fan speed control

borbor

Well-Known Member
I was stupid last month when I bought one of my fans and bought a "speedster" fan speed controller with it.
since then I've read a lot of different confusing things about this.
Will this work with either of my two fans well?
People say the motor will hum, and the life of the fan is reduced, but then I see somebody in this thread at icmag saying using variacs can be a fire hazard. Their logic makes sense to me, but maybe that's just me not wanting to spend 30% more on ventilation just to control the fuckin' speed.
 

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crawlintbss

Well-Known Member
itll work.

i have it with no problems on my ventech inline fan. ( like the green one in your pic ) no problems here. if you try and run it super low youll get a humm cause its not enough voltage but i have mine at 50% ith no problems. if you add a baffle or long length of hose after the fan then it wont be too loud but mine vents out the tent after like 8" of duct, so its pretty loud ( sound of the air running, not fan itself )

In the end i believe it just raises and lowers voltage , thus causing speed to change. if either fan have 3prong cords then it should work.
 

borbor

Well-Known Member
awesome thanks man. So I have the active air set up as the exhaust fan and the vortex s line as intake, I'm thinking since the s line is so quiet as it is, my best bet to reduce noise while keeping negative pressure in the tent and maximum airflow would probably be to switch them so that the s line (347 cfm) is used for exhaust and the active air (400 cfm) is used for intake with the speedster, so I could just plug both in and then dial down the intake until the tent sucks in.

seem legit?

Buying my carbon filter tomorrow, probably gonna go with the can 66 over the can 50, should I expect a world of difference in noise when I attach that?
 

crawlintbss

Well-Known Member
id run the inline ( green ) as your exhaust. more powerful and what its intended for. i have mine pull thru the filter and then out the tent. my 400w hps has a cool tube i could hook up but its winter here so its helping keep the tent temps level.

Not to sure what you mean by can66 vs 50. just make sure the scrubber filter cfm is larger then the fan you are running or else you are causing a restriction and putting more load on the fan, thus causing it to burn out quicker.
 

borbor

Well-Known Member
Word.
major bummer with my setup, been trying to think of a way to work around it but can't really. Using a secret jardin DR90 (3x3x6) with a sun system lec 315 as the light. The ballast is built into that light, so it's like 20 pounds itself. The DR90 specs and stuff all say it can hold 65 pounds, but the filters I'm looking at are all around 45 pounds, so I'd be right on the limit which I wouldn't get close to doing in the first place, and since the filter is gonna pack on weight as it's used, hanging the filter in the tent seems like an absolute hellno, correct? Was gonna have it on a table next to the tent with about 3 feet of ducting up to the exhaust. I know that's not ideal but I'm working with what I have for now.

a decent sized tent will happen sometime this year for sure, as well as a light with a separate ballast, all in time.
 

crawlintbss

Well-Known Member
shit i dunno what the weight limit on mine is but i have filter, fan, hps and another fan all hanging from above. its only like 1/2" tubing too. I have a 3x3x6 as well but made by Apollo.

Its not like the parts are moving or you are constantly moving the tent. if you move the tent id advise removing first but as long as its supported above i tihnk youd be okay. mine has the regular square plus 2 movable braces going one way and 1 going the other.

though you are hanging a 6" fan and larger filter then me. i have a 4" 200 cfm setup for my 3x3. that already does like 4x the air flow which is enough for me. fan at 50% still has enough neg pressure. anymore and i cant keep the tent warm enough.

IMG_20141118_234209_342.jpg inline is in the corner facing forward.
 

bravedave

Well-Known Member
Research? Where?
If I am not mistaken @crawlintbss is mistaken. Your controller does not control speed by controlling voltage...while variacs do. Yours controls speed by applying power and un-applying power (box/pulse wave) so one can certainly imagine it being harder on equipment than variacs. Please share the fire hazard link. I think it BS and at the most no worse than a box-wave unit.
 

borbor

Well-Known Member
Research? Where?
If I am not mistaken @crawlintbss is mistaken. Your controller does not control speed by controlling voltage...while variacs do. Yours controls speed by applying power and un-applying power (box/pulse wave) so one can certainly imagine it being harder on equipment than variacs. Please share the fire hazard link. I think it BS and at the most no worse than a box-wave unit.
https://www.icmag.com/ic/showthread.php?t=237552&page=3
somewhere in that thread while they're talking about dude getting shocked by his variac
 

az2000

Well-Known Member
Will this work with either of my two fans well?
People say the motor will hum, and the life of the fan is reduced,
@bravedave is correct. The inexpensive $20 dimmer-like controllers simply clip the AC sine wave, switching the power on/off 60 times per second. You don't have to turn the speed down far before you'll hear a difference compared to a $60 variac.

The $20 dimmers won't work on inexpensive brushless fans either. Fans like inline duct "booster" fans, small clip-on fans. You might not ever want to use one like that, but it helps to understand that there is a difference in the type of motor. When you read reviews on Amazon for the inexpensive dimmer control, some say "wouldn't work, fan was either on or off." They're talking about that type of fan.

The $60 variac maintains a clean sine wave. It varies the voltage (the potential available to the fan).
 

a senile fungus

Well-Known Member
Can anyone recommend a good variable speed controller that will ramp up the fan to exhaust heat then return the fan to an idle setting?

Is that a thing or am I high?
 

crawlintbss

Well-Known Member
ah my bad i was flip flopped on the 2 types. Never really researched much on them as i knew the one i bought would work.

senilefungus almost sounds like you want a thermostat to like change the speed up when temps increase. id love something like that as well.
 

Drumfounded

Well-Known Member
Can anyone recommend a good variable speed controller that will ramp up the fan to exhaust heat then return the fan to an idle setting?

Is that a thing or am I high?
Definitely a thing. Search amazon or htgsupply for thermostat controller or temp controlled outlet or something like that. They're fairly easy to find.
 

az2000

Well-Known Member
Do you know the method used by that device to slow the fan? Based upon the size/appearance, I think it's the same "clipping" as the inexpensive dimmer-like controllers.

A few months ago I considered how to make a controller for my Variac. I found a nice thermostat (Stego). Using that with a relay should work. This thread caused me to document what I was considering. It's here: Thermostatic controlled exhaust fan using a Variac.

If anyone has electrical experience I'd appreciate feedback whether the diagramed circuit is the correct way to do this.

 

a senile fungus

Well-Known Member
Do you know the method used by that device to slow the fan? Based upon the size/appearance, I think it's the same "clipping" as the inexpensive dimmer-like controllers.

A few months ago I considered how to make a controller for my Variac. I found a nice thermostat (Stego). Using that with a relay should work. This thread caused me to document what I was considering. It's here: Thermostatic controlled exhaust fan using a Variac.

If anyone has electrical experience I'd appreciate feedback whether the diagramed circuit is the correct way to do this.


I'm not sure if does the clipping but reading the comments it looks like one gentlemen was able to turn his fan down without worrying making it hum like the speedster would, which leads to me to believe this one doesn't do the sine wave clipping...

His review says he was able to slow down his fan without making the humming noise, I'll look for other reviews/info
 
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