Extractor hood -pipe-sizing and possible noise

[mointainwalker]

Hi all

In the house I'm renovating, I've put up the plasterboard in the kitchen and , since I will be having an extractor hood, put in 4 m of 100 mm PVC pipe behind the pb as the vent for the - as yet -unselected hood.

Now that I have started looking , I see that most hoods have a 150 mm outlet.

My questions :

1) Would it be an absolute no-no to use an adaptor ?
2) If I did would this cause significantly more noise as this is something I severely dislike.

Thanks in advance

 

[jj4091]

Using an adator should be fine, especially as most , if not all, of the exit vents are only 100mm. I cannot see how it would increase the noise, kitchen extractor hood fans are very noisy anyway & I don't know a way of avoiding that.