Chinese hotel offers 'filtered air', info on PM2.5 levels
Chinese luxury hotel 'Cordis' claims the air inside its premises passes through two levels of filtration and is continuously cleaned, while the double-glazed windows remain closed at all times. Further, information about the air quality and PM2.5 levels is displayed on TV screens in the guest rooms. The hotel also has a glass-sided swimming pool, a spa and twin ballrooms. 