Best fans/inline/carbon filter

What would be your advice for me on sizing air flow (oscillating fans, inline fan and a carbon filter) for a new 39x39x80 tent, under a 315 cmh open hood. I'm looking at running a passive intake (constant negative pressure from the exhaust fan).


I was bouncing back and forth on whether to go for a 4 inch or 6 inch inline fan.

-4 inch
Ac Infinity Cloudline s4/t4

-6 inch
Ac Infinity Cloudline s6/t6
6 inch hyper fan.

And again I was back and forth on getting two 6 inch oscillating fans or a tower fan and figuring out a way to mount it horizontally.

As far as carbon filter sizing and minimum airflow to scrub air I'm kind of lost on the awkward sizing. I'm looking to be pretty stealthy and economical. I'd like a filter that would last at least a few cycles if possible.

I'm throwing the tent in a cinderblock basement room thats roughly 10x5 ft and has direct venting access to outside. My temps range from 40-82° f 45-70% rh all year.

Hoping to order soon and I have started to get buyers anxiety. Any advice would be much much appriciated.

Well the length of duct, bends, any restrictions should be accounted for. Personally I would go 6 inch. That type fan does not cope with static pressure loss well, the trade off for quiet.

As to the carbon filter I have Phat filters that have been going strong for nearly 6 years. Oversize it a little if you can and it will restrict flow less and last longer.

How often is it 82 degrees f in the basement?

Can you source a couple of 6 or 7 inch monkey fans? They are low wattage and oscillate , great for not taking up space.
I used to have a lot of fans for moving air, one was a tower fan mounted horizontal but still takes up some room and one problem with them is if the back of the fan is close to tent wall it seriously impedes the amount of air they blow.

I would suggest laying a sheet of rigid insulation under the tent.

Back to the extraction..
If its not hitting 82f often, like that's worst case once in a while and assuming you went with say 2 monkey fans and your total wattage in there was around 350w then the 6inch would give you maybe 4-5 degrees temp rise on full power.
If your talking 82 degrees all summer down there then you really want to go bigger to keep temp rise to a minimum
But lets say you could cope with a 2 degree temp rise, that pushes your cfm up to 550-600 range.

Really it all comes down to that hottest ambient temp and how often it gets to that range.

Renfro said:

Well the length of duct, bends, any restrictions should be accounted for. Personally I would go 6 inch. That type fan does not cope with static pressure loss well, the trade off for quiet.

Click to expand...

The length of the duct work should be less than 4 ft until it makes it outside with a single s shaped bend. What fan would you suggest I go with instead?

It hits 82 when it is 105 outside without the ac in the basement running. I might hit 83 at the height of the summer max, but I do have central air I can flip on down there to lower it 5-6 degrees comfortably.

I did plan on throwing a 2 inch ridgid foam board down on that section for now.

Most of this is me making room to modify a room for myself and still have meds.

@Renfro any brand/model advice on a 6 inch inline?

Well if you are buying the fan to move air get a centrifugal blower like the vortex ones.

https://hydrobuilder.com/vortex-powerfan-inline-fan.html?opts=eyJhdHRyaWJ1dGU5NDAiOiI2OTY3In0=

That style works awesome, moves a lot of air, handles static pressure losses well and the downside is it's loud.

I have over sized them and run them on a variac to reduce speed making them silent but since they are over sized they still do the job.

So when it comes to an inline fan I consider those to be the best.

@Renfro is that the size you'd recommend I get so I can reduce the noise problem then?

(Eventually this will be a drying tent less sound and power is a great thing)

Well if you wanna do the oversize method I have a 10 incher on my 2x4 tent, I put 2 high CFM kits on the tent. Running the 10 inch vortex at 30 volts off my variac causes the tent to suck in hard but you can't hear the fan. If I crank it up to 50 the tent looks like its gonna implode, haven't had the nuts to crank it lol.

Another reason I like big blowers, they are more versatile. Change things up in the future and you have the fan to handle more. Use a variac for speed control, some speed controllers will make the motor groan because its not a sine wave.

@Renfro I've never wanted to see your house more...

It's fucking insane lol. Come down to Pueblo

Renfro said:

Well if you wanna do the oversize method I have a 10 incher on my 2x4 tent, I put 2 high CFM kits on the tent. Running the 10 inch vortex at 30 volts off my variac causes the tent to suck in hard but you can't hear the fan. If I crank it up to 50 the tent looks like its gonna implode, haven't had the nuts to crank it lol.

Click to expand...

What brand variac did you buy?
10 in fan for a 2x4!! Dam

I just got a cheap chinese variac off amazon. It's such a basic piece of equipment. Just make sure it is rated for the amperage of the fan or more.

This is the one I ordered, 20 amps is overkill but it was just a few bucks more than the smaller one that I was looking at. So I have the flexibility to use it for something bigger in the future if I ever want to.

https://www.amazon.com/gp/product/B07KM13B2K/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

https://www.amazon.com/YaeCCC-Transformer-Variable-Voltage-Regulator/dp/B078Z7GL9H/ref=sr_1_1_sspa?keywords=20+variac&qid=1563421852&s=electronics&sr=1-1-spons&psc=1

Thats a cheap one that would do the job, just get the right wattage

This is a 10 inch vortex with variac on a 2x4 gorilla HD tent with 2 high CFM kits installed lol I run it at about 30 - 40 volts.

I also got a hella deal on that fan, the place had it priced at $117 for a while (less than the 4 incher!). I should have bought them out lol.

I'm still thinking I'll end up going with one of the ec fans. Mostly because of sound and as well as going up sizes in the carbon filter/buying a variac and those costs going up. Not to mention building a bracket system to hang the thing. Unless you just don't think it would work for me.

But I am considering getting a couple of larger centrifugal one for my permanent room down the road now.

Renfro said:

Well if you are buying the fan to move air get a centrifugal blower like the vortex ones.

https://hydrobuilder.com/vortex-powerfan-inline-fan.html?opts=eyJhdHRyaWJ1dGU5NDAiOiI2OTY3In0=

That style works awesome, moves a lot of air, handles static pressure losses well and the downside is it's loud.

I have over sized them and run them on a variac to reduce speed making them silent but since they are over sized they still do the job.

So when it comes to an inline fan I consider those to be the best.

Click to expand...

Ya my favorite fan so far. I bought mine from Hydrobuilder when they were all on sale a few months ago. I got my 6" for $112, and wish I would have bought more. It was a great deal.