I wouldn't count on that passive ventilation...! Ventilation for accommodation in the UK is extremely poorly regulated, or not at all, from what I can tell. I'

I wouldn't count on that passive ventilation...! Ventilation for accommodation in the UK is extremely poorly regulated, or not at all, from what I can tell. I've been given rooms with a hermetically sealed window and no A/C unit. I stayed at a brand new Hyatt the other day and the A/C had no "fan" only option (ie to avoid dry throats), and when off, provided no passive ventilation as far as I could tell. No opening window. And this was an aparthotel with a cooker etc. Absolutely ridiculous. Premier Inn's budget 'Hub' brand chain have sealed windows and just wall-mounted A/C (not fed fresh air from a central duct). Should be illegal I think legally they're allowed to use the 1 inch space under the door as ventilation... You actually need a lot of ventilation in hotels because they often use very harsh chemicals especially in the linen