Speed controller question

So I'm starting a small grow, 2.5 X 2 X 6. Using 400w MH/HPS and a 6" fan rated at 435 CFM. I know that I should get a carbon filter higher than the rating of the fan, but would 475 CFM on the filter be enough if I have a speed controller hooked up to the fan? I'm assuming it wont usually run at 435 CFM since it's only a 400w bulb. Thoughts anyone? Should I go for a higher rating on the carbon filter?

Yup, You're fine with the speed controller; it's good to have a fan working on half speed or even less, its always a quieter option (than a smaller fan working full speed).

I agree completely.

475 for the filter is plenty.

You just need to make sure that the CFM of the filter is higher than that of the fan.

Job done.


I use a 400w setup with a 250CFM fan and a 600CFM filter. Lol.

My room though is 3.2x7x8ft.

But my 250CFM fan cools and exchanges the air plenty. I too use a speed controller.


Why the 600cfm filter you ask?

Longevity. Its currently 18months old and not a thing gets past it!!




J

So i take it its a temp reading fan speed controller i have a fuzzy logics night and day variable fan speed controller using a 440 CFM Ecoplus supreme fan with a 6" x 16" 400 CFM carbon filter works great running it in a small closet with a 1000 watt lamp. I keep the day temp at 75 so the fan kicks on more than yours might but long story short yes that will work my fan does not run much during the dark period and i don't smell a thing until i open the room. All stank eliminated and my filter CFM is lower than my fan.