Vertical ducting for a hood

[Jemo]

Is there a problem with a straight vertcal duct above a cooker hood?

I'm converting an old kitchen with bathroom above so very limited options for routing the duct. Easiest solution is to chase the duct vertically through the bathroom above then out onto roof.
No bends = good flow, doesn't it?

Then I went to sleep and woke up thinking about all the possiblee problems ....

.... will grease run down and plop all over the hob?

Can extractors push a vertical column of air? It'll be about 5 metres in length.

 

[JohnD]

The vertical duct will have a big advantage - natural flow of warm air will give you a current upwards without you neededing a fan.

You may want some kind of control to stop it taking warm air away on a cold day when you're not cooking, though.

And a washable grease filter as it will get disgusting up there.