Imagine that you’re going to visit an aging relative who lives in a lushly landscaped retirement community. But wouldn’t you know it, you’ve managed to hit the day of the big lawn bowling tournament. You watch Aunt Emmie step up with her ball, get ready to make the winning throw, and then—the sprinklers come on.
The retirees scatter with ear-piercing screeches, soaked to the bone. The game is effectively over, no one’s had a chance to be declared winner, and the retirees are more than a little unhappy. Perhaps if their retirement community was using a central control system, this scenario could have been avoided.
It can be difficult to find times to give turf sufficient irrigation. Non-use times may be few and far between, and human error can result in a miscalculation that causes the sprinklers to come on at inappropriate times, or worse, not at all.
Central control systems can take the risk of human error out of the equation. Most can be given all sorts of watering restrictions, and still find ways to give landscapes the necessary irrigation. “Even if you’re on an odd/even day watering schedule, a central control system can recognize how a month with 31 days can cause a problem, and change schedules accordingly,” says Rain Bird’s Laurent Reinhardt. But what is central control?
Central control has been defined as the ability to program, monitor, and adjust a large irrigation system, sometimes with hundreds of stations, from one central location, usually a computer. “It was first used to manage the irrigation of golf courses. Now, a central control system can not only manage a single site, but also multiple sites spread over a geographic distance. All the data is sent to a central PC,” explains Brian Ries of The Toro Company, irrigation division.
A retirement community or large condominium complex can control the irrigation for its entire site with central control, from drip systems in flower beds to sprinklers on turf areas. This would be single site management. A school district, on the other hand, might use a central control system to handle irrigation at every individual school. A city’s Parks and Recreation Department could use a system to centrally-control irrigation for all of that city’s parks. This would be considered multiple site management.
Why central control?
“Central control is a huge tool for contractors,” says Steve Springer, vice president of business development for Rain Master, Simi Valley, California. “Say a company has been hired to maintain the properties in a homeowners’ association, or even multiple homeowners’ associations. When the weather gets hot, that company is going to have to send guys out in their trucks to run around to every residence and adjust the controllers. That can cost a significant amount of money—wages, insurance, gas, wear and tear on vehicles—as well as being a pain for employees. With a central control system, all of those properties can be managed from one location. Imagine the savings in gas alone.”
Another added perk: you could be working from inside an air-conditioned office instead of in 95° heat in the field. Furthermore, time spent driving or walking from one location to the next can be used for something more productive.
Evapotranspiration (ET) features have only recently become common on residential controllers, but some central control systems have had them for years. Many systems can communicate with an on-site weather station to receive daily weather data. The system can then automatically adjust irrigation schedules to give landscapes the right amount of water in various weather conditions—so the contractor doesn’t have the hassle of manually changing schedules with the weather. Once it’s set up, it’s all automatic.
ET calculations can also produce significant water savings for your client. “Many customers have reported 25 to 50 percent water savings using ET features,” says Reinhardt. “The return on investment is typically less than a year because of water savings,” adds Springer. Water-saving figures like these are good for you, too: if you can show potential clients how much water, and therefore money, you can save them with central control, you may be more likely to win the bid for a job in the first place.
A variety of self-diagnostic features are another boon to contractors. Most central control systems have flow sensors that can recognize high flow, low flow, and no flow situations. “If kids come by and kick off the sprinkler heads in the middle of the night because they like to see the fountains, the system can recognize it and shut down the appropriate valves,” says Hunter’s Dave Shoup.
If a system senses a problem like this, many not only take action to correct it, but also alert the contractor—they send an e-mail, page, or even text message telling him that something is wrong. You’re sometimes able to dispatch a crew to address the issue before the customer is even aware of it.
Many systems also monitor themselves electrically. They can detect short circuits and issue alerts if any are found. They can also learn how much current a valve typically draws. “A valve that’s suddenly started using more current than usual could be about to fail,” John Fordemwalt of Boise, Idaho’s Baseline says. “The system can warn you about that.”
In fact, a central control system can warn you whenever anything deviates from the “normal” range, be it an electrical problem, flow problem, etc. Troubleshooting becomes a much simpler task.
Central control systems are constructed very differently from each other. This isn’t to say that they’re installed differently (although they might be)—what this means is that the intelligence of the system rests in different places. There are three main types of system architecture—PC-based systems, satellite-based systems, and internet-based systems.
With a PC-based system, the central computer directly controls the controllers in the field, in real time. The computer tells a controller to turn a certain valve on, and then tells the controller when to turn it off. In this case, programming changes are primarily made in that air-conditioned office mentioned earlier.
In satellite-based systems, the intelligence of the system lies in the controllers themselves. The central computer may transmit schedules to the controllers, and call in the next day to make sure the controller ran them, but it’s the controller that’s actually responsible for turning valves off and on.
“The controllers are really smart,” says Shoup. “Each one can handle its own little schedules in its own little world. The central computer is a convenience, not a necessity.”
The controllers monitor and react to flow, while the central control software gathers reports and data, and gives alerts if anything out of the ordinary happens. “If a tech is out in the field and notices that a change needs to be made, he can make it at the controller in the field, and then pull the information back to the central computer later,” says Ries.
Rick Capitanio, vice president of sales for Calsense, Carlsbad, California, calls satellite-based systems “de-centralized central control.” “If I want to prove the value of the system, we can go down to a site and install a single, independent controller, without a central control computer,” he says. “When potential customers see the water savings a single controller can produce, they’ll often want the whole system, computer and all.”
Either a PC-based system or a satellite-based system can work with a remote control, to further ease the hassles associated with maintenance. If you’re out of the office and driving by the site, you can click a button on the remote to make sure everything’s working properly. If you’re in the field and have just finished a repair, you can do the same thing.
Some remote controls can plug directly into the face panel of any controller in the field; others can download information directly into the handset from a controller, simply by standing nearby. “They’re designed specifically for maintenance contractors,” Capitanio says. “You can drop a remote or get mud on it—it’s rugged.” A few manufacturers give you the benefit of a remote control without the remote control, giving you software that allows any cell phone to be used as a remote.
Taking the idea of “remote” control to a whole new level is the internet-based central control system. With a system like this, you can be on vacation sipping a daiquiri on a beach in Jamaica, and if you have a laptop with internet access, you can log on to see how an irrigation system you installed in Boston, Massachusetts, is doing.
“The management of utilities such as air conditioning and heat in buildings has been done off-site by professionals elsewhere in the city for years,” explains Larry Sarver, president of Tucor, Wexford, Pennsylvania. “An increasing amount of contractors wanted to manage irrigation that same way.”
Installing a system like this is a great way to distinguish you from the competition. You can get a report in the morning on your home computer about how the system is functioning, before you’ve even left the house for work. Not many contractors can say they have that kind of constant access.
The central computer and field controllers in PC- and satellite-based systems communicate a variety of ways—they might talk over phone lines, radio, Ethernet, cell phone networks, or even some combination of all of the above. This “communications infrastructure” isn’t necessarily difficult to set-up, but it’s a step that doesn’t exist with a web-based system, which communicates wirelessly over the Web.
This means that an internet-based central control system can replace old equipment without too much of a hassle, because you don’t have to run a bunch of new wire. Not having to run new wire also gives internet-based central control systems low start-up costs, helping make central control available to a wider variety of customers.
“We have combined internet technology with ET technology. When our iCentral web-based system is combined with the ZipET program, the system can use zip codes to grab local weather data from online, and then adjust irrigation schedules accordingly,” Springer says. “Even the most diligent landscape manager doesn’t have time to adjust an irrigation schedule on a day-to-day basis. With ZipET, there’s no need to—it’s all done automatically.”
The ease of a complex system
The one problem with all of this central control business: it can sound complicated. But don’t let the high-tech jargon intimidate you. Not only are central control systems designed to be user-friendly and easy to operate, most manufacturers have great training and support programs set up.
|Photo courtesy: Rain Bird|
Many central control systems have a map feature, which allows you to view a map of a property that lists every controller, valve, etc. For more information about a station or a controller, you simply click its icon on the map. Some systems even divide the map by zones, so you can see which zones are running on ET, and which are running on moisture sensors.
“Almost everything you’d need to do is handled in three screens,” says Ries, of Toro’s Sentinel central control system. This isn’t unusual—many manufacturers have tried to streamline central control as much as possible. Most of the features can be managed in three screens, two screens, or even one screen.
Many also offer support for the system, with everything from service call centers whose entire existence is devoted to helping contractors with central control, to in-field training, to the ability to dial into your system to remotely diagnose and fix problems. “If you’re at all familiar with basic Windows operations, you can use central control,” says Shoup.
“We’ve tried not only to make our central control system as simple as possible, but also our controllers,” explains Capitanio. “Our controllers have a very large display which allows you to read full sentences. We didn’t want to have to give contractors cryptic, abbreviated messages.” Like several other systems, it can also be operated in Spanish.While central control systems may be different than what you’re used to, with the variety of support and service options available, you’ll never have to go it alone. Plus, think how much gas you’ll save managing a sprawling property from a comfy office—or, with the right system, even from a Jacuzzi!