Modification of a 747 Aircraft Ventilation System to Reduce Tobacco Smoke Transport

Abstract

The cabins of most aircrafts contain smoking and non-smoking sections in the same compartment. In addition, two “Common Smoking Seats” located in the left rear of the cabin are provided for people located in non-smoking sections who wish to smoke during a flight. Because the smoking and non-smoking sections are in close proximity, and because current ventilation systems are not properly designed to prevent smoke migration away from smoking seats, the environment around the Common Smoking Seats becomes filled with smoke. We have developed a new ventilation system for improving the environment around these seats. This new ventilation system was developed after measurements and numerical simulations of the airflow patterns and velocity distribution in the economy cabin of a 747 aircraft. This was a joint project between Japan Tobacco Inc. (JTI) and Japan Airlines (JAL). The new system uses two smoking seats situated back-to-back with the seats located the furthest back in the stern of the aircraft. The new ventilation system uses a special grill on part of the air-conditioner outlet to control the ventilation airflow direction. Numerical simulations indicated that one smoking seat should be located in the left rear and the other in the right rear of the aircraft. Numerical simulations were also used to determine the optimum airflow direction. After installing this ventilation system into a Boeing 747 aircraft of Japan Airlines for international flights, the average smoke concentration in the environment around these “Common Smoking Seats” was reduced by a factor of about 3.