DIY Silenced fan safety questions

Hi all

I have used a few "silenced" and acoustic fans, some I have found better than others..And there is still lots to try in my en devour to find the quietest and best

IME it seems that the manufacturers have an issue getting the smallest fans quiet

Some have poorly matched speed controllers that hum like a agry hornet at any speed other than full while others have foam linings that foul the blades and make a loud squealing as a result...I only need this to vent a small space with CFL lighting so it needs to be small!

I'm just messing around with things I know little about, It's gonna be a series of random questions starting with

1/ what type of speed (voltage?) controller is this

2/ What type of fan (single-phase permanent capacitor motor?) is this

3/ can they be used together

4/ Where should the plug in RCD be fitted to ensure functionality but also so as it doesn't trip all the time (after the speed controller?)

5/ If I wrap the fan in insulating set up as mentioned above will it cause it to overheat...For that matter is there any risk of the speed controller overheating?

6/ This one is a answer for you..Yes I'm paranoid, Helps me do things properly though

This is the type of silencer I used for the body, not sure on the brand but I needs to be ridged.




Here is what it looks like held together loosely, I used egg crate acoustic foam to wedge the fan in with



Still need to drill a hole (pending safety report) for the wire and put a grommet in there.

This thing is real quiet, quieter than any other fan I own...Small ducting run and small space only though.

Peace



S.S

Just an FYI, 2-3 feet of insulated ducting silences almost as well as real silencers without any reduction in airflow.

I really like this idea of capsulating the fan inside a silencer. Does it silence the motor noises well? That is my main issue to be honest, the fans themselve make shitty noises especially with speed regulators.

ChasingGreen said:

Just an FYI, 2-3 feet of insulated ducting silences almost as well as real silencers without any reduction in airflow.

Click to expand...

Thanks for the heads up bud, I always use the insulated ducting...Standard procedure

@omgwt

There is fans out there (phresh,airforce, S&P) that have the fan assembly in a silencer but they cost a bit and were all far too large for this application (small PLL mother room), it silences the motor noises extremely well.

I used acoustic egg crate foam to pad out the gap between the outside of the fan and the inside of the silencer and this seems to reduce the motor noise / vibration transferred to the silencer.

Peace

S.S

How many actual CFL watts are you using? I'm not talking about the "equivalent" watts or other useless value, how much will they actually pull from the wall? If it is under about 100 or 150 watts, consider computer fans. They are reasonably quiet and they are small. It depends on the length and type of your exhaust duct because computer fans don't have the greatest static pressure performance. If you only have to move air from one side of a wall to the other, they work well.

More fans running at slower speed reduces noise. Two computer fans running at six volts has half the noise (or less) as one computer fan running at 12 volts. Of course, they should be in parallel and not in series to get the same cooling power.

(BTW - I also assume you have reasonable temperatures for your intake air. Something around 70*F should be good. It all depends on intake air temperature, desired grow temp inside the box, actual wattage of your CFL and other equipment in the grow zone, and actual CFM of your fans.)

-r2k

The lighting I use in here are 110W PLL's on paper the actual draw is 111-111.8W so I'm guessing these high frequency ballasts are really efficient

Runs between 110w-220w depending how much is in the space.

The ducting is as you say too long for pc fans!

Peace

S.S

silencers are easy to make a few simple tools and shit from homedepot....I once bought 4 at 99$ each and after looking at them laughed and said ..your a dumbass trout...yeehaw

I only spent £30 on mine, yes it would be simple to make

Peace

S.S

ya 2 reducers, the body,,,wire screening for inside and foam..yeehaw simple as hell.. I got a rivet gun already..