Fan Size to Cool 4x4 Tent With A 400w CMH

I am finally moving from the house I was renting as the landlord was only 20 feet from my grow area..Moving to a house out in the country that has a very cool basement. I'm thinking of a 4x4 Secret Jardin tent this time around as my 3x2.5x5 closet just wasn't big enough for me to move around. I know a 400w light is under powering the tent which is ok for me as I may want to run two 400s in the near future. My question to you guys is running a 400cfm fan enough to vent and draw enough air in on it's own? The basement stays relatively the same temp which is around 65 degrees possibly warmer. I was thinking light>filter>fan>exhaust. Or light>fan>filter>exhaust with the latter having the fan outside of the tent decreasing the temps by a few degrees. This fan will be paired up with a Can Fan 66. Any thoughts before I go ahead and start purchasing everything? Super excited to grow in peace...

i would have it set up like >filter>light>fan>exhaust that is how i have mine set up. Check my sig if you wanna see pics

webb107 said:

i would have it set up like >filter>light>fan>exhaust that is how i have mine set up. Check my sig if you wanna see pics

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Ok,, I see what you did. It looks like one 400cfm fan won't be enough. The next size up is just a monster at 720cfm. I was hoping the cool temps in the basement would equate to having to pull less air.

Im not sure about cfm as my fan was measured in m3/h

Find out your cubic feet of the tent. You ideally want to get a fan that can refresh your air between 3 to 5 times per minute. So multiply your cubic feet either by 3 or 5 to get the right CFM.

Assuming you're in a 4x4 with standard 8ft ceilings 112cfm would exchange your air every minute. Whether that would maintain temps (lol no) is another story. 400cfm should do nicely especially considering CMH give off less heat than your standard hps/mh. Also you definitely want filter-light-filter-fan-exhaust. Keeping dust and any other particulate off of your bulbs is absolute priority and should keep your bulbs running for longer and you'll also reduce risk of fire or incidental damage to your bulb.

Don't forget that this shouldn't be the only fan, you should have oscillating fans in your tent for air circulation to prevent infestations and mold, between that exhaust and a circ fan or two with a decent size passive exhaust (assuming 65-70f ambient temps) things should be more than manageable.

i run a 400 cfm fan to cool a 1000 watt light in a 4x4 area......it will be plenty for you. In fact Id get a fan speed controller to turn it down if necessary.

Thanks for the replies,,much appreciated. I think 400cfm will do the job and was thinking of running a Phresh filter primarily because of the light weight opposed to 42 pounds with a Can Filter. Any suggestions on a good filter that's not necessarily a name brand?

I currently use a 350m3/h PRIMA KLIMA filter with an RVK125A1 260m3/h fan and have ZERO smell. i'm based in the UK so unsure if this brand is available to you.



J

look on amazon for carbon filters.....they are cheap....I have two (4" and 6") and both of which work perfectly. Cant beat amazon on prices. although most from amazon have fine carbon dust...If you get one connect your inline fan to it and suck all the dust out first before you run it permanently

lambofgod said:

look on amazon for carbon filters.....they are cheap....I have two (4" and 6") and both of which work perfectly. Cant beat amazon on prices. although most from amazon have fine carbon dust...If you get one connect your inline fan to it and suck all the dust out first before you run it permanently

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Ok..will do, although I don't want to sacrifice scrubbing power for price. Researched fans a bit more and think I will go with a S&P TD 150 even though it is rated at only 298cfm. Read a thread where one of these was able to cool a 4x4 on it's own with plenty of juice to keep it going.