Let's Get Flexible: Irrigation Controllers

According to the U.S. Department of Commerce, 22 of the 23 fastest growing counties in the country are located in regions where landscaping requires irrigation to succeed. (Lawn & Landscape, November 1997, p. 51) The country’s population is moving to areas like Maricopa County, Ariz., Harris County, Texas, and Riverside County, Calif. This population shift translates into new landscape installation, which equates to a greater demand on the water supply in these areas.

So while contractors are being asked to maintain a greater amount of landscaped earth, they’re being expected to do so while using less irrigation.

Despite all of the advances in pop-up sprayheads, subsurface micro-irrigation and valves, perhaps no component of the irrigation system has the potential for having as significant of an effect on the amount of water wasted by irrigation systems as the system controllers.

WATER WATCHERS. When speaking to irrigation contractors about irrigation, water conservation is infallibly the first issue they speak about. And how that conservation can be aided by improved controllers usually isn’t far behind.

"The old, mechanical clocks are becoming obsolete as all of the manufacturers seem to have gone to the computerized, multiprogrammable clocks and that’s great," enthused Nick Bowen, sales manager and irrigation division manager, ILT Vignocchi, Wauconda, Ill. "Those old clocks only offered contractors one program, whereas the computerized controllers offer a number of programming options. As water continues to become a more precious commodity, we have smaller windows to irrigate in."

Bowen pointed out that, oftentimes, municipalities will enforce irrigation scheduling limitations that require increased flexibility on his part to irrigate all of his clients’ properties.

"Versatility in the controller clocks is a must, he asserted. In order to design a successful water management program, we have to be able to set up different areas to be irrigated at different times."

FLEX TIME. Keeping the landscape healthy and alive while minimizing water use requires innovative scheduling approaches on the part of irrigation contractors. Dealing with this challenge has motivated them to voice their needs for increased flexibility to manufacturers.

In addition, manufacturers must be sensitive to the needs of the end users of these systems, who are often homeowners with little irrigation knowledge.

"Residential controllers are a challenge for manufacturers, because who are you designing for?" questioned Joe Childers, controller product category manager, Irritrol Systems, Riverside, Calif. "There are certain features that are important to contractors that the homeowner doesn’t care about, such as how the field wires go into the controller."

"Features designed for the contractor are fine because the contractor can be trained to use them," observed Dirk Lenie, residential/commercial marketing manager, Toro Irrigation, Riverside, Calif., who added that too much complexity can make controllers unattractive to the homeowners.

Lenie noted that manufacturers really have four groups to consider when designing systems: "There are irrigation specifiers, who are looking for a lot of control features. Then the contractor is looking for no callbacks and ease of installation," he noted. "The municipal users are looking for maximum flexibility of control, and the homeowner wants reliability. The only thing everyone is looking for is low price."

One result of contractors’ flexibility demands has been the introduction by some manufacturers of modular-based controllers. "These are universal controllers for both residential and commercial projects," explained Jeff Carowitz, marketing manager, Hunter Industries Inc., San Marcos, Calif. "Contractors start with a base unit that is outfitted to operate eight stations. If the project eventually calls for more stations, contractors can plug in modules in four- or eight-station increments all the way up to a 48-station system."

The primary benefits of such a system to contractors, according to Carowitz, are that they will always have the correct size controller in stock and that they don’t have to purchase more stations than they need when purchasing a system. "For example, if contractors have a 19-station system, they don’t have to purchase a 24-station controller if they use modules," he noted.

In addition, modular systems can minimize the damage done by system failures. If a system controller fails, the contractor can simply replace the module that went bad instead of replacing the entire controller, Carowitz added. "We really think this is a revolutionary idea that will improve contractors’ ability to manage irrigation."

L.R. Nelson, Peoria, Ill., has also focused development efforts on the adaptability offered by controllers. Greg Natvig, electronics business unit manager, explained that the company has also introduced modularity to its controller line, while expanding its offerings to include commercial controllers with 36-zone capacities as well as residential controllers with 12-zone capacity.

"These types of controllers make a lot of sense for contractors because they allow for the potential of adding on to a system without having to keep as much inventory," he noted.

The other challenge controllers must solve is managing systems that have integrated multiple types of irrigation systems.

"A simple landscape with a simple program can be handled by a simple controller," observed Mario Larach, product manager for controllers, Rain Bird Sales, Azusa, Calif. "But landscape contractors and designers continue to get more creative, which means that controllers have to be more flexible."

"Controllers today have to be able to handle a diverse range of irrigation needs from drip to saturation," Larach continued.

WHY WIRE? One area of controllers that has really taken off, according to a couple of manufacturers, is the use of battery-operated controllers.

"These are controllers that mount on one valve or control a number of valves in the valve box," Larach noted. "This is opening up a lot of new avenues for irrigation that will go beyond the roadblocks contractors have been running into."

"The success we’ve had with our two battery-operated models has proven there are professional applications of battery power," he added. "We think that’s an entirely new market that’s just starting to emerge right now."

Natvig agreed, "We added a line of wireless irrigation control equipment that is battery operated, and it has been popular thus far. There’s a real niche application in the industry for these systems."

The key with the battery-powered controllers is that they allow contractors to take electrical power to areas that can be too cost prohibitive to wire for traditional power. In particular, Natvig noted that battery-powered controllers are useful for systems irrigating median strips that are surrounded by concrete.

"These controllers also help with retrofit applications for older systems that may have faulty wiring or a dead electrical system but good piping," Natvig continued.

Larach observed that battery power can make it easier and more affordable for contractors to expand a system’s capabilities. When there’s already a 12-station controller operating but the contractor needs to add another zone, these controllers let them expand the system without having to rip up the landscape or add a new line, he said.

The battery-powered controllers haven’t been immune to the push for greater flexibility from controllers overall, either.

"Right now, some of the more sophisticated control features aren’t available with battery-powered units," Natvig admitted. "But features like odd/even scheduling will be available in the future, and as new technologies come to market in the electronics industry, we’ll be able to adapt them to benefit the contractors even more."

In the case of automating older manual valves, Larach explained that contractors may be reluctant to trust battery-powered controllers because they utilize latching solenoids, but the electronics technology has improved enough to eliminate past problems. "A short pulse latches the solenoid, so there has always been the risk that if it latches open with water flowing and there’s not enough current left in the battery to turn it off, you’ll be stuck with constant water flow," he said. "Our controller has a mechanism built in so that the system won’t turn on unless there’s enough power left to turn it off."

"Battery-powered controllers used to have the reputation of being for homeowners or amateurs," Larach concluded, "but they’ve improved to handle the professional applications today."

Other manufacturers aren’t as high on the battery-powered units, however. "Battery-powered controllers are really hand-held valves," asserted Lenie. "There is an advantage to them in some specialty applications, but it can be a hassle to change the battery every year. Plus, reliability can be an issue since they go directly in the valve box where they can get wet."

SENSE & SENSOR-ABILITY. One area in which manufacturers can offer contractors increased control over irrigation systems is through the incorporation of rain and wind sensors with irrigation controllers.

"Rain sensors are a perfect example of a product that conserves water," commented Bowen. "We use a rain sensor on every system we install, including wind sensors for large, campus-type projects. I think the sensors should be a required part of irrigation controllers within the next five years and be hard wired into the clock, so contractors don’t have to combine two manufacturers’ products to use them."

David Klever, marketing director, Glen-Hilton Products, Richmond, Va., said the intensifying focus on minimizing water use has boosted interest in weather sensors.

"A study of two housing complexes with metered irrigation that started using rain sensors showed an average savings of 22,000 gallons of water in one year," he noted. "These sensors have the most value in areas with the greatest unpredictability of weather. In some areas, contractors generally know when it’s going to rain, and they can program their systems accordingly. But, in other areas where rainfall is less predictable, the sensors are a safeguard against operating a system while it’s raining."

While such sensors work hand-in-hand with irrigation controllers, the integration isn’t as perfect as manufacturers would like as of yet.

"Most of the rain and wind sensors that are on the market right now are what we call ‘passive sensors," Klever explained. "They don’t require the presence of electrical power to operate."

"The rain sensors, for example, have a dry contact switch that connects to the common line or sensor input terminal of the controller," he continued. "A disc in the rain sensor swells when it gets wet and will press on that contact switch and break the connection at a certain point. As it dries out, the disc recedes and the connection is re-established."

Klever said the primary challenge associated contractors and manufacturers face with using active sensors that use electrical power is finding a way to ensure long-term sensor operation when such electronics are exposed to the weather.

Meanwhile, Klever said he sees even bigger potential in the future.

"I foresee the development of an integrated irrigation controller in the future that allows the contractor to see exactly why a system has shut off and then reprograms itself," he remarked. "Currently, the controllers aren’t aware of the presence of the sensor unless there’s a dedicated input, and then the contractor can only see a flashing LED light saying the system was shut off for some reason."

In addition, Klever also expects to see sensors incorporated into systems through construction as part of the main controller circuitboard. "This construction would allow for the use of more active sensors because they would be much better protected from the elements."