Quote:
Originally Posted by Elsi
To save money, the air within the plane is not turned over very quickly, resulting in a higher carbon dioxide level.
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Quote:
Originally Posted by pilotbob
I'm sorry what? I never heard of this. How do you think that will save money?
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Quote:
Originally Posted by Sparrow
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I just repeat what I have heard.
If you'll search Google with "airplane air quality", you'll find a lot of information about the fact that commercial airliners recycle the air as opposed to bringing in fresh air -- and the reason given is cost/fuel savings.
I found this on the Boeing site:
Quote:
Pressurized air for the cabin comes from the compressor stages in the aircraft's jet engines. Moving through the compressor, the outside air gets very hot as it becomes pressurized. The portion drawn off for the passenger cabin is first cooled by heat exchangers in the engine struts and then, after flowing through ducting in the wing, is further cooled by the main air conditioning units.
The cooled air then flows to a chamber where it is mixed with an approximately equal amount of highly filtered air from the passenger cabin. The combined outside and filtered air is ducted to the cabin and distributed through overhead outlets.
Every unit of pressurized air extracted from the engine core has the effect of reducing fan thrust by an even greater amount, and that degrades fuel efficiency more severely on this type of engine than on the older type. By providing the cabin with a mixture of about 50 percent outside air taken from the compressor and 50 percent recirculated air, a balance has been achieved that maintains a high level of cabin air quality, good fuel efficiency and less impact to our environment.
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There are some experts who contend that the percentage of fresh, outside air is less than the 50% quoted in this document. And, it costs money/fuel to cool the compressed outside air.