SYSTEM FOR IMPROVING THE WELL-BEING OF HUMANS IN A COMMERICAL AIRCRAFT

A system (10) for controlling the quality of the cabin air in an aircraft of the type having a cabin air recirculating system (37, 43) which introduces selectable amounts of fresh outside air, an arrangement (25, 27) for venting controllable quantities of cabin air to the atmosphere, and a source of oxygen-rich air (49). The system (10) includes sensors for monitoring the partial pressure of carbon dioxide (15) in the cabin air, the partial pressure of oxygen (17) in the cabin air, the humidity (19) of the cabin air, and the total air pressure (21) of the cabin air, and an air quality controller (23). The air quality controller (23) includes at least four inputs, one input connected to each of the sensors, and at least two outputs, one output connected in controlling relationship to the source (49) of oxygen-rich air and another (47) connected in controlling relationship to the cabin air recirculating system. The air quality controller (23) determines a passenger discomfort level by combining the four inputs and upon detecting a specified value for the passenger discomfort level, actuates at least one output to enable either the source (49) of oxygen rich air to increase the partial pressure of oxygen in the cabin air, or the recirculating system (43, 37) to increase the introduction of fresh outside air thereby reducing the partial pressure of carbon dioxide in the cabin air. The system (10) may optionally also increase the cabin air humidity when the monitored humidity falls below a predetermined minimum. The air quality controller (23) also responds to the monitored total air pressure of the cabin air to modify the quantity of air vented to the atmosphere to maintain the total cabin air pressure within prescribed limits.