Airflow is a vital part of the growing process, especially indoors where natural environments must be replicated. Within a grow tent, there are three different types of air pressure you can apply: positive pressure, neutral pressure, and negative pressure. This article will focus on negative air pressure, which exhausts more air than it takes in.
Creating Negative Pressure
Turn on your inline duct fan to begin the air exhaustion and raise the fan speed until you achieve your required CFM. In a grow tent setting, its concaved walls should tell you there is adequate negative pressure inside. You can also tell by placing your hand in front and an intake opening and feeling air rushing in.
If your grow build includes an active intake system like a booster duct fan, simply make sure its force is lesser than that of your inline duct fan. Your active exhaust fan should always be more powerful than your intake fan.
Keep in mind leaving your fan on at high speeds for an extended period will put an unnecessary burden on its motor.
The Benefits of Negative Pressure
When growing indoors, your primary goal is to recreate the benefits of the outdoors, which includes ample sunlight and fresh air. The latter can be introduced with or without an intake fan, as the exhaust fan often pulls double duty.
This effect is most beneficial to your plant growth because it makes climate control easier, only requiring small adjustments of your exhaust fan. It allows for a stable environment while avoiding any risk of mold or mildew forming on your plants. It also has the added benefit of managing pungent smells. If left unchecked, odors can get stronger as it concentrates inside your grow tent, and eventually seep out as it seeks an outlet.
While there are reasons to use positive pressure or equalized pressure in your grow tent, negative pressure is a surefire way to create the ideal and most stable environment for your plants to thrive. It’s a simple step for growers to take and can always be adjusted as needed.