# Do those little 6" duct fans work well?



## Hackerman (Apr 26, 2014)

I bought a Hydrofarm Active Air and it is way overkill for my 3 x 5 tent. I have it set real slow, otherwise it would suck the tent inside out. LOL I may use it in my other room.

One of those little 6" inline duct fans would fit perfectly if it would move enough air. Anyone have any experience with these? I have an older one and it is very loud. At least the Active Air fan is whisper quiet.

Anyone? Thanks


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## sawhse (Apr 26, 2014)

I have one but it wasn't enough to keep things cool. I even tried it with my t5's but it just wasn't enough. Course I had to run it through my carbon filter because it gets pretty stinky depending on the strain. So now I use a 4 inch inline for veg and a 6 inch fan for bud.


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## The Hemp Goddess (Apr 27, 2014)

If you are talking about duct booster fans, no.  Duct booster fans are meant to assist larger fans on long ducting runs.  They are not meant to be stand alone fans.  You cannot use them with a filter--they simply are not meant for that and are not strong enough.


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## lyfespan (Apr 27, 2014)

Hackerman said:


> I bought a Hydrofarm Active Air and it is way overkill for my 3 x 5 tent. I have it set real slow, otherwise it would suck the tent inside out. LOL I may use it in my other room.
> 
> One of those little 6" inline duct fans would fit perfectly if it would move enough air. Anyone have any experience with these? I have an older one and it is very loud. At least the Active Air fan is whisper quiet.
> 
> Anyone? Thanks



I use the homedepot site to see what the sones level is for fans as well as all other specs

http://t.homedepot.com/s/inline duct fans


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## lyfespan (Apr 27, 2014)

The Hemp Goddess said:


> If you are talking about duct booster fans, no.  Duct booster fans are meant to assist larger fans on long ducting runs.  They are not meant to be stand alone fans.  You cannot use them with a filter--they simply are not meant for that and are not strong enough.



I'm going to have to disagree here, you can use any fan you like as long as the cfms are appropriate for the cubic footage, length of the run, and other static equipment.

You can use a 400 cfm duct booster inline fan, with a filter on short runs. You just need to do the proper calculations to figure out what setup will work.


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## Dman1234 (Apr 27, 2014)

the fan is likely less than 100 cfm and is useless, adding a filter to it and you need 400 cfm minimum imo.


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## Hackerman (Apr 27, 2014)

I don't have a filter attached. It's just my veg tent. It's only 3x5x7 so that's 105 CF and the fan is rated at 188CFM. That sounds more than adequate. No?

Although, I'm sure I won't be running it at top speed unless it's super super quiet (which I don't expect). Even turned at half speed it's clearing the tent every minute or so.


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## MJ20 (Apr 27, 2014)

As sawhse said..try a 4"..i used a 6" to cool a 400W HPS and worked fine.This was not in a tent however.You might want to think of reinforceing your tent with wood steaks or something that you can use as a frame for the tent to be tied to on the inside so the same problem won't happen again.

But don't waste your time with those ductfans...not enough flow for HID.LED/Fluro YES...HID NO


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## Hackerman (Apr 27, 2014)

Well, we're going to find out. LOL I ordered the fan and I'll try it out. It should be a good test because this tent is using an air cooled hood so the fan will have to pull the air through the hood and then a 6" duct a few feet long and then out the tent. That's a pretty good task for a duct fan.

I have temp and humidity monitors in the tent so I'll have to go by those measurements. As long as it keeps the temp and humidity right, I would probably say that it's doing it's job.


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## Hushpuppy (Apr 28, 2014)

I hate that you ordered those duct boosters my friend. They are worse than useless. I had 4 off them that I used in my 2(3'x4'x4') veg cabinets (2 in each one), and they still didn't move enough air to keep the spaces cool enough. I ended up having to keep them open and place a large ffan outside blowing in until I could afford another centrifugal fan. You will find out. The problem with them is that they are nothing more than space ffans with metal around them. They aren't enclosed in a way that they produce vacuum when running. They push air rather than pulling it because off their inability to create vacuum. Centrifugal fans are enclosed so that the air can't escape around the blades to equalize pressure on both sides. This causes them to work like turbine engines which suck air in and compress it, but the centrifugals don't compress the air as they only have one impellor to create vaccum on one side and pressure on the other side. I would get a small 4" centrifugal for the veg space as you won't be pulling as much, and don't need a filter. This is just my 2cents though.


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## MJ20 (Apr 28, 2014)

^High science there man..i learnt something lol


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## The Hemp Goddess (Apr 29, 2014)

You can put a speed controller on your 6" fan and crank it down to whatever you need.  I am really bummed that you bought the duct fan, too.  They really are pieces of s h i t (if you are a plumber, this is not a swear word).

And JFYI, I use a 6" fan in a space that is 6.5 x 3, so just a foot and a half longer and it is not overkill by any means.  If the walls of your tent suck in too much, kick the speed of the centrifuge fan down and/or create more intakes.  I don't think there is a way in the world that that fan will cool a HID.  I like to exchange my air about 3-4 times a minute.


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## Hackerman (Apr 29, 2014)

How would I really know if it's working properly or not? Is there a way to measure air exchange? I can go by temp and humidity changes but other than that I'm not sure how to tell if there's enough air exchange or not.

And, the only reason I bought this instead of the larger fans was because of size and weight. This fan seems like it's fits perfectly with a tent setup.


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## The Hemp Goddess (Apr 29, 2014)

Yeah, it does seem like it, but it really isn't.  I have a 32 x 32 tent that an inline fan would not keep cool...and that was running 2 150W in cool tubes.


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## nouvellechef (Apr 29, 2014)

Sometimes its hard to hear what won't save you money. They speak the truth man. If you want to grow the best dank possible. Gotta start out right.


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## Hackerman (Apr 29, 2014)

It's not a matter of money. I have a 600CFM Active Air sitting on the shelf I could use.  I just preferred the smaller, lighter fan (if it will do the job). 

Plus.... you never know unless you do it yourself. I'm one of those kind. LOL

However, this will be a tough test to run. If the temp and humidity stay stable that's one indication. However, if the plants suffer from lack of air exchange, we really can't prove that unless we are doing a side by side experiment.

It should be here any day. I'll install it and see if it keeps the temp and humidity stable. If it can't do that, it's an automatic fail and the other tests won't be necessary.


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## Hushpuppy (Apr 30, 2014)

Yeah with the lites in the space being on continuously, you will have heat and humidity build up. If the duct ffans work to remove the heat and humidity then the plants are getting enough air. The best way to test it is to turn on lights and close up space for 1-2hrs and monitor temp/rh, then when temp reaches upper 80s in space, turn on fan and give it an hour to see if they come down at all. Just make sure your lower vents are open :doh: to allow fresh air in.


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## The Hemp Goddess (Apr 30, 2014)

Hackerman said:


> It's not a matter of money. I have a 600CFM Active Air sitting on the shelf I could use. I just preferred the smaller, lighter fan (if it will do the job).
> 
> Plus.... you never know unless you do it yourself. I'm one of those kind. LOL
> 
> ...


 
 Actually you can know even if you do not do it yourself--we all take the word of people who are better informed than us all our lives.  As my boss used to say, "There is no reason to reinvent the wheel".  

 I understand trying new things--I also like to try different things.  I started growing hydro years ago before many were doing it.  I went from MH to T5 before others I know, I experimented with organic hydro, etc, etc.  However when a bunch of people with decades of experience tell me something will not work, I pay attention.  Keep in mind that we all have your best interests at heart--all we really care about is helping you to grow the best bud that you can.


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## Hackerman (Apr 30, 2014)

You're such a sweetheart. 

Buuuuuuuuuuuuuuuuuuuut, LMAO 

I have spent my live doing the things that the elders said couldn't be done. It's just the kind of person I am. LOL It has provided a very successful and rewarding life for me. Every day and every event is a new challenge because I do it differently every time. Like I said, I'm just messed up mentally so it's how I am. LOL

Just because we used to make butter in a churn, doesn't mean a blender won't work better. The world moves and the universe revolves around change. I love change.

I could never abandon this experiment now. LOL I have to prove the elders (or myself) wrong. I can't wait for this fan to get here,now. LOL

Just to sugar coat it a little, I will put a speed controller on it and run it at less than full speed. I like QUIET and I am thinking it will be too loud at full speed anyway. 

On a side note: I am really having fun here. You people are really nice and very well informed. I used to love growing pot. It was my favorite hobby. I cross bred and even tried the grafting to hops experiment. LOL What a flop. LOL About 10 years ago, it all changed and the hobby died. It was just a source of pot for the last 10 years or so. This forum and you nice people have really re-kindled the hobby for me. And, I think you for that. I'm pretty harsh and I mostly walk against the flow so I hope I don't rub too many people the wrong way. If I do, feel free to let me know. After 60 years of being like this, I'm used to people being honest (and somewhat harsh) to me. LOL Thanks again


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