Richmond Nursery, Richmond, Ontario, is an eight-acre site that includes more than 15 gutter-connected greenhouses. Altogether, the site has one full acre under greenhouse glass. At any one time, these greenhouses will contain more than a million plants of up to 1,000 different varieties under cultivation — during the holiday season, the nursery can house up to 14,000 poinsettias alone.

All plants require regular watering, light, and climate control, but the vast diversity under the roof of Richmond Nursery complicates their care and makes reducing costs difficult. Previously, the nursery used timers for controlling lighting, heating, and ventilation. However, these timers had to be constantly adjusted as the hours of daylight changed throughout the year, according to Peter Rofner, general manager of the nursery. Timers set early in the spring could result in lights being on after sunrise. “We sometimes had situations where we were paying for two hours of lighting when it was unnecessary,” Rofner says.

Therefore, the nursery needed to find a better way to control the climate in its site and reduce its substantial electricity and heating use and expenses. Some months, its electrical bill reached approximately $6,000 (CAD), and the natural gas bill totaled $4,000 (CAD) a month for heating. The plant nursery’s owners also wanted to improve control over lighting and increase security.

Natural Automation, Greely, Ontario, surveyed the nursery to assess its needs and met with the nursery’s management group about the type of system they wanted. Louis Levetsovitis, owner and chief installer for Natural Automation, decided a HAI by Leviton environmental control system was the best fit for the nursery’s particular challenges.

For a photo gallery of the nursery’s environmental control system, click here.

Levetsovitis felt the system could take on the challenge of controlling the environment for the nursery, ensuring that the heating, ventilation, lighting, and water usage were correct for the million living plants. He also had to integrate gas-fired CO2 burners, which increase the level of carbon dioxide in the greenhouse air to encourage the plants to grow faster, into the system. The nursery’s four Priva burners provide the needed CO2, and they also produce heat and water vapor needed for plant growth. “They look like jet engines,” says Levetsovitis, explaining that to keep the CO2 level of the burners at legal limits, they are monitored with thermostats and CO2 detectors. “The sensors are important for the system to precisely monitor the CO2 level. If the system detects that the level has exceeded the threshold, then the HAI by Leviton system shuts them down.”

Before the HAI by Leviton system, Rofner had developed a Linux-based software application that displays in a graphic format the temperature inside and outside the greenhouses and the resulting growth rate of the plants at the nursery. Rofner used this graphical representation of the data to assist in managing the nursery’s expenses and wished to continue to use the data from this application, but wanted to port the data over to the new system.

The open architecture of the HAI by Leviton system allowed the continued use of Rofner’s program. Levetsovitis was able to integrate the graphical program into the system so that the growth data could be used in controlling the nursery’s life-sustaining functions. “With other systems, you would have to buy an expensive module to do that,” says Rofner. “Other systems are proprietary. HAI by Leviton gives me enough control so I could do what I need to do.”

The HAI by Leviton system has reduced the electrical and natural gas expenses for the business. The Richmond Nursery’s electrical expense was halved per month to $3,000 (CAD), and the natural gas expense was reduced to $2,500 (CAD) per month. These monthly energy savings equate to yearly savings of $36,000 for electricity and $18,000 for natural gas.

In addition, Rofner receives detailed data on the operation of the nursery. As conditions, seasons, and plant species change, the system will automatically adjust and optimize the nursery’s systems for water, ventilation, heat and CO2. “We’ve made huge strides over what we used to have,” Rofner says. “It’s easier for us to program supplemental lighting, giving us control we didn’t have before. Overall, the installation of the system has worked for us.”