Axial Wall fans a Serious noise issue - DIY-ing?

I installed my ventilation today to go with my cooltubes, and as it stands I have 2 125mm Domus extractor fans, one for each grow room (one is vert, the other horizontal, just to compare results).
When I flipped the switch however the roaring that ensued was something I wasn't prepared for. It's as loud as a Loud bathroom extractor fan (which is, after all, what it is) but this is a problem, as a) there are two of them and b) the grow set-up is in my bedroom. I'm giving the company a ring tomorrow to see if there's some simple way I can reduce the power that gets to them (no adapters, they're running straight off British monster 240 voltage) by including resistors in the circuit, etc. But I wanted to sound out the seasoned Rollitup crowd for a tried and tested method of doing this...?
Please help, it's 2:30 AM and they are Fucking loud.

Well, if you do a search on this there are several threads involving reduction of noise. To save you the time, I'll list a few of them here:

1. One way is to reduce the power supply. The Speedster Fan Speed Control | is a common one used in the states. I don't know what would work for your UK power supply. Go to a hardware store, or your local hydro shop and ask. They will know what's up.

2. Get a duct muffler. Or build one. If the noise is from a rushing of air, which is almost always nearly half of the noise, then this will reduce it.

3. insulated ducting also works for similar reasons as the duct muffler will.

4. Using bungie cords to hang the fan with will reduce alot of the rubbing and vibrating that the fan makes when it comes into contact with the wall.

5. Some people have put the fan in a box, and filled it with foam or packing material, then attached the box to the wall. This usually cuts down on the noise.

6. Look into sound reducing material. Dynamat and Fatmat works well in my opinion.

7. If none of these work, look into getting a better fan. Vortex fans are fairly common around here, but are somewhat noisy. Sunleaves fans are suposed to be more quiet, but I don't know from personal experience. I use S&P Mixvent fans, and they are amazingly quiet, in my opinion.

I hope this helps, and I'm sure there are other ways, but I'm drawing a blank right now.

thanks for the breakdown man, i was hoping for a quick-fix solution but i guess i better do some digging around eBay... i'll look into your vent system and see how much it sets me back (setup only just finished and it's taken a toll on my current account) because the decibels these things are throwing out are taking the piss..

Soler & Palau Commercial Centrifugal, Axial, Propeller, Exhaust and Supply Fans - Soler and Palau - HVACQuick.com

That's the cheapest place I have found that has the fans that I use. I have the TD 125. I must say though, I would probably recommend all of the other alterations before you buy a new fan.

a fan speed controller / dimmer running at 75% will cut the noise down drastically as will hanging the fan from bungee cord.
these 2 things should put your noise level where you need it without compromising heat. if need be you can wire a speed controller and timer in parallel so that it runs at full speed for the part of the day when its ok for the noise to be louder ... if there is such a time.
i believe there is a thread on how to do this with a thermostat but you can replace a timer for the T-stat using the same wiring diagram. so that when the timer is off the fan runs thru the speed controller. and when the timer kicks to the on position it bypasses the controller and runs full speed

I'm going for a dimmer + bungee cords, should sort the problem out with no ridiculous costs - might DIY the resistor - keep your eyes open on the DIY sub-category gentlemen lol
*edit*

I just realised 4mm silicone tubing should be just as adequate as the shock cord, anyone thought of this before? i'll post results anyway, should be done by tonight..

just to follow up, i hung the fans with standard 4mm silicone tubing (about 5cm of it) and the angry grinding roaring noise that emanated from my suspicious-looking wardrobes is down to a low, sexy hum. Well recommended, i won't even need a dimmer now. Thanks guys...

Nice, great thread!

Phinxter said:

a fan speed controller / dimmer running at 75% will cut the noise down drastically as will hanging the fan from bungee cord.
these 2 things should put your noise level where you need it without compromising heat. if need be you can wire a speed controller and timer in parallel so that it runs at full speed for the part of the day when its ok for the noise to be louder ... if there is such a time.
i believe there is a thread on how to do this with a thermostat but you can replace a timer for the T-stat using the same wiring diagram. so that when the timer is off the fan runs thru the speed controller. and when the timer kicks to the on position it bypasses the controller and runs full speed

Click to expand...

I am really interested in finding out how to wire a timer and a speed control in this fashion!!! Is it possible to use these 2 items -->

http://www.bghydro.com/BGH/itemdesc.asp?ic=AFAGS&Tp=

http://www.bghydro.com/BGH/itemdesc.asp?ic=TIBA&eq=&Tp=


Any help is much appreciated!

-