401 to 600 CFM

Inline fans rated between 401 and 600 CFM. This range covers most 6-inch duct runs and rooms of roughly 400 to 600 cubic feet exchanging their full volume about once a minute.

Size the fan to the room, not to the light. Start by dividing the room's volume in cubic feet by the number of minutes you want a full air exchange to take, then add 20 to 40 percent back for the carbon filter, the length of the duct run and every elbow in it. LED fixtures put less sensible heat into a room than the HID lamps this guidance was originally written around, so an LED room of a given size usually lands at the lower end of the range. Our guide on how to find the right CFM fan walks through the calculation.