Speed Control for inline fan? No Hum!

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/...00003+10401001



good luck!

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

Originally Posted by UserFriendly

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

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.

Originally Posted by WhatWouldBobDo?

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

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

Originally Posted by WhatWouldBobDo?

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

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.