Fans

[MDE]

Hey guys,

So I have some equipment in a cupboard with a 12v ventilation fan running. The 12v fan is connected to a 9v supply in order to reduce the rpms. The thing is its still running to loud.

Does anyone know of a quieter fan.

Thanks.

 

[psion]

The bigger the fan the quieter it is. It all depends what you have space for? Also insulate the fan with rubber to absorb vibration going to your wooden cupboard.

 

[kayvee]

Running a 12V fan at 9V is not the solution to the problem.

Fans have inductive motors, and are designed to run at the rated voltage, so lowering it will not fix anything.

Look around for a "silent" replacement and run it at the rated voltage. Checking the datasheets can also reveal the naise rating (dBa), the lower the better. Airflow is also something to take into account.

 

[ponder]

You need a bigger fan running at lower rpm.

Look at http://www.ebmpapst.co.za/en/products/overview.html they have dB ratings for noise.

 

[MDE]

Thanks will give a look.

 

[SouthBit]

Or place the fan inside the cupboard with ducting that runs to the outside, then you've got the noisy fan inside and not on the outside of the cupboard. Sure, you'll still hear it, but you'll get rid of some of the noise.

And +1 to bigger fan @ lower RPM.

 

[MDE]

Or place the fan inside the cupboard with ducting that runs to the outside, then you've got the noisy fan inside and not on the outside of the cupboard. Sure, you'll still hear it, but you'll get rid of some of the noise.

And +1 to bigger fan @ lower RPM.

Cool. Actually managed to get things sorted this past weekend.

1. Fans is situated inside the cupboard.
2. Larger fan at lower RPM.
3. Bought a fan that had super silent on the box and checked the noise level in the store.

Now I can't here the fan at all.

 

[kayvee]

Great work!

 

[Batista]

Expander foam is your friend

 

[P924]

Fans have inductive motors, and are designed to run at the rated voltage, so lowering it will not fix anything.

Look around for a "silent" replacement and run it at the rated voltage. Checking the datasheets can also reveal the naise rating (dBa), the lower the better. Airflow is also something to take into account.

Hmmm, dc fans have BLDC motors with hall-effect sensors, so lowering the voltage does lower RPM.

 

[kayvee]

Hmmm, dc fans have BLDC motors with hall-effect sensors, so lowering the voltage does lower RPM.

Whilst your observation is correct, the proper way to apply speed control is with PWM, rather than a voltage jippo, because that is all it is. One has no way of knowing exactly how the internal controller is configured/designed, and these can vary considerably.

 

[grim]

Cool. Actually managed to get things sorted this past weekend.

1. Fans is situated inside the cupboard.
2. Larger fan at lower RPM.
3. Bought a fan that had super silent on the box and checked the noise level in the store.

Now I can't here the fan at all.

Which fan did you buy?