Choosing the right type of replacement extractor fan?

[Tezza2k]

When I had a bathroom refurbished 5 years ago by Dolphin Bathrooms they replaced my old 100mm fan, which runs by ducting to the roof, with a Silavent PVS 100TBS axial fan (p.15/16 of the document at: www.silavent.co.uk/pdfs/section_02.pdf ) which worked reasonably well and wasn't too noisy.

• Extract Volume : 85 m3/h
• Sound Volume* : 29.0dB (A)@3m
• Voltage : 230-240v AC~
• Frequency : 50 Hz
• Wattage : 11W
• 155mm x 165mm
• Max Pressure : 33 pa

The fan has now stopped working (although the automated shutters still open/close in accordance with the timer settings). I’d like to get it replaced by something similar but Silavent no longer make this model or seem to be able to suggest an alternative to fit the same size recess and suitable for use with ducting.

I don’t know enough about fan performance to recognise what would be suitable for my needs. I've looked at the Vent Axia VA100XT Axial fan (eg. www.diynot.com/shop/Ventaxia_Va100XT_Fan/18859 ) as a possible replacement.

• Extraction Rate 90m³/hr
• Noise Level 31dBA at 3m
• Auto Shutter
• Width: 155mm
• Profile Depth: 44mm
• Timer: Max. 25min

Could someone advise if this or maybe another fan would be ok for a straight swap please?

 

[foxhole]

Most surface mounted 100mm fans would fit the existing hole, example http://www.screwfix.com/prods/62530/Heating-and-Ventilation/Extractor-Fans/Manrose-Gold-Timer-Fan-4
But rarely a straight swop as incoming power access may be in a different place and fixings vary but simple to modify.

 

[Tezza2k]

Most surface mounted 100mm fans would fit the existing hole, example http://www.screwfix.com/prods/62530/Heating-and-Ventilation/Extractor-Fans/Manrose-Gold-Timer-Fan-4
But rarely a straight swop as incoming power access may be in a different place and fixings vary but simple to modify.

Thanks for the advice Foxhole. I also need to make sure the VentAxia or the Manrose you suggested are suitable for use with a run of ducting rather than window/wall extraction. Do you know if they are?

 

[^woody^]

You should use a centrifugal fan with ducting - not an axial fan.

Most fans at particular price points are much the same, but the key things are higher extract rates (m3) and lower noise levels (db)