1st timer grow tent setup questions

[Tonloc36]

Preparing for my 1st grow and I've researched for about a month now. So far I have a 2.6'x2.6'x7' tent and am waiting for 2 300watt old style mars hydro led lights to be delivered (not even sure if this is too much or not enough light). The tent is in my basement where the temp is about 60-65 degrees f. What size/type/ccm exhaust fan/filter would I need for odor control? Something with a speed controller? Starting out with northern lights auto in soil (maybe 3 or 4 in this space?).
Thanks.

 

[Papageno]

As far as size of filter you the easiest answer is to go to the Phresh filter web site and use their calculator. The math is fairly straight forward but the Phresh site has a real nice calculator so you don't have to think.

More important is the fan size and controller. Fans are loud. If you buy a larger fan and run it on a speed controller at half speed it wont be loud anymore. I have a much larger tent and according to the calculations I need 200CFM to contain the smell. So I have a 400 CFM fan (6 inch hydro farm $80) on a 400 CFM filter (6x16 Phresh for $129) on a speed controller running a bit over 200 CFM. This also helps the fan have a much longer life. Running fans at full speed full power is not bad but will for sure wear them out faster.

I am only 4 weeks into bloom on this setup and so far so good but I wont know for sure for a few weeks.

So you could go smaller but it doesn't get much smaller then that setup. ALSO if you overbuild a bit like I did AND you have made sure to seal everything correctly then if you do start to smell something you can just turn up the fan a bit and it should all be fine. But if you build a room that needs 200 CFM and you put 200CFM fan and filter in it you are just asking for your neighbors to smell it some day.

Also when running a slightly overbuilt system on a speed controller you will have a little better control of your temps.

 

[Tonloc36]

Ok the phresh says I should use a 166cfm filter but to use the next size up which is a 4" 200cfm. Would a190cfm 4" fan be ok? According to my calculations, running it at 50% would clear the room approximately every 30 seconds. My thinking says id have to run the fan at most 25%. I've read that running a fan at less than 50% could cause a hum. Is this true? I don't want to suck my plants up through the filter either. Just hate to make a $250 mistake with my setup.
Thanks

 

[Papageno]

There are many kinds of fans and some suck worse than other (HAHAHAHAHA)

A hum can happen for a few reasons. Cheap fans can be out of balance and that is the worst problem. If you have a good speed controller it should not hum. There are many things you can do to quiet the noise so look that up on youtube.

So 200 cfm is not much more than 166. In fact that is close enough to being the same and not really over built at all. If you need 166 and have a 200 CFM filter I would run it at 200 CFM. Now maybe you use a 400 CFM fan at 50%. But that can lead to problems as well. You can burn out your fan if you overload it. Think about this. You have a 600CFM fan on a 100CFM filter that is full and blocked up...you could be killing that fan fast.

I would stick to the fan being the same or smaller then the filter needs to keep the fan happy and make sure the fan can clear out the room well at a speed less than full speed.

If you need 166 CFM...you want a 300-400CFM fan running at half speed on a 200CFM or larger filter. But just remember that the 200CFM fan can choke a 300 or 400 CFM fan.

That is why I choose a 400 on a 400 for a situation that called for I think 250 or something like that.