Do I Need Circulation Fans?
Yes, you definitely need circulation fans in most greenhouses, especially those with heating, automated ventilation, and/or light deprivation! In addition to cooling and exhaust fans, your plants will benefit greatly from circulating air. Circulation fans, also known as horizontal airflow fans (HAF), provide continuous air movement which helps maintain uniform temperatures, humidity, CO2, and increases the structural integrity of the plants much like the wind strengthens plants in nature.
Circulation Fan Benefits
- More efficient heating and cooling
- More even temperatures, humidity, and CO2
- Reduces conditions that encourage pests and pathogens
- Helps plants be more productive
- Reduces environmental stress for plants
On a plant level, optimum air circulation increases transpiration (the process of the leaf absorbing and expelling moisture). Too much airflow can result in “windburn” aka “clawed leaves.” However, circulatory airflow is especially important in light deprivation greenhouses. It can also be beneficial in greenhouse heating to mix air and maintain a uniform temperature throughout the greenhouse.
Types of Circulation Fans
- Stationary mounted circulatory fan
- Mounted or standing oscillating circulatory fan
- Laminar flow fan
Automated Ventilation Packages
Hortitech Direct offers several options for buying circulation fans. The Green Breeze HAF (pictured above, stationary mounted circulatory fan) is a top seller. Wondering how many and what size fan you need for your greenhouse? That is largely based on the size and shape of your greenhouse, but for our greenhouse kits, here are the automated ventilation configurations that we recommend. We also recommend connecting these ventilation components to the VC115 Single Stage Thermostat by J&D Manufacturing. You can also check out our greenhouse kits with automated ventilation in our store!
- 20'x20' Greenhouse: 2x 12" Green Breeze HAF Fans, 2x 30" Power Intake Shutters, 2x 24" ES Shutter Fans
- 20'x48' Greenhouse: 4x 12" Green Breeze HAF Fans, 2x 36" Power Intake Shutters, 2x 24" ES Shutter Fans
- 20'x96' Greenhouse: 6x 12" Green Breeze HAF Fans, 2x 48" Power Intake Shutters, 2x 36" Wall Master Exhaust Fans
- 30'x48' Greenhouse: 2x 20" Green Breeze HAF Fans, 2x 48" Power Intake Shutters, 2x 36" Wall Master Exhaust Fans
- 30'x80' Greenhouse: 4x 20" Green Breeze HAF Fans, 2x 48" Power Intake Shutters, 2x 36" Wall Master Exhaust Fans
- 30'x96' Greenhouse: 4x 20" Green Breeze HAF Fans, 2x 48" Power Intake Shutters, 2x 36" Wall Master Exhaust Fans