Where/how to put an inline extractor fan?

[Jeremy]

I've got a 120cm range fitting inside a fireplace / under the chimney in our kitchen. Range is all wired up and ready to go, but I need to sort out what to do about the chimney and extraction. My original plan was to run it up the chimney, but after reviewing a few forums it seems like the amount of air I'd have to move to use this as a pathway for extraction is nearly impossible. The other limitation that I'm working with is that my partner wants extraction as quiet as possible - she hates the noise of kitchen fans (fair enough).

 

So I'm looking at either running a recirculation / unvented fan in the chimney above the range (I've already got a low noise always-on Vent Axia Low Carbon Tempra going 24x7 in the kitchen) or, I guess I could run an inline ducted setup, which would have the benefit of being very quiet. But if I go with the latter, then what would I put in above the stove to install it? Just make a slimline box and paint it? Also 120cm range extractors are pretty expensive, so interested in creative options here as it seems like £1k is a lot to spend on an appliance that half the family will avoid turning on ever.

 

All ideas welcome!