Cooker hood installation

1st question, gas-(Dual Fuel) or electric range. This makes a difference to the height the cooker hood has to be at above the hob For gas hobs, clearance above needs to be somewhere between 650 and 750mm depending on the manufacturers instructions. In a scenario like this, I assume you cannot core drill through the wall behind the hood because it's a partition wall into another room ? Otherwise that would be the best way to route the venting kit. The only other option you have is to run it sideways to the nearest outside wall. In most kitchens where this is done the venting kit sits on the top of the kitchen cupboards and is hidden by the mouldings at the top of the cupboards with additional woodwork surrounding the cooker hood chimney. If this is not possible then the only other option is to run the vent along the edge where the ceiling and walls connect and box that in. Maximum allowed run for most cooker hood vents is 3m. Anything above that will cause exhaust issues and put too much strain on the hood motor potentially causing it to overheat and burn out. The other option of course is to internally vent. This would mean buying charcoal filters every few months, which you will eventually stop doing if you ever buy any at all. The charcoal filters are supposed to filter out the smells. However they don't do a fantastic job. (Venting to outside air is always the best install method) The wire mesh filters that need cleaning regularly collect the grease. These are the more important filters and as far as I know are no more or less efficient whether you internally cycle the air or vent to outside. One more piece of advice. If you need to query something like this in the future, it helps a lot to add a photo of the task. Hope that helps ?