Xtra Fan-Speed, what is it and why is it important?
A well set up ventilation system will keep your room in a state of negative pressure. Simply put, this is when a vacuum is created by more air being drawn out of the room than is coming in. A sign that your room is under negative pressure is if the room walls (in case of a grow tent) are seen to suck in slightly, or an outward opening door (in case of grow room) pulls itself to a close when left slightly ajar. In contrast, positive pressure would see the walls of a grow tent blowing out, or door to room blowing open.
Maintaining negative pressure is an important part of grow room management because it lays down the optimal conditions for healthy growth and prevents odours escaping.
As air flows quickly through the room from the intake toward the outtake fan, it draws a consistent supply of fresh air and co2 through the plant canopy, and takes with it, excess humidity caused by transpiration, stale air, moulds and other airborne contaminants, as well as the smells associated with indoor growing, and exists them efficiently through the ventilation system, which is often filtered.
A room under equal or positive pressure will lack this efficient directional airflow, which will lead to poor and uneven growth, an increased risk of disease, as well as smells escaping through the cracks, gaps and zips of your grow room.
Maintaining negative pressure is easy when you’ve selected the correct size fans and you use a fan controller with Optimized-Flow™, in fact it will happen naturally. But, if your fans are too close in volume through incorrect fan pairing or duct inefficient, fine adjustments can be made to correct pressure problems using any controller that carries our Vacuum-Control™ feature.