# Using a variable speed controller for your inline fans



## Hackerman

Anyone doing this? I use variable speed controller with my Hydrofarm Active Air ACDF6 Centrifugal fan (my exhaust fan).

I tried to use this same speed controller with my Hydrofarm ACFB66" booster fan (my intake fan) and it wouldn't work properly. I did a little reading (still doing) and it seems there are 2 different types of motors in these 2 fans and they require different types of speed controllers.

While I was reading, I saw a sticky here that said you can't use ANY speed controller with a single speed fan. I don't know how old that sticky is or if it's accurate but it got me thinking if I am OK with the speed controller on these fans. ( http://www.marijuanapassion.com/forum/showthread.php?t=1965 )

Anyone using speed controllers on their fans?


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## TrollMaster5000

no they really dont work with the brushless non capacitor motors ( the small booster fans ) multi speed fans are of this type actually have more then one set of windings on the motor one winding is longer then the other creating a set amount of magnetic force when turned on  one of the settings
and also even though they are sold to be used with the larger extraction fans 
and alot of people use them 
a capacitor start motor runs on a rolling wave length of current 
and that rheostat fan controller puts out a square wavelength that is why you often hear that growl when you turn it down 
the only true way to turn down that capacitor start fan properly and using the proper wavelength shape is with a variac style controller or a actual step down transformer


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## sawhse

Yep I use them on both of my fans. My 4 and 6 inch fans. One is called a speedster  and the other is a Growbright. Both work great. My can max 6 has high and low switch and I just set it on high and use controller.


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## Hackerman

TrollMaster5000 said:


> no they really dont work with the brushless non capacitor motors ( the small booster fans ) multi speed fans are of this type actually have more then one set of windings on the motor one winding is longer then the other creating a set amount of magnetic force when turned on  one of the settings
> and also even though they are sold to be used with the larger extraction fans
> and alot of people use them
> a capacitor start motor runs on a rolling wave length of current
> and that rheostat fan controller puts out a square wavelength that is why you often hear that growl when you turn it down
> the only true way to turn down that capacitor start fan properly and using the proper wavelength shape is with a variac style controller or a actual step down transformer



Are the inline fans that we all use like the Hydrofarm Active Air ACDF6 Centrifugal fan (my exhaust fan) the multispeed type? Or, should we not be using these speed controls with them?


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## Hackerman

sawhse said:


> Yep I use them on both of my fans. My 4 and 6 inch fans. One is called a speedster  and the other is a Growbright. Both work great. My can max 6 has high and low switch and I just set it on high and use controller.



This was another thing I ran in to. I bought the same Can fan and took it back because I was hesitant about using a multi-speed control in addition to a 3 speed switch.


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## sawhse

Yep felt the same way the manual said you can't use another type of controller wasn't sure what it was. So I goggled the other type and it was okay to use speed controller on that model


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## Kraven

TrollMaster5000 said:


> no they really dont work with the brushless non capacitor motors ( the small booster fans ) multi speed fans are of this type actually have more then one set of windings on the motor one winding is longer then the other creating a set amount of magnetic force when turned on  one of the settings
> and also even though they are sold to be used with the larger extraction fans
> and alot of people use them
> a capacitor start motor runs on a rolling wave length of current
> and that rheostat fan controller puts out a square wavelength that is why you often hear that growl when you turn it down
> the only true way to turn down that capacitor start fan properly and using the proper wavelength shape is with a variac style controller or a actual step down transformer





Exactly what he just said...good post!!


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## TrollMaster5000

Hackerman said:


> Are the inline fans that we all use like the Hydrofarm Active Air ACDF6 Centrifugal fan (my exhaust fan) the multispeed type? Or, should we not be using these speed controls with them?



thats a capacitor start fan so you would need a variac controller in the proper amperage for your fan which is actually a step down transformer and not a rheostat controller and you would use the fan in the highest setting and then make adjustments through the variac and not on the fan

i know almost every shop sells them for the inlines but its not what you really need 
that controller is actually a router / single speed drill ( which are both non capacitor brushed motors ) controller  that has been remarketed  

im not saying it doesnt work 
just that its not right


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## TrollMaster5000

variacs are like $60-$100 is why most people jump on the on the $20 rheostat


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## Hackerman

Hydrofarm sells this and recommends it for use with their fans. What's up with that?

hxxp://www.hydrofarm.com/product.php?itemid=8589


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## TrollMaster5000

notice where it says stall speed range eliminated to prevent stoppage 
they just made it to where it wont turn down to less then 50% or where ever the fans normally stall its still a rheostat / dimmer


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## TrollMaster5000

if you could sell a dimmer that would slowly burn out a fan 
and profit from the sales of the dimmer would you ? 
with the proper dimmer your fan will last longer and be safer to operate 
i hate to say it but there is no money in that 
and these companies know this


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## Hackerman

So, I should be using something like this...

hxxp://www.ebay.com/itm/New-VARIAC-Output-0-130VAC-3AMP-60Hz-NIB-/261479411614?pt=LH_DefaultDomain_0&hash=item3ce1632f9e


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## TrollMaster5000

yes 
your fan would last longer then with the other kind 
and it would make the motor run quieter then with the other one 
it takes away alot of the motor hum


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## Hackerman

Here is the devil's advocate. Apparently, he is against the variac...

_Originally Posted by imnotcrazy
Secondly, I was and still am adamant against the use of a variac on a permanent split phase capatitor type motor. These are the type used in Vortex, Fantech, Canfan and Eco Plus Centrifugal type inline fans.

A variac is usable on the S&P type fan, as per their technician (and I found out by looking into the fans themselves) because they use a Shaded Pole Type motor. These motors have a design that limits current through the motor windings regardless of voltage applied to the motor.

Permanent Split-phase capacitor type motors do not have the ability to do this. And the motor requires the same wattage. This via Ohm's Law means the motor pulls more current. That would be alright if the motor responded like a resistor but it doesn't. Any speed control provided by a variac is because of reduced torque, but an AC motor's speed is determined by the frequency of the applied voltage (60Hz USA).

Therefore, the motor will continue to pull more current in an overload type of situation until the motor windings burn or some protection circuit trips. Most variacs do not have a fused secondary winding and because the primary side current remains low, the primary side fuse will NOT protect the motor. This eventually creates a short circuit either in the fan motor or at the variac secondary winding.


To add, I never originally considered the S&P type fans because of their Axial design. They are much less efficient when dealing with static pressure and any length of ducting will seriously effect their performance. I wouldn't even consider using one for a carbon filter.... _


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## Hackerman

Still playing with this and I have another question, if I may.

Is the Hydrofarm Active Air ACDF6 Centrifugal fan that I am using as my exhaust fan considered a "brushless motor"?

Thanks


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## Hackerman

multifarious said:


> Go digital then



Can you be a little more specific, please? Do you mean something like the Evolution digital fan controllers you posted earlier?


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## The Hemp Goddess

Hackman, I gotta tell you that in real life, in actual practice over many years, a controller like the $20 Speedster works just fine.  I have a 6" Vortex that I have had for so many years I can't remember when I bought it (but at least 7 years ago) and have never had one bit of problem with.  I have a backup fan in the closet since I absolutely cannot be without a fan with the 1000W but there it sits, gathering dust.  Maybe this is getting a little more complicated than it needs to be?


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## Hackerman

I always make things more complicated than they need to be. Part of the illness, I guess. LOL

For 30 years, the only ventilation I had was a bathroom fan on the ceiling. LOL Worked fine.

But, like I said before, this is a hobby for me so experimenting and learning new things is part of the fun.

My CAP Speed controller has a label on it that says, "Do not use with brushless type motors". And, the inline fan I am using (and the ones we most use) are brushless motors... are they not?


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## zipflip

IF YA GOT THE COIN THEN A VARIAC IS A MAJOR PLUS over tehm chincy speedster controller IMO. I got 4 variacs . one on every single canfan I use when running.  speedsters work but ya always got tham dang hum whining sond when ya dim it down. u egt a variac and hook it up to that and all that annoyin hum and whining noise goes away. also my fans seem to last  do better on them vs the speedsters I used to use years back. after getting the first variac way back when I jumped on it and got 3 more to replace the speedsters I loved them so much. maybe odd annoyin noises that are constant don't bug u as much as me but if ur one who is driven nuts over anoyin noises and don't mind paying extra in life for piece of mind as well as performance etc then definitely opt for vaiacs. JME and opinion  on controlling speed for these inline fans.


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## Hackerman

Do you have the make and model that you use?

Thanks


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## zipflip

its actuallya  generic brand but its a smaller 5amp one is all. personally I wouldn't go less than.  just go ebay and do search for variac, u'll get buncha em. im soon to replace them in future tho with better ones. like I said they generic cheapos, and like wit everything ese I bought on the cheap I always end up replacing wit a more kosher model in fiture. but when I do im never disaponted.   the good ones aren't cheap either jus so u know. but I been runnin cheap 50$ 5am variacs all for over 4 years now. only thing ive had to do since was replace a few the carbon brushes inside, that can/do and will need replacing at some point dependin on how much u tend to fiddle wit ur knob turnin it up an down. the carboin brush thing im talkin bout u can search on youtube they got a tutorial demonstration on how to replace them. hard for me to explain is all.. but its just a simple crude soldering u got do and its easy done. just to be safe tell who ever u buy the variac from u wanna buy at least one replacement carbon brush per variac u buy. would suck to have the thing go out in middle of a grow and gotta wait for replacement to get to u is all. or if like me u can have a few speedsters layin round just for backup purposes.  
 and them brushes are only a few bucks extra is all so its inexpensive IMO.  but simply tho if ur wantin to run ur inline fans on a dimmer and lookin for the most life from ur fan with the least amount of power loss wit age of life of fan then honestly a variac is ur best bet .


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## Hackerman

I have been looking at them and reading a little.

I still don't know if these fans that we all use (like my Active Air Centrifugal) are considered "brushless motors". As far as I can tell from what I have read, they are. Anyone on that?

Thanks


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## zipflip

idk the mechanics of all inline centrifugal fans on the market but I know for fact u can trust canfan brand fans on variacs. canfan even has their own branded variac speed controller. they pitch it as manily for the maxfans as they don't accept the speedster type speed controllers.  
 don't qupote me on it but I do believe that pretty much all the standard inline centrifugal fans in the growing marketplace today are compatible with dsaaid variacs.  I know I have 4inch and 6inch canfans as well as a cheapo knockoff from ebay and another chepo I no longer use that have all been run on variacs over the years and none have faile dme yet so...  my suggestion would be to call the manufacturer of whatever fa ur using and ask them directly. or the seller even if they know.  and me personally if iasked someone I was to buy a fan from that question and they didn't kwo answer then they obviously don't know the product they sellin very well, so I wouldn't trust a word comin out any thir mouths. find one who kows. why I lean  more towards calin the manufacturer and askin.


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## Hackerman

Hydrofarm's web site says this about their fan speed controller...

_Hydrofarm's Fan Speed Controller was designed especially for centrifugal fans. This means it will help prevent damage to fan motors, ensuring longer life. (Meant for use with brushless motors, and all Hydrofarm inline fans, not booster fans)_

Sounds to me like their inline fans are "brushless". I wonder what's different about this dimmer than the other ones.

It does say that it is meant for use with their inline fans so (unless it's all marketing hype), I have to think there's something different about this speed controller than the CAP model that I have, that says, "Do not use with brushless type motors".

I wonder if I stopped smoking for a few hours if this would all clear up. LOL


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## zipflip

just cuz something doesn't kill ya doesn't mean its good for ya does it?  LOL  naw but really tho all the research ive done them speedster type controllers work. "THEY WORK"  don't mean they optimal for the life and wear an tear of ur fan. a lot of things depend like how u use it how hard u run it how much neg pressure while dimming it down etc etc... all these factors come into play when figuring fans efficiency IMO.  i'll see if I can find something I had a whiel back that explained the skinny on these variacs with inline centrifugal fans givin specs etc.  cant recall off top head but I know that a variac is still better for ur fan.  
 the speedsters are cheap cost wise and  the masses are all bout price bein cheap and so the marketplace caters to the masses where the most profit is to be had., u think they gonna push variacs more regardless if they better for ur fan or not if they know they aint gon sell hardly any. I guarantee they do and will always make more  money sellin off them cheap lil speedster type controllers cuz thas just the way things go in the world, but a variac is still better. its just not commonplace nor popular due to cost mainly I imagine. 
  dude, just get urself a variac trust me. or better yet. get a speedster and a variac and test both see wats better for u. I guarantee once u HEAR" the difference u will send the speedsters back for sure.   
 but if ur really pressed for schematics on the whoel variac wit inline fans just do some googling. its all I did back before I was clueless to tehse variacs. bottom line is I was sold into them got them and now love them. and they work with my fans.  LOL


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## zipflip

better yet, just plug into google or whatever serch engine u use "variac marijuana" and ur gonna come up wit all the info u want on all sorts a MJ related growing forums of discussions of use of variacs wit inline fans of all sizes and brands etc and explanations of everything u wanting to know. I guaranteed u'll be sold on variacs after a days worth of reading and researching.


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## MR1

Hackerman I don't think they use brushed motors in ventilation unless they are sealed because of fire hazard from the sparks the brushes give off.


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## Hackerman

zipflip said:


> better yet. get a speedster and a variac and test both see wats better for u.



That's, pretty much, my style. LOL

Thanks again for all the info.


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## Hackerman

MR1 said:


> Hackerman I don't think they use brushed motors in ventilation unless they are sealed because of fire hazard from the sparks the brushes give off.



Thanks.


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## zipflip

I bet if u run a speedster and put up wit the hum sound it causes from ur fans for few months and then get a variac ur gonna get oen fore every single fan u got. LOL  
 one thing I do recall tho is wit speed controllers like them speedsters the way it works is think of it like a sprinkler and the chord the hose yada yada. it sorts shoots the electricity out to the fan but in like some serious fast sputters, like the rate it sputters dictates the amount of flow to the fan .. idk if that make s sense but its best I can thik of explainin the whoel humming sound the speedsters cause on fans.  the variac dorta drops or raises  the voltage output to the fan  I think it is, so therefore u get a steady stream of electricity to the fan, hence the less wear and tear on fan. also with a variac I can dial my fans down to where the prop inside the fan will turn so slow I can count the blades on it while it turns . but wit a speedster its pretty lame IMO. don't run ur fan as slow as I was sayin tho its not good for it but im jus sayin. u got better precision over controlling ur fans flow wit a variac also.


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## Hackerman

OK, this horse isn't dead yet. I need to beat it a little more. LOL

New question....

Is there a speed switch that is designed to work with the little inline booster fans?


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## MR1

I am using a ceiling fan controller for my 8'' duct booster.


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## Hackerman

multifarious said:


> Please, someone shoot the horse and put it out of it's misery




LOL, really. However, if we shoot the horse, all we can do is make glue. And if we make glue, this thread will become a sticky thread. And, we don't want that now, do we? :rofl:

So, answer the question and be grateful the horse is still alive. LOL


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## Hackerman

MR1 said:


> I am using a ceiling fan controller for my 8'' duct booster.



That was my first thought. Then, I read something about those ceiling fans actually having 3 different size windings which is why those dimmers work.

You know, for a guy who reverse engineers secure hardware, I sure am stupid about something as simple as a fan motor. LOL

Thanks again, everyone for the input.


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## Hackerman

Are you saying that the digital controller has the proper electronics to speed control my Centrifugal AND my booster fan?

Most of the ones I saw just did on and off.


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## Hackerman

Actually looks like a pretty neat upgrade. I am going to shoot through the online manual and check it out.


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## Hackerman

I bought the Active Air controller that was (supposedly) designed for the Active Air fan I am using.

The only difference I see between this and the other controllers is that it starts on HIGH when you turn it on and then it adjusts to slower as you turn the dial clockwise.

Seems to be working. I run both of them at about 70%.


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## Hackerman

It's totally manual.


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## Warrior

Hackerman said:


> I have been looking at them and reading a little.
> 
> I still don't know if these fans that we all use (like my Active Air Centrifugal) are considered "brushless motors". As far as I can tell from what I have read, they are. Anyone on that?
> 
> Thanks


 

From what I understand...A brushless motor is a motor with bearings...rather than bushings/brushes.....is this correct?


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## bobkat

Warrior said:


> From what I understand...A brushless motor is a motor with bearings...rather than bushings/brushes.....is this correct?




no lol
a brushed motor typically uses carbon brushes to conduct electricity and a brushless motor doesnt :yay:


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## Tekdc911

bobkat said:


> no lol
> a brushed motor typically uses carbon brushes to conduct electricity and a brushless motor doesnt :yay:


.....................


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## bobkat

Tekdc911 said:


> .....................





:cop:


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