Speed Control for inline fan? No Hum!

I have a S&P 200x. I tried using the speedster controller, but causes a horrible humming noise louder then the fan itself.

I tried a hunter 3 speed fan control, and high works fine, but the med/low are both super super super slow speeds...barely moves any air!

Any suggestions on a speed control?

+rep

I bought a $10 dimmer switch from Depot. I had to slap on a 3-prong- adapter, but it works perfect!

http://www.homedepot.com/webapp/wcs/stores/servlet/ProductDisplay?storeId=10051&langId=-1&catalogId=10053&productId=100001525&N=10000003+10401001



good luck!

I think it's the fan itself that makes the hum when you cut back the power.

UserFriendly said:

I think it's the fan itself that makes the hum when you cut back the power.

Click to expand...

I think so too, because I have the exact same problem with the S&P 150. It sounds like the fan is out of balance at really low speed, like it's balanced to run only at a high speed. I just go ahead and run it full speed, because I'm worried about the bearings. I'll probably get around to calling the company next week, and see what the have to say about it. If I do, I'll post it in this thread.

Why do you need a fan controller for an S&P? It has two settings, low and high, already on it.

WhatWouldBobDo? said:

Why do you need a fan controller for an S&P? It has two settings, low and high, already on it.

Click to expand...

I need to slow it down a bit more to decrease noise..

WhatWouldBobDo? said:

Why do you need a fan controller for an S&P? It has two settings, low and high, already on it.

Click to expand...

I can't speak for the other guy, but personally I was trying to see if I could get it even quieter by cutting the speed down a bit. It's already an extremely quiet fan, but I was just curious to see if I could get it down to the point of almost being silent.

And, from a more practical standpoint, we're using this in a basement grow, in a climate that gets pretty cold in the winter. Even at the lower setting, the fan still draws a lot more air than we need it to for odor control, and I'm somewhat concerned that it'll draw too much cold basement air into the grow room during the winter and make it more difficult to keep the temps up. I vent straight up the chimney, and this far north that means that the lower your fan speed, the less money you're pouring up the chimney each day. I'd like to vent no more air than I actually need to, if it's possible.

I had this problem since the beginning of my grow, after one year I settled on this (see pic) it most certainly works with absolutly no electrical humming from the fan or controller, these are the features:

• Suitable for fans up to a full load current of 1.5 Amps.
• Completely eliminates noisy motor hum!
• Surface mounting with cable glands.
• Excellent for hydroponic grow room fans.
• Brand new, in box with full wiring instructions!
• Genuine product with 12 months warranty.
• Reduced fan noise, fans speed and power consumption.
• 5-Step speed control.
• Protected to IP54.
• 2.2 & 5 Amp versions also available for bigger fans.
• Discounts for trade customers and bulk purchases.
• Works with ALL major fan brands!
• VAT Invoices available.
• Green "on" light.

Im not sure if its availabe in the country where you live in but the manufacturer is "STR" google it.

I know this doesn't really help your situation, but if you are trying to reduce the fan even lower than the lowest setting, either to reduce noise or to reduce air flow (or both) it sounds to me like you got the wrong fan. If you need to move 100 CFM, you should get a fan that moves 100 CFM. If you get a fan that moves 150 CFM, you have the wrong fan. AT least in my opinion.

I'm not trying to be rude, although I know I sound like it, I'm sorry. I just think you should really try to get the right part first, then try to modify it. If you got the wrong part, there is your problem.

I've had alot of success with S&P's using duct mufflers, insulated duct work, diffusers, bungee cords, fat mat, packing foam, and insulation. That helps out with alot of the noise, both with air flow, and the hum of the fan. With S&P's, my experience has been that the majority of the noise you get is from airflow, not from the hum. Which you can mask and do everything you can to cover it up, but when it comes down to it, if you need to move 100 CFM through a 6" hole, no matter how much you modify it 100 CFM is still going through that 6" hole.

Just a thought though.

Yes you might need a weaker fan but you could try duct damperer or diffuser. With the money you've spent you probably could have almost paid for a new fan.

WhatWouldBobDo? said:

I know this doesn't really help your situation, but if you are trying to reduce the fan even lower than the lowest setting, either to reduce noise or to reduce air flow (or both) it sounds to me like you got the wrong fan. If you need to move 100 CFM, you should get a fan that moves 100 CFM. If you get a fan that moves 150 CFM, you have the wrong fan. AT least in my opinion.

I'm not trying to be rude, although I know I sound like it, I'm sorry. I just think you should really try to get the right part first, then try to modify it. If you got the wrong part, there is your problem.

Click to expand...

Oh, you're not being rude. It's a sensible point. I decided to get a fan that was a little bigger than needed for a couple of reasons. First, I'd rather have too much fan than not enough, especially in case I decided to go with a carbon filter down the line. Second, I had a brilliant scientific theory that a larger fan running at extremely low speed would be quieter than a smaller fan running at a higher RPM. And i wanted to try that out. But I have failed.

Either way, it's not that big of a deal. I'm happy with the choice; I just always like to tweak things. If i can't tweak it as much as planned on tweaking it, I'm still perfectly happy with it. It's a terrific fan, and I'm really glad to have it.

Look into Variac transformers.
They supposedly are much better than the "Speedster" types of controllers for eliminating that hum from the fans.

I on the fence about ordering one.
It's 5 times more than I paid for the generic from Harbor.
Then again, it may extend the life of the fans.
Someone posted, at a competitors site, that the cheaper controller operated by constantly interrupting its power source.
A series of cold starts. "It's like turning a light bulb on and off really fast; eventually, that bulb will burn out."

If it doesn't work, one could return it.
http://www.circuitspecialists.com/prod.itml/icOid/7674
Good Luck!

here is the one i use http://www.plantitearth.com/environmental-control/the-speedster-grounded-variable-speed-controller.aspx its variable and i have no problems with it, no hums or anything

I purchased a bigger fan because down the road I will need the higher CFM. The fan is made to be controlled by a speed control so no reason not to use it =p

Sorry to ask but a diffuser opens only when you have the fan on? and closes when the fan turns off

No that's a backdraft damper.

The cheaper speed controllers to operate in pulses which are a series of coldstarts. This is hard on the motor and the hum is an audible sign something is wrong. The more pricey models of controllers offer a different method which won't harm the motor. Fwiw, S&P do not reccomend speed controlling any of their two speed fans. If the low setting is too high, you need a smaller fan. If the fan is making noise, it is masked by insulating it in a box. If the air is making noise at intake or exhaust, mufflers can be made or purchased. If it is air through the ducts then either hard plumbing or using insulated duct. I myself am a big fan, no pun intended, of buying a fully speed controllable fan that is too large, and using a quality speed controller. It offers much more flexibility though costs more. LD

sounds like it not a speedcontrolable fan, prob isnt safe . invest in a new fan my friend.
cheers

iloveit said:

I had this problem since the beginning of my grow, after one year I settled on this (see pic) it most certainly works with absolutly no electrical humming from the fan or controller, these are the features:

• Suitable for fans up to a full load current of 1.5 Amps.
• Completely eliminates noisy motor hum!
• Surface mounting with cable glands.
• Excellent for hydroponic grow room fans.
• Brand new, in box with full wiring instructions!
• Genuine product with 12 months warranty.
• Reduced fan noise, fans speed and power consumption.
• 5-Step speed control.
• Protected to IP54.
• 2.2 & 5 Amp versions also available for bigger fans.
• Discounts for trade customers and bulk purchases.
• Works with ALL major fan brands!
• VAT Invoices available.
• Green "on" light.

Im not sure if its availabe in the country where you live in but the manufacturer is "STR" google it.

Click to expand...

these are the the dogs nuts . and will give no fan hum what so ever i changed over to using 3 of these on my set up about 18 months ago and
there well worth the money.

growem green------------------spike

rotcodnatas said:

Yes you might need a weaker fan but you could try duct damperer or diffuser. With the money you've spent you probably could have almost paid for a new fan.

Click to expand...

most fans make noise due to the harmonics of lowering the voltage to windings in the motor thereby slowing the speed of the rotor, (thus 2 speed operation = hi and low). By reducing the voltage other than what the motor has been designed for (low speed selected on motors wiring or switch and then trying to slow the motor further by a dimmer rated for the current draw ) is not how the motor was designed to run. It causes the rotors efficiency to go down. in creasing the current through the windings and adding harmonics due to running the motor this way. The problem I see is that some motors that are 2 speed need to setup to high or the higher selection and tried through a motor rated dimmer or controller.

Another possible fix for some might be a larger filter to help reduce pressure, flexible insulated duct, remove as many hard and or bends that are close together as that will decrease drag and noise, and try to insulate the ducting, fan, filter, from structural supports by flexable hangers such as nylon straping, tyraps, short runs, etc.

Hope this helps as I dont think you want to replace a fan motor due to " burning it UP" by not using it as it is rated.

Peace out

rotcodnatas said:

Yes you might need a weaker fan but you could try duct damperer or diffuser. With the money you've spent you probably could have almost paid for a new fan.

Click to expand...

most fans make noise due to the harmonics of lowering the voltage to windings in the motor thereby slowing the speed of the rotor, (thus 2 speed operation = hi and low). By reducing the voltage other than what the motor has been designed for (low speed selected on motors wiring or switch and then trying to slow the motor further by a dimmer rated for the current draw ) is not how the motor was designed to run. It causes the rotors efficiency to go down. in creasing the current through the windings and adding harmonics due to running the motor this way. The problem I see is that some motors that are 2 speed need to setup to high or the higher selection and tried through a motor rated dimmer or controller.

Another possible fix for some might be a larger filter to help reduce pressure, flexible insulated duct, remove as many hard and or bends that are close together as that will decrease drag and noise, and try to insulate the ducting, fan, filter, from structural supports by flexable hangers such as nylon straping, tyraps, short runs, etc.

Hope this helps as I dont think you want to replace a fan motor due to " burning it UP" by not using it as it is rated.

Peace out