While each jobsite will present its own unique challenges, there are some universal qualities that make either spray heads or rotor heads the advantageous choice in certain locations and conditions.
“The fundamentals and the principles behind the design are still the same as they were when I took design classes years ago,” says Pete Diebolt, president of Diebolt Landscape in Mohnton, Pennsylvania. “The products are addressing all of that. Most of the changes over the years have been with the control systems and some of the heads.”
The system design accounts for environmental conditions like wind or shade, elevation changes, the square footage of the area to be watered, and more. From there, choosing between a rotor head and a spray head comes down to a few other factors.
“The type of head that you use is dictated by the design because the heads are going to have all different lengths of throw and uniformity coefficient. The distribution pattern, wind, slope and other design factors would have a bearing on the size nozzle and how to program the zones to run,” Diebolt says.
Generally, rotor heads are the better choice for larger areas of turf. They have a low precipitation rate, so they will evenly cover more area over a longer period of time. This is ideal for sloped areas because it allows more time for water absorption. The head itself will also be larger and provide more coverage than a spray head, Diebolt says.
“The coverage might be three or four times the square footage. Labor savings is incredible,” he says.
Rotor installation may take a little longer than spray heads because their ultimate positioning is not immediately evident, says Justin Moseley, irrigation manager for Nelson Landscaping in Edmond, Oklahoma.
“You have to set them and then recheck them after they are installed, whereas with pop-up sprays, once I flush them out, I can set a nozzle and know which way it’s going to spray. Be it a fixed or adjustable nozzle, I can set it where I don’t even have to have water running through it to be set, whereas rotors need a little more fine-tuning,” Moseley says.
They are also spaced further apart, so the material cost can be a little more than what a spray head would be, Diebolt says.
Spray heads are designed for smaller areas and disperse more water in a shorter amount of time. This makes them a good choice for areas close to buildings, patios or other hardscaping on site that is not intended to get wet.
“For flower beds, we use nothing but pop-up spray heads. If it’s a smaller area, from 8-20 feet, we are doing spray heads,” Moseley says.
Spray heads typically require more maintenance than rotors because they are more prone to clogging, Moseley says.
“In Oklahoma, we have hard water that causes calcium deposits to build up in the nozzles. About every five years depending on water quality, you’ll have to replace the internal filter on that nozzle,” he says.
With either type of sprinkler head, there are plenty product options available to split the difference between them. For instance, Moseley uses a lot of matched precipitation nozzles to accommodate a large area with a small nook within a rotor zone.
The biggest challenge in taking advantage of all the bells and whistles can be educating the customer on their benefits, Moseley says.
“The cost difference between them is significant, so it is important to educate the customer on why you are going with triple the amount for one head versus the other,” he says. Contractors should also prioritize creating efficient system designs and getting the proper training to achieve it.