Fresh air is circulated to rooms of a highrise building during an emergency, such as a fire, from a source of compressed air located outside the building. Air is passed through insulated pipes to breathing units located in the rooms. Each breathing unit contains a plurality of extendable masks for placing...http://www.google.es/patents/US4467796?utm_source=gb-gplus-sharePatente US4467796 - Emergency breathing air supply system and apparatus
Emergency breathing air supply system and apparatus
