That kitchen extractor hood [part 2]

[kia cat]

Trying to save lobbing out too much cash on the vent kit, by reducing the size of the vent diameter . ie step it down from 6 inches to something smaller [and cheaper]

Is there any way of calculating what the extraction rate of the machine is? Hygena who made it, are I think no longer in production, there's nothing on the machine's info label apart from serial no, model and voltage plus it's rated at 230 W maximum 260 W. I'm guessing that's the amount it consumes when it's running. Would this somehow give an indication as to how much air it'll shift?

For our kitchen we'd need a rate of 168 m³/hour. Hope that makes some sense. Thanks

[AlBags]

You can't. The power consumption of the motor would have absolutely nothing to do with the air flow rate. Anyway, it would vary according to the obstacles, no of turns, etc, in the outlet.
That figure is quite easy to achieve, though.

[Prudie]

Hello Albags, are you just back from work?

[kia cat]

thanks AlBags, so is it feasible to scale the size of the trunking down?

[AlBags]

yep

I have never seen anyones domestic kitchen that would need a 6" duct.
Bigger=Bigger Fan=Lower Speed=Lower Noise though!