According to Spider Robinson ("The Crazy Years"), the airlines got
> smoking banned aboard aircraft for a completely different reason: it
> meant they could slow down the air circulation systems in aircraft
> cabins by a factor of two or three (to save energy and money for the
> airline) without the fact being visible. The stagnant air that
> passengers now have to breathe as a result is almost certainly more
> of a health hazard than the slightly smoky air it replaces.
Probably not more so much as different. I really didn't like the smoke...
***** Moderator's Note *****
> Sorry, that doesn't make sense. Jet aircraft have so much spare
> power that air circulation is never a problem: the engines provide
> pressurized air for free,
It was almost free on older engine designs but I believe newer high bypass ratio fan engines take a non-trivial performance hit when you extract pressurized air.
so moving air through the cabin is very easy to do.
Regardless of the engine design the pressurized air is hot - too hot, I suspect, to drop to cabin temperature by passive cooling alone. That's more energy spent on active cooling.
In any case, it doesn't pass the common-sense test: why risk offending
> passengers when the aircraft has all the ventilation anyone could ever > want?
Why pressurize the cabin to only 8000ft? Why pack seats so close together? It's all a balancing act to keep costs down without driving off too many passengers.
Dan Lanciani ddl@danlan.*com