Help: Controlling Fan Speed Centrifugal Fan

[Bottled Cat]

Hello ICMag.
I am using a Can Fan 6" HO (Actually Can Fan brand, model RS6HO). I have tried using a rheostat type controller (like the Speedster, or the controller offered by HTG) and those cause an extremely loud (and dangerous) hum from the motor of my fan.

My question here is, what CAN I use to control the speed of my centrifugal fan? I've read about variacs, and was also referred to a product called CAP VSC-DNe.

Can anyone help me out with turning down the fan speed on my centrifugal Can Fan? Thanks ICMag.

 

[Stoner Gardener]

Help: Controlling Fan Speed Centrifugal Fan

I had the same question a while back & got pointed towards Variac controllers.
it proved to be a quick solution to fan hum
Peace ( and quiet ).

 

[Bottled Cat]

Varaics are safe to use indoors as well I assume? Do they give off a lot of heat or anything that needs to be noted of them? My fan maxes out at like 1.2Amps and I found a variac for a little under 60$ shipped that is rated at 3A. Really want to try it out...

 

[David762]

Hello ICMag.
I am using a Can Fan 6" HO (Actually Can Fan brand, model RS6HO). I have tried using a rheostat type controller (like the Speedster, or the controller offered by HTG) and those cause an extremely loud (and dangerous) hum from the motor of my fan.

My question here is, what CAN I use to control the speed of my centrifugal fan? I've read about variacs, and was also referred to a product called CAP VSC-DNe.

Can anyone help me out with turning down the fan speed on my centrifugal Can Fan? Thanks ICMag.

Avoid variacs -- they are essentially two magnetically coupled transformers which reduce the AC voltage ... reducing the voltage too far will cause premature fan motor failure, and are a potential fire hazard. OTOH, triac-based speed controllers chop the normal 120 VAC (in the USA) waveform like vertical blinds. Even triacs provide only a limited range of speed control. The best method of motor (fan motor) speed control is to incorporate multiple sets of windings in the motor itself, which unsurprisingly drives up the cost of the fan.

If you need to reduce the CFM of the fan, can you select a different fan with lower CFM ratings?
If it is a matter of fan vibration, hanging the fan from above using a rubber strap should help.
If it is a matter of air turbulence noise in the ducting, there are insulation wraps|blankets available that muffle the noise and also provide thermal isolation.
Another method would be to make use of duct reducers from 6" to 4", and use a smaller 4" fan.

 

[Bottled Cat]

Avoid variacs -- they are essentially two magnetically coupled transformers which reduce the AC voltage ... reducing the voltage too far will cause premature fan motor failure, and are a potential fire hazard. OTOH, triac-based speed controllers chop the normal 120 VAC (in the USA) waveform like vertical blinds. Even triacs provide only a limited range of speed control. The best method of motor (fan motor) speed control is to incorporate multiple sets of windings in the motor itself, which unsurprisingly drives up the cost of the fan.

If you need to reduce the CFM of the fan, can you select a different fan with lower CFM ratings?
If it is a matter of fan vibration, hanging the fan from above using a rubber strap should help.
If it is a matter of air turbulence noise in the ducting, there are insulation wraps|blankets available that muffle the noise and also provide thermal isolation.
Another method would be to make use of duct reducers from 6" to 4", and use a smaller 4" fan.

I can't select another fan for exhaust, as this is the only fan I have available to me... I am using a 250W HPS in a 2x2x5'6 grow tent.

I have my fan hanging from bungee cords as we speak, its not the vibrations that make the noise... it's the air pressure. If the fan is maxing out, or running at full speed, it sucks the walls in on the tent creating too much negative pressure.... plus the thing is loud as hell when running full blast.

Is there no way to control the speed of my fan? If I could get it to run even at 40-60% I am sure that would reduce most of the noise... and all that air pressure.

EDIT: This is the CAP VSC-DNe : http://cgi.ebay.com/VSC-DNe-Day-Nig...t=LH_DefaultDomain_0&hash=item3f02992dfb#shId

This is the variac: http://www.officebeyond.com/va-130-0300.html

I was hoping the VSC-DNe would do the trick, it costs a little more but basically would take care of everything for me. I just don't have the money right now to buy another fan... money is tight around here right now due to some medical bills, and the only reason I got such a big fan was because all along everyone was telling me I could speed control it. Just trying to supply my wife with her medicine.

 

[pontiac]

Get a Triac controller like this one; no wiring required: http://www.harborfreight.com/router-speed-control-43060.html

With a Triac, the chopping of the AC voltage WILL cause hum via electrical vibrations. This hum can be louder than the airflow itself depending on the surface the fan is mounted on. The solution is to hang the fan on bungees or mount the fan on a squishy material.

I forget exactly how, but Variacs make a fan draw more current which can cause both the fan and variac to overheat... Something to do with the nature of AC motors themselves.

 

[Bottled Cat]

Get a Triac controller like this one; no wiring required: http://www.harborfreight.com/router-speed-control-43060.html

With a Triac, the chopping of the AC voltage WILL cause hum via electrical vibrations. This hum can be louder than the airflow itself depending on the surface the fan is mounted on. The solution is to hang the fan on bungees or mount the fan on a squishy material.

I forget exactly how, but Variacs make a fan draw more current which can cause both the fan and variac to overheat... Something to do with the nature of AC motors themselves.

Are you sure one of those isn't dangerous to use on my fan? I bought one of those from HTG Supply, and it makes my fan buzz... it does control the speed don't get me wrong... I'm just worried that it can cause the fan to burn out? What do you guys think? I am willing to try anything that will work safely...

 

[pontiac]

IMHO, it's safer to use than a Variac... I was once electrocuted by a Variac hooked up to an inline fan, so I can tell you this from experience. Just hang the fan on some bungees to get rid of the hum.

 

[Bottled Cat]

IMHO, it's safer to use than a Variac... I was once electrocuted by a Variac hooked up to an inline fan, so I can tell you this from experience. Just hang the fan on some bungees to get rid of the hum.

I have my fan hanging from the bungees at the moment, but perhaps I could give them a little more slack? They are pulled pretty tight so not sure if it's helping the problem or not... although... the "humming" noise is coming from the fan only when the controller is used. It's not so much a shake or a vibration... just a really noisy buzzzzz. Is this a bad thing?

 

[darkhorse]

i have gave up with fan speed controllers, i just set up my tent not long ago
and plugged my 8 inch and 6 inch into a sms controller and what a racket
that comes from having them pluged into the sms.
as soon as i take them out of it its much much quieter and the other thing
is i think the sms stops full power going to the fans even when its needed
for example my 6 and 8 inch plugged into the sms couldnt keep the temps
down in a bud box xxl- 1.2m x 2.4 x 2m, where as before i ran a tent double the size
with the same fans and it managed the temps no bother. they were on a primair
controller that time but i had wireing isues with the primeair.
the primeair was quieter but still had issues.
now i have just got the 8 inch going full whack pulling in pasivly and its managing ok.

 

[pontiac]

Buzzing happens in my fan too, but i fixed that by mounting it on squishy foam. Try different ways to suppress the noise... maybe use more bungees?

 

[Highlight]

Deleted

 

[Bottled Cat]

I just wired up a Hunter 3 Speed Ceiling fan switch through an outlet, and it controls the speed of my fan without a hitch. The only reason I come here asking for another way to do this... is because well High speed is too high and noisy... but Medium and Low both run at the SAME speed which is barely running at all.

Maybe I can try a 4 speed ceiling fan switch? It seems like all fan controllers are either dangerous or just don't work that well at all.

 

[Bottled Cat]

WTF I use a HTG fan peed controller. Dangerous? Is there something I should know about? Please elaborate for my sake.

I would like to know all the info on this too... I really would LOVE to use it but I do NOT want to burn out my fan. I cannot afford that right now.

 

[rick shaw]

You won't be the first one here to buy to much of the wrong thing.Your space 2x2x5.6 is 22.4 cubic feet a bathroom exhaust fan would be adequate, about $40 at Lowe's. Park that fan until you upgrade,when you do that cute lil tent can be for mom. A 6"can fan HO can do a circus tent or a small room. .

 

[Bottled Cat]

You won't be the first one here to buy to much of the wrong thing.Your space 2x2x5.6 is 22.4 cubic feet a bathroom exhaust fan would be adequate, about $40 at Lowe's. Park that fan until you upgrade,when you do that cute lil tent can be for mom. A 6"can fan HO can do a circus tent or a small room. .

You know... I was just basically thinking the same thing. Can you link me any specific (quiet operating) products that would work well with cooling my tent? Carbon scrubber will be added on in the future as well.

I wonder if I could sell my current fan anywhere? The only thing I could think of was a pawn shop... and damn... who knows what I would get from them. I should of just got a damn squirrel cage blower... aren't those speed controllable with those cheap speed adjusters?

 

[rick shaw]

If your broke put it on CL it's worth $100. In the DYI section theres a couple of threads for a fan and charcoal filter set up.

 

[Bottled Cat]

Just put it on Craigslist... hopefully someone will be interested. Think it's worth a shot taking it to a pawn shop to see what I can get out of it? A local hydro store carries some inline fans... but I think I might try a squirrel cage blower/dayton blower. Do those operate pretty quietly? And can I use that HTG/Speedster controller on those? Was gonna pick up the 265CFM model if I can sell this other fan.

 

[Bottled Cat]

I'll bump again in the morning, I gotta get some sleep.

 

[Bottled Cat]

bump