Mixed-flow extractor-fans

[mointainwalker]

Hello

Posted this on Plumbing but no replies. Hope you can help.

Contacted an e-Bay vendor about some fans ( for shower-room , 8.5 m3, 4 lm smooth 100 mm PVC pipe to exterior)) and he said they were of the above type which is a hybrid of radial and centrifugal.

What I have looked-up is all related to industrial-type fans , nothing on domestic, so I would like to ask your opinions. The volume of air displaced was more than I needed, just question about the length of exhaust.

Vendor was a bit vague which seemed to be lack of knowlege rather than not wanting to say.

thanks in advance

 

[stem]

Traditionally, axial fans are used where there is a direct route to the outside, such as a window or wall or short lengths of ducting (1 or 2 metres max.) Centrifugal fans generate a higher pressure and are used with longer lengths of ductwork to overcome the losses as a result. Centrifugal fans are often physically larger, and I believe (someone else may be able to confirm or refute this) have larger motors than axial fans for a similar extraction rate.

Mixed fans have blades that use both principles and fall between the two in terms of performance. I would expect a mixed flow fan to cope with 4 metres without any difficulty. The manufacturer should be able provide data with performance figures and many can be found on the internet if you search.

 

[Taylortwocities]

Do you not have Le Google in France?

It is very good, you should try it....

I got this in 0.000000001 of a second

http://www.engineeringtoolbox.com/fan-types-d_142.html

 

[electronicsuk]

I bought a pair of inline extractors off eBay a couple of years ago, and the seller had provided a graph of extraction rate vs pressure/duct length on the listing. Perhaps you could try asking your seller to have a look through the manual and see if this information is in there or, failing that, buy from a source that is willing to supply you with the technical information you require.