This article originally appeared in the April 2018 print issue of Cannabis Business Times. To subscribe, click here.
For your greenhouse facility to operate at its best, you must properly plan in advance to ensure that the structure and its components are well-maintained and functioning properly.
Part I of this special series explored the importance of climate-control upkeep, monitoring methods, care for piping and valves, and more. Here, you’ll find tips for ensuring adequate airflow, facility cleanliness, evaluating fixtures and shade curtains, as well as a special “lightning-round” of miscellaneous tips for additional efficiencies.
Managing Airflow
1. Air circulation in a greenhouse—a separate concept from ventilation—is best achieved with horizontal air flow (HAF) fans designed for this purpose. Avoid using standard box fans. HAF fans need to be sized correctly for the cubic feet of the air mass and installed in sufficient numbers to make a circular current in your greenhouse. Air has weight, so momentum will carry it with little energy input from the fans once it flows in this pattern.
The total fan capacity in cubic feet per minute for this circulation pattern should equal one-fourth of the greenhouse volume, according to the text “Greenhouse Engineering,” a Cooperative Extension publication by Robert A. Aldrich and John W. Bartok, Jr. Ideally, these fans should be integrated into your control system so that they shut off when the ventilation fans are cooling the room. Otherwise, they will create turbulence that will disrupt the parallel flow across the greenhouse, reducing the cooling efficiency.
2. Circulation air velocity should be a minimum of 50 feet per minute (fpm). At the very least, you should see some flutter in your leaves at their maximum height and density.
To read the full article in the April 2018 print issue of Cannabis Business Times, click here.
Top Image: © Georgia K | Adobe Stock
