ᐅ Exhaust hood / Roof or wall-mounted

Hello everyone,

We are still in the shell construction phase, but the question about the ventilation system for a desired island range hood has come up.

Should we vent the range hood through the roof or through an exterior wall?
What do you think? Opinions and experiences are welcome.

The most important question in general:
Is venting through the roof with a duct length of about 7 meters (23 feet) even feasible or practical?

A few more considerations:
Exterior wall:
Pros
- shorter duct length, about 2–3 meters (6.5–10 feet)
Cons
- dirt on the exterior wall from dripping grease!?
- west side, wind may blow the fumes back inside
- possible thermal bridge due to the wall penetration

Roof:
Pros
- weather conditions don’t matter
- external motor in the attic reduces noise
- no thermal bridge!?
Cons
- about 7 meters (23 feet) duct length
- high costs

Here are some key details that might be relevant:
- No controlled mechanical ventilation system
- Open kitchen to the living room
- Fireplace planned in the living room
- Chimney draws air from above
- We are not in favor of recirculating hoods