Is 240 CMF exhaust fan too much for a 2x4x6 tent?

Astral22

Well-Known Member
Hi, i'm looking for a very quiet exhaust fan and i found one called Silent Vents TT rated at 240 CFM minimum. Is this too much for a 2x4x6 tent? What CFM would you recommend me?

I'm using a 300w LED: Mars Hydro TSL2000
Carbon filter
Minimal ducting
Normal room temperature

Unfortunately AC Infinity Cloudline is not available in Europe so i have to look for other fans, otherwise i would get that one.
Thanks!
 

coreywebster

Well-Known Member
The TT fans I tried were awful rattling shite.
But post a link to it or tell us the dB rating

Give me a minute and I will post a link to what I use.
Quietest fan on the market .

Are you sure AC infinity are not available?
Last I heard diyleduk were stocking them.

As for cfm for your space, it's down to your ambient air. If your at 22c and want to be running at 24c it takes a lot more airflow than it does if your room is naturally 18c.
It's about the temp difference.
 

coreywebster

Well-Known Member
The above fans do not shift as much air as some but you won't find many fans running 22db .

I used to run the 4" in 2x4ft x 5ft tent. 240w quantum boards.

Also had the 6" which I had split to a 3x3 and 1mx1m tents each with around 320w of good led.

Like I said though, depends on the temp coming in as to how much airflow you need to maintain desired temp.
 

coreywebster

Well-Known Member
They are so quiet you will have to put your head next to it to check it's even on.
Any circulation fans will be much louder.
Yet to find a really quiet circulation fan
 

DCcan

Well-Known Member
If you want quiet, then increase the ducting size to the largest size you can stuff in the tent, cut down on bends, increase the carbon filter size.

Then hook it up to a duct reducer to your existing fan, or get an larger EC motor fan that uses PWM signal to control.
Gets rid of all the air transfer sounds and lets the fan draw as much as needed. Whisper quiet with 8" vs 4" intake and exhaust ducts, oversized filter lasts forever.
 

Eastownclan

Well-Known Member
You can order a fan speed controller from Amazon for $10. If the cfm is too much, you can dial them down to 50% safely.
 

DCcan

Well-Known Member
You can order a fan speed controller from Amazon for $10. If the cfm is too much, you can dial them down to 50% safely.
Those just clip the AC supply voltage and produce a horrible low toned harmonic in your motor that travels thru the house. They reduce the speed and air volume, but increase resonant harmonics and audible noise, cause premature wear on the motor.

If air movement from the ducts is making the noise, then solve that.
If the motor makes the noise, then work on that.
 

Astral22

Well-Known Member
Thank you very much for the replies.

The ambient temperature of air going in is around 20C
Also i will be exhausting in the same room with an AC unit and dehumidifier, occasionally opening the windows and doors of the grow room during winter.

These are the fans i'm interested in, what do you think? They're rated at around 30dB

Unfortunately i can't order AC Infinity from UK either because of Brexit, it's gonna cost me around 35% more (VAT + customs) and i would have to wait for much longer shipping than usual. Also i prefer to order any equipment from EU to avoid customs altogehter.

I've seen these 'boxed' fans before, just wasn't sure about them. I'll check that, the larger filter and fan speed controller as well.

But if i was to buy this Silent Vents TT, do you think it would be ok? 240CFM is the minimum on 2nd speed, maximum is 325CFM
There's also a smaller 4'' fan with less CFM but it's only 15€ cheaper than the 6'' so i'm not sure if it's worth it
What would be minimum CFM required in my situation?
 

end_of_the_tunnel

Well-Known Member
Hi Corey. Good to see you back. Missed all your helpful posts.

I wish I got the fan shown in your link. But have to tell you that particular vendor shop on ebay is run by a bunch of cowboys. I would strongly advise no forum member to buy from them or their other ebay accounts. It is pretty straight forward to click on their negative feedback and see some of the experiences that buyers have had.

Clicking on business details of all the above show they are one and same. AC Importers. Units 19 and 22. Negative feedback for all four is atrocious. You cannot blame the courier for sending different model or mixed up parts. Cowboy operators.
 

coreywebster

Well-Known Member
Hi Corey. Good to see you back. Missed all your helpful posts.

I wish I got the fan shown in your link. But have to tell you that particular vendor shop on ebay is run by a bunch of cowboys. I would strongly advise no forum member to buy from them or their other ebay accounts. It is pretty straight forward to click on their negative feedback and see some of the experiences that buyers have had.

Clicking on business details of all the above show they are one and same. AC Importers. Units 19 and 22. Negative feedback for all four is atrocious. You cannot blame the courier for sending different model or mixed up parts. Cowboy operators.
Nice to be back and to see you too mate.

I've ordered 4 of those fans in various sizes from gardeners Corner and some other stuff without problem.
But I won't argue with negative feedback , I hadn't checked it when I bought the first fan and since it went well I continued to shop.

Point taken though.
 

coreywebster

Well-Known Member
Thank you very much for the replies.

The ambient temperature of air going in is around 20C
Also i will be exhausting in the same room with an AC unit and dehumidifier, occasionally opening the windows and doors of the grow room during winter.

These are the fans i'm interested in, what do you think? They're rated at around 30dB

Unfortunately i can't order AC Infinity from UK either because of Brexit, it's gonna cost me around 35% more (VAT + customs) and i would have to wait for much longer shipping than usual. Also i prefer to order any equipment from EU to avoid customs altogehter.

I've seen these 'boxed' fans before, just wasn't sure about them. I'll check that, the larger filter and fan speed controller as well.

But if i was to buy this Silent Vents TT, do you think it would be ok? 240CFM is the minimum on 2nd speed, maximum is 325CFM
There's also a smaller 4'' fan with less CFM but it's only 15€ cheaper than the 6'' so i'm not sure if it's worth it
What would be minimum CFM required in my situation?
Sorry for not replying earlier, the fan you linked is far from the vents TT fans I bought long ago that I said rattled. So I hope I didn't put you off buying.

Happy growing
 

Astral22

Well-Known Member
Sorry for not replying earlier, the fan you linked is far from the vents TT fans I bought long ago that I said rattled. So I hope I didn't put you off buying.

Happy growing
It's alright, thank you, you've been very helpful anyway :)

I decided not to buy that fan because it's way too expensive at 250€ just for the added mineral wool... And it only has 2 speeds, the lowest speed is still too high and loud. It would require an extra speed controller to lower it down, but i honestly i don't know if it's gonna work properly so i don't think it's worth the hassle..

Instead i will look for Mars Hydro or Spider Farmer new fans, they copied AC Infinity with the temp/humidity control. 6 inch, 350 CFM, 35 dB and it's around 100€

If not for those, then the next choice would be a standard Vents TT 150 with similar specs as the Mars Hydro/Spider Farmer fans, but only a temperature controller, no humidity.

Another question if you don't mind answering, is it ok if i put a carbon filter with a capacity of 350CFM while running the fan at 50-100CFM?
 

jondamon

Well-Known Member
It's alright, thank you, you've been very helpful anyway :)

I decided not to buy that fan because it's way too expensive at 250€ just for the added mineral wool... And it only has 2 speeds, the lowest speed is still too high and loud. It would require an extra speed controller to lower it down, but i honestly i don't know if it's gonna work properly so i don't think it's worth the hassle..

Instead i will look for Mars Hydro or Spider Farmer new fans, they copied AC Infinity with the temp/humidity control. 6 inch, 350 CFM, 35 dB and it's around 100€

If not for those, then the next choice would be a standard Vents TT 150 with similar specs as the Mars Hydro/Spider Farmer fans, but only a temperature controller, no humidity.

Another question if you don't mind answering, is it ok if i put a carbon filter with a capacity of 350CFM while running the fan at 50-100CFM?
Yes that is fine to do.

I use a 450m3/h fan on a speed controller and a 900m3/h filter and it’s only during U.K. summer weather that my fan ever runs at 100%.

Approx 250CFM fan and 500CFM filter
 

Astral22

Well-Known Member
Yes that is fine to do.

I use a 450m3/h fan on a speed controller and a 900m3/h filter and it’s only during U.K. summer weather that my fan ever runs at 100%.

Approx 250CFM fan and 500CFM filter
Thanks for the reply, that's good to hear. So i think i finally settled for my fan and filter.
Now onto the dehumidifier and AC unit next..
 
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