How does air conditioning work on a commercial airliner? [duplicate]

Question

I know a lot about airplanes, but I've always wondered the vents deal with air pressure in the sky

Answer 1

Came across this diagram that sums it up pretty nicely:

• You get 'bleed' air from the engine compressor stage. On 'bleedless' aircraft, such as the B787, this is done by electric compressors instead.

• Air temperature and pressure is adjusted as necessary in the conditioning packs since it heated up a lot when it was compressed.

• Air is then distributed to the different 'zones'. A bit of the cabin air is recirculated.

• Some areas, such as the cockpit, generally receive air directly from the packs without recirculating at a slightly higher pressure, to blow possible smoke away from the interior and to prevent smoke being recirculated into the cockpit. For the same reason, you try create a flow out through the baggage hold.

Here is a more complicated diagram from avsoft's website for a CRJ200: