Indoor environments and human comfort, health and productivity
Indoor environment and learning in schools
Ventilation, damp buildings and health
Personalized ventilation systems
Dampness in buildings and health
Particles in indoor air
Human response to low indoor air humidities
Effects of air quality on airliner cabin occupants
An airplane cabin provides a unique environment compared to the conditions that most people encounter in their daily lives. The density of occupation is much higher than in any but the most crowded bars and theatres. The relative humidity level in the aircraft cabin is generally lower than is encountered in buildings in any but the coldest parts of the world in winter. In the cabin environment, as in any environment, thermal conditions as well as air pollutants and humidity levels affect the perceived air quality.
The studies of the effects of air quality on airliner cabin occupants were carried out at the Centre in cooperation with the Boeing Company as a number of experiments in a simulated aircraft cabin section with three rows of 7 seats that was constructed for the purpose in a climate chamber in the spring of 2003. Seats, carpet, wall-panels and a High Efficiency Particle Air (HEPA) filter, which had all been used in revenue flights for their normal service life, were incorporated in the simulated cabin and its environmental control system as realistic sources of cabin air pollution.
The make-up air from outside the building was dried using two dehumidifier units in tandem to ensure that the moisture content was as low as it is at altitude. A second flow of outside air was circulated around the simulated cabin at a temperature that was sufficiently low to maintain the inside wall surface temperatures at realistic values at each set temperature, so that subjects sitting near them would lose heat to the walls at the same rate as at altitude.
Exhaust air from the cabin was used to ventilate an en suite lobby, airlock and toilet facilities, creating a closed habitat.
Cross section of the Boeing 767 aircraft cabin prototype
Interior view of the aircraft cabin section erected inside Chamber 4
On average, 17 subjects were exposed in simulated 7-11 hour flights. In each experiment, four such groups making a total of 68 subjects were exposed to the conditions being studied. Two young women in each group served as flight attendants with an activity level of approx. 2.0 met, while the remainder of the group, acting as sedentary passengers engaged in normal in-flight activities (1.0 met), were evenly divided between young (aged 18-30) and elderly (aged 55-70), with equal numbers being male and female.
Subjects marked questionnaire scales to rate the air quality, thermal comfort and the intensity of a number of subjective symptoms commonly experienced during flight on entering, and 2 - 3 times during the flight. Objective medical tests of eye, nose and skin function were also performed.
The experiments have explored the effects of humidity, various purification technologies and thermal comfort on IAQ in the cabin.
Optimum balance between fresh air supply and humidity
Photo catalytic oxidation and gas-phase absorption air purification technology applied to aircraft cabins
Effects of air temperature on occupant evaluation of cabin air quality
Thermal comfort - Correlation between subjective assessments and thermal manikin measurements
Products of ozone-initiated chemistry in the aircraft environment