One of the biggest trends among high tunnel growers is a push towards automation. Both natural and mechanical greenhouse ventilation equipment can be automated with an environmental control system. Automating your ventilation is one of the best upgrades that you can make for your high tunnel, with a clear return on investment.
To understand the benefits of automation, let’s look at one of the most common high tunnel cooling methods: roll-up sides.
Automating Roll-Up Sides
On an average day, the temperature inside a high tunnel will follow the same curve as the outside temperature – it will rise with the sun, peak around midday, and then drop as the sun sets in the evening.
Most growers without automation will fully roll up their sides at some point in the early morning and fully close them in the evening. In the summer when outdoor temperatures are highest, the high tunnel will reach ideal growth zone temperatures for a few hours in the late morning and in the early afternoon.
If you open your roll-up sides even one hour too early, you risk creating a sharp drop in temperature inside the greenhouse. It will then take more time for the high tunnel to heat to the optimal growth zone. Open too late and you risk overheating the greenhouse and stressing your plants. It can then be difficult to bring the greenhouse temperature back down as outside temperatures continue to rise. As one of our growers recently shared, “It’s a lot harder to cool a greenhouse in the summer than it is to heat it in the winter.”
Automating your roll-up sides takes the guesswork out of the equation. An environmental control system constantly monitors and adjusts ventilation based on temperature readings. Rather than keeping sides fully open or fully closed at all time, a mechanized system can also roll up sides in incremental amounts – say, six inches at a time. This can keep your plants in the ideal growth zone for the maximum time possible.
Benefits of Automation
A 2024 field study by Dr. Vern Grubinger with The University of Vermont Extension looked at 41 farms that were growing tomatoes in high tunnels. It compared the top ten highest yielding tunnels with all others, which showed a 94% difference in total tomato yield per square foot.
One of the starkest differences between the top-yielding tomato growers and all others was the use of automated side ventilation. Seventy percent of the top-yielding tunnels used automated side ventilation, compared with just 10% of all others. The average output from the top-yielding tunnels was 3.5 pounds of tomatoes per square foot, versus 1.8 pounds from the rest of the farms.
Automating Fans, Shutters and More
If you have other cooling equipment in your high tunnel, such as a ridge vent, gable shutters and HAF fans, these systems can also be automated to optimize growing conditions. A controller like the Bartlett ClimateBoss allows for programmable temperature settings in different stages. Each piece of equipment can be controlled based on a set time or temperature, optimizing growing conditions throughout the day.
ROI of Greenhouse Automation
Automating your greenhouse cooling can quickly pay off by reducing energy use and labor demands. It can also create better growing conditions for your plants, maximizing crop quality, uniformity, yield, and ultimately – profits. With a one-time investment, ROI can be felt as quickly as one growing season.
There may also be funding available to support high tunnel automation. The NRCS Environmental Quality Incentives Program, or EQIP, includes funding for the On-Farm Energy Initiative. Through this program, financial assistance is available to farmers for energy efficiency upgrades, such as ventilation and fans and other greenhouse improvements. Learn more on the NRCS website or on Rimol’s NRCS Resource Center.
Discuss Your Automation Strategy with an Expert
Rimol’s team of regional sales representatives are available to discuss making automation upgrades to your high tunnel. We can work with you to design an automation strategy that works with your equipment and crop needs. Reach out to us today for a consultation!