Hey all,
I have my 2x4x6 and have a Phresh Carbon filter coming. Im hoping for some opinions please! - Best bang for buck 4” inline fan?? Im looking for the best low noise/power draw fan up to 200 CFM. With this size tent should i pass on the centrifugal type? I dont intend on using much ducting. All help is much appreciated!! 
I like the AC Infinity fans, Cloudline S4 or T4 for added temp/humidity controls.
Welcome ! good choice on the carbon filter you will be happy with their product.
Which phresh filter did you order and do you know cfm rating and static load of it? I have 4 in ac infinity fan, it doesn’t do great with filter attached. O would probably go with 6" model like the s6 and 6x18 filter from phresh or larger. Slightly overkill for your space, but will work like a charm.
I ran a 4" AC Infinity in a 2x4 and it didn’t get the job done. Wouldn’t pull a negative pressure on my tent either. I’d go up a size, as AC Infinity products are very good. Unlikely another brand (that I know of) that will perform any better.
I ordered the 4” Phresh filter rated at 200 CFM. From all the info i could find it seemed the 4” would be sufficient for a 2x4x6. I was worried any bigger would suck in the tent too much.
All AC infinity fans have speed control.
My lighting is the QBL 2 as recommended on here 
. I snagged the last one! 
. I understand this light is quite good and doesnt put out too much heat…
You and your plants will love it.
Im excited in any regards. Just received my tent which was advertised as 1680D Oxford material… i open the box and the instructions say its 600D 
. So that has to be returned also! Thanks for the help all
Im not sure on the static load. I have actually never heard of “static load” in my research haha
I have the ac infinity and agree with others. It wasn’t enough for even a 2x2 with no filter attached. So I moved that to use as my intake fan and have a growneer 4” fan that is at least double the power of the ac infinity (even though they’re rated close to the same CFM). The con is it is almost double the decibel level as the ac infinity. Pro is it moves more air and is half the price. Both fans have adjustable fan speed.
This is the same fan as the growneer just rebranded.
https://www.amazon.com/gp/aw/d/B01CTM0H6I/ref=sspa_mw_detail_1?ie=UTF8&psc=1
I have that vivosun fan and it is really loud. Just displaced with the ac infinity “8” inch the ac infinity sucks the tent at half the speed and half the noise.
Go with the ac infinity 6 inch fan. The thing works great. No problems here. Have them in a 4x4 and 5x5 negative pressure all day. I also use a 6 inch intake for the 4x4 and 8inch for the intake on the 5x5. My plants love the fresh air.
Cheers! Looking like most people leaning towards the 6” for a 2x4x6 tent. Excuse my ignorance but i was assuming the intake flaps at the bottom of the tent coupled with an inline exhaust would be sufficient for air movement. Should i be sorting out an intake fan also then?
I have an AC Infinity pushing air into my tent, but leaving a port or 2 open near the bottom should be fine. It’s just an option.
I had to run an intake because the room is sealed but the vents at the bottom of a tent are sufficient. You’ll just want to make sure to add some light traps so you’re not getting light leaks during lights off
I have 4 for these fans and they have been running forever. One is starting to rattle thought. When I buy more I will likely go with the AC Infinity Cloudline models.
https://www.amazon.com/dp/B074XBXFPD/?coliid=I33CUJ5EGH80E4&colid=2F3LA2A7TET0W&psc=0&ref_=lv_ov_lig_dp_it
I’m told by a few folks here that the bearings are better and last longer.
They’re saying once you put a carbon filter on it, the 4" fans just don’t cut it, don’t know, never put a carbon filter on a 4" fan, I use 6" fans for 3x3 tents.
Not surprised. Most of the filter manufacturer won’t give it to you, but should be available for phresh filters. The actual amount provided by filter isn’t super critical, because type and length of duct along with amount of bends in duct will all increase the static load on your fan. Small mixed flow fan won’t deal with large static load well. Just means if you wanted that style of fan, you should go a little bigger. A 4 inch centrifugal fan would do fine for most, and they’re cheaper. They’re just loud, not as efficient, and have poor speed control in comparison.