stay on for ten seconds whether you’re there or not, whereas a sensor faucet turns off as soon as you leave. But, it really is sanitation and that’s how we view it. Everybody compares the amount of germs on something to a toilet seat. Well, the toilet seat is actually extremely clean compared to a lot of other things in the bathroom including the faucet handle. The faucet handle has got more germs on it than the toilet seat and a lot of other things. Preventing someone from touching that handle is a good way to prevent germs from being transmitted from one person to another.”
Gipson said the sensor-operated flushometer portion of the market, at least, is a relatively small element of the overall picture, but they’re a great upgrade and something worth considering.
“I think [sensor-operated flushometers] are a great way to upgrade the restroom from a performance standpoint and an image standpoint. I think they look good. In some cases, if they’re behind the wall, if they’re concealed, they look even better,” he said. “Also, I would just say that, over the years, the technology continues to get better and better. Some of the shortcomings, maybe, when they were first introduced 20 or 30 years ago have been overcome and the technology improves. It’s a very solid product and one that we think makes a lot of sense in the commercial application.”