Environmental control system saves nursery more than C$50,000 a year

The Richmond Nursery in Richmond, Ontario, is an eight-acre site that encompasses more than 15 gutter connected greenhouses. Altogether, the site has one full acre under glass. The nursery grows a wide variety of products, from mums and poinsettias to rabbit’s foot ferns and begonias. At any one time the facility will have more than 1,000,000 plants of up to 1,000 different types under cultivation. During the holiday season, the nursery can have 14,000 poinsettias growing in the greenhouses. All of those plants need regular watering, light and climate control. And given the wide variety of plants being grown at the facility, the nursery’s needs were complex – a simple, “one size fits all” care program would not work to reduce costs. For example, the nursery had previously used simple timers for controlling lighting. According to Peter Rofner, general manager of the Richmond Nursery, this solution needed constant adjustment as the hours of daylight changed during the year. If the timers were set early in the spring, the lengthening hours of daylight could lead to situations in which lights were still on even after sunrise. “We sometimes had situations where we were paying for two hours of lighting when it was unnecessary,” Rofner said. With such large-scale, complex operations, the nursery needed a way to better control its site and reduce substantial electricity and heating expenses. The Richmond Nursery was spending approximately $6,000 (Canadian) a month on electrical service and $4,000 (Can.) a month on natural gas heating. The plant nursery’s owners wanted a way to cut these costs and gain better control over the facility’s energy consumption. They also wished to improve control over lighting and increase security. And they wanted to do this with an integrated automation system.

Peter Rofner and the Richmond Nursery turned to Louis Levetsovitis, owner of and chief installer for Natural Automation in Greely, Ontario. Levetsovitis is an Leviton certified installer. Levetsovitis surveyed The Richmond Nursery’s needs and met with and listened to the nursery’s management group about the type of system they wanted. He put together a package of Leviton components to address the nursery’s particular challenges.

Unlike controlling the zones in, for example, a warehouse, system installer Levetsovitis of Natural Automation faced the challenge of controlling the environments for some 1,000,000 living plants. He had to ensure that heating, ventilation, lighting and water usage were correct for many different types of plants. “Specific species of plants get specific amounts of water,” Levetsovitis said. “We went into great detail there.”

Another tricky aspect of the installation was adjusting the watering rate based on the relationship between outside and inside temperature. “When it’s 70° to 80° F outside, it’s 110° F in the greenhouses,” Levetsovitis said. “At that inside temperature, it takes so many more gallons to properly water the plants. For example, at 110° we might need 60 gallons per minute.” And these parameters change with the seasons and the plant species. When it’s cold outside at Christmas time, the nursery raises poinsettias. In the warmth of late spring, a major product is tomato plants. Similar to the watering requirements, ventilation rates and lighting amounts also required fine tuning to season and plant species.

Another interesting wrinkle for Levetsovitis was the need to integrate devices known as CO2 burners. Plant life takes in carbon dioxide and throws off oxygen. The more carbon dioxide in the air, the faster plants will grow and the sooner they can be sold. So the Richmond Nursery uses natural gas fired CO2 burners to increase the level of carbon dioxide in the greenhouse air. The nursery’s four Priva burners provide the greenhouses with more than CO2, they also produce heat and water vapor, two other necessary components for plant growth. “They look like jet engines,” Levetsovitis said. “They are monitored with thermostats and CO2 detectors. We integrated these units into the Leviton system.” One aspect of these CO2 burners that was important to get right was the legal requirements to keep CO2 levels below certain thresholds, for example, below 4,000 parts per million to protect workers at the nursery. “The sensors were important for the system to precisely monitor the CO2 level,” Levetsovitis said. “If the system detects that the level has exceeded the threshold, then the Leviton system shuts down the CO2 units.”

Peter Rofner had previously developed a Linux-based software application for his own use that displays in a graphic format the temperature inside and outside the greenhouses and the resulting growth rate of the plants at the nursery. This graphical representation of the data is a useful tool to assist Rofner in managing the nursery’s expenses. Rofner wished to continue to use the data from this application, but also wanted to port the data over to the new Leviton system. Given the open architecture of HAI systems, Levetsovitis was able to integrate Rofner’s graphical growth tool so that the growth data could be used in controlling the nursery’s systems. “We took data from that graphical software,” Levetsovitis said, “and integrated it into the flow of data in the system. It automatically gets plugged into the larger picture.”

Rofner was pleased with the capability of the Leviton system to integrate the data from his Linux temperature/growth analysis tool. If the nursery had used some other automation system, Rofner would have had to buy a canned piece of software that, in addition to the extra expense, likely wouldn’t have done the job as effectively as the software he had already developed. “With other systems,” Rofner said, “you would have to buy an expensive module to do that.”

The integration of the temperature tool was just one example of how the Leviton system was flexible for the nursery’s needs, one in a variety of ways that Rofner was pleased with the installation of the system for his nursery. “I knew what I wanted and where I wanted it to go, and it went pretty smoothly. Overall, the installation of the system has worked for us.”

Results
The Leviton system has drastically reduced the electrical and natural gas expenses for the business. The Richmond Nursery’s electrical expense was halved from $6,000 Canadian per month to $3,000, and gas expense was reduced from $4,000 to $2,500. These monthly energy savings equate to yearly savings of $36,000 for electricity and $18,000 for natural gas.

In addition to these savings, managing director Rofner also has a complete, integrated system that provides him with detailed data on the operation of his business. And he knows that, with the Leviton automation system now in place, as conditions, seasons, and plant species change, the system will automatically adjust and optimize the nursery’s systems for water, ventilation, heat and CO2.

Louis Levetsovitis was able to accomplish the installation easily and quickly because – unlike other systems that claim full automation but are really only for controlling audio and video in the home – Leviton is a capable commercial grade product. “Leviton is a true automation system,” said Levetsovitis. “Others claim to be commercially capable, but they are essentially AV systems.”

Rofner is pleased with the new Leviton system. “We’ve made huge strides over what we used to have,” Rofner said. “It’s easier for us to program supplemental lighting, giving us control we didn’t have before.” Rofner, who has a system in his home, was familiar with the capabilities of Leviton automation. His home system provided him with ready examples of how Leviton systems can be integrated with a variety of third party gear. He knew that an Leviton system would give him excellent control over his business and would be open to integration with other systems. “That’s why I chose Leviton,” Rofner said. “Other systems are proprietary and closed. Leviton fit the bill so I could have enough control and so I could do what I want to do.”

For more information:
www.leviton.com