On Aug 23, 2:41 pm, Andy Hall wrote:
On 2007-08-23 12:32:42 +0100, Mr Uncalled-For
said:



On Aug 23, 12:17 pm, Andy Hall wrote:
On 2007-08-23 11:23:01 +0100, Mr Uncalled-For
said:

I got a Vent axia 'Centrif 250' 100mm fan for my kitchen in my
previous house.
Noisy, but powerful. I was selling the place, otherwise I'd have been
really disappointed in the level of noise from the thing.
http://www.vent-axia.com/products/do...ntrif-info.pdf

Centrifugal fans are always noisy. You are trading performance for noise.

Generally, a 100mm fan is too small for a kitchen anyway - far better
to use a larger axial model and a 100mm axial model for a bathroom.

I was aiming for an extraction rate to meet building regulations. IIRC
the fan was referred to as quiet in the ad.

You do have to look at the sound ratings in dB. Vent Axia's fans
are quieter than most, even the centrifugal ones because the mechanics
are properly designed and finished and decent bearings are used, but
centrifugal fans are by definition noisier than axial ones.

It replaced a smaller fan that was less powerful, which connected into
a fairly small hole to a long duct.

Unfortunately if you have a long duct, an axial fan may not work well
anyway and it's in those cases where centrifugal fans are used.

Yeah I forget the research I did, but I believe the oomph of a
centrifugal was needed.
In the end the surveyor didn't even check the fan, so I could have
just left it as was!