Noisy fans Vs Quiet Fans..

[joachimsim]

Hi bros,

I need some advice on this.

On my Marine tank I use a 12 V 0.12 A ( I think ) AC fan I found while rummaging thru my old stuff..it used to be for my VCR. It seems quite quiet.

I recently acquired an Aista Fan at $40 ...it has a wire grill for finger protection. It is also 12 V for current rating is slightly higher.

But the problem is the latter is quiet noisy...to the ears...I WONDER is it cos of the grill or the brand /Type of fan.

I realise while shopping along Sim Lim that AC fans can range from $30 to only $12...and I think I read brushless motors etc..


Can anybody tell me the difference...??

[Bond]

Hello
A fan that has carbon brushes and they ride against a armature made out of brass,as the brushes ware down, the metal that is holding the brush may be touching the armature of the fan and the fan becomes more noisy or brushes get so bad it won't run.

A fan becomes noisy if the blade is bent a little. Throwing the fan blade or prop out of balance[ check it it could have hit the guard at one time or another,and still maybe rubbing as it may touch it if it is off balance.

Now the blade or prop on the shaft is to far out on the shaft from housesing causing it osulate in and out also bearing in rear of fan is worn and letting shaft travel in and out.

Now to the motor that dosen.t have brushes.Must have something like a printed circuit board or a set of points, this is a guess on my part.Sorry.

Later Bond

[vinz]

The Aista fan should be quite easy to remove from the clip and replace. Go to Sim Lim Tower and shop around for a similar sized fan. Some shops will let you test before you buy.

My experience with DC fans, for tolerable noise:
- 12cm fans, do not exceed 0.33A
- 9 and 8cm fans, do not exceed 0.25A

It may vary with brands. I'm using NMB. No experience with AC fans.