The five-star Crown Plaza hotel in The Hague, The Netherlands, lets the guest control the temperature and the speed of the ventilation. The air is supplied via Nova grilles. In total, seven Topvex air handling units have been installed to provide the whole hotel with cooled or heated air. The wellness centre has its own air handling unit, as does the restaurant. Fire dampers and roof fans have also been installed. The roof fans extract used air from the kitchen and the bathrooms.