It'll be well sealed. The only thing is that I've never really used
kitchen
extractors simply because every single one I've encountered has been a
"recirculating" type (read: completely f***ing useless).

So true. Crappy one in our house put in by previous owner. You might as
well flap a carbon filter in the air for all the good it does.

My mother has a properly vented one and it's great for removing steam, and
therefore humidity on high pressure occasions like Xmas dinner. It's really
powerful. If we get one like that, hubby says we'll have to tie bricks to
No 2 daughter's ankles as she might get sucked out. Poor wee
skinny-ma-link.