if the temp.of the altitude where the airplane is below 0 then what is the use of an A.C and how pas. survive?

Answer 1

The principle of pressurization in a aircraft is that compressed air is pushed into the aircraft, and a controlled valve opens and closes to keep the cabin at a set altitude.The compressed air needs be varied in temperature because the aircraft has to be able to operates from a hot airport say 40 Celsius to its cruising temperature of say -50 Celsius and all the time the cabin needs to at 22 ish Celsius.While the aircraft has to operate from sea level to 40000 feet the cabin should stay between sea level and 7000 feet approx say the passengers can remain comfortable.

Answer 2

Human beings are used to atmospheric pressures and ambient temperatures. Every airplane has a system for cabin pressurization and temperature control. We can not imagine staying alive at temperatures and pressures encountered at 35000ft which is the normal altitude for commercial carriers where they get maximum fuel economy. At the altitude there is very rare atmosphere and temp.are of the order of -20
to -30degC. If per chance the cabin pressurizing fails there will be instant death of passengers due to veins bursting due to low pressures outside,lack of oxygen and freezing temperatures.

Answer 3

If the temperature outside your house is 0 degrees, how do you keep warm in your house?
Modern jet aircraft are equipped with cabin air systems that control pressurization, airflow, air filtration, and temperature. Commercial jet aircraft fly at extremely high altitudes, and therefore, their cabin air systems must provide a safe environment.

Answer 4

It's not really an AC itself air recirculation in the cabin