I haven’t grown in about 15 years and I am planning to start anew. My plan is to have a grow closet approximately 3x5x8 in my basement. I will also have a 3x5x8 non-grow closet compartment for things like the reservoir, ballast and supplies. The basement is about 60-65 degrees F throughout the year and I plan to have a 400W HPS for a light and use a carbon filter for odor control. I currently have a 300 CFM inline fan. I would like to be as stealth as possible
My question is, should I run my fan at full speed and what size passive intake should I use? Also, what about a passive outtake? I would like to place the carbon filter in the non-grow closet to keep in hidden from view. Should that closet’s outtake vent be the same size as the intake?
Nice! But being that I will be in a closet and the positioning of it, I will have to create vents on the front wall. Both the intake and the outtake. That’s why I want to know what size I should make them to handle the airflow.
1:1 will work fine, but I would allow the intake hole to be a little larger for a host of reasons. Temps & less strain on motor being the two that come to mind.
When you say 1:1 you mean the same area the fan opening is? So in my case with a 6" diameter fan I could use a 6" diameter intake and outtake vent and be okay (realizing larger is better)?
This fan empties my 8’ x 8’ x 8’ green house in 6 minutes. It reduces from 6" down to a 4" vent pipe and there is passive intake. Works fine until the intense summer heat, then nothing lives for long in a green house.
Then mine should be good to go. My basement never gets above 65 degrees F in the summer. That’s not counting the light, but I don’t see that adding that much.
When I ventilated my closet I used 2x the size for passive intake - if the fan is sucking air out through a 6" vent you need at least two 6" vents for passive intake.
But you might want to slow it down to get the temps up in there, hopefully low 70’s or higher with the light on - are you using a heater or just the lamp?
My intention is just the light. I am looking for quality, not quantity. In fact, I am looking to keep yields down (and consequently plant size). So I am not at all looking for ideal solutions. Just workable ones.
In a 5 x 3 space you will only have just over 26 watts per sq foot from 400w. You need closer to 40 watts per sq foot for good yields. I’d run a 600w lamp in there and if heat is an issue an air cooled reflector hood could be the solution. A
The formula I used was square footage of room times 3. So LxWx3 to get my total cfm I wanted to move. By muiltplying by 3 it will change your total air every three minutes. Agree intake air vent should be same size or bigger than exhaust. Also if you go larger than required it gives you better flexibility to adjust your air flow. Also by going larger than required you can idle back your fans so not so noisy. Yes your temp well lights on should be up in mid 70f and lights off I try keep my temp around 10 less than my lights on temp.
While the closet will be 3x5, I won’t be filling it up. I am probably going to just grow 1 small plant at a time. 3-4 ounces will last me about a year so I can easily outgrow my needs.
