How does the pressurization system on a commercial aircraft work?

Question

you don't have to write an essay just explain it succinctly

Answer 1

Keeping it simple:

High pressure air is tapped from the compressor section of the engines.  The compressor is before any fuel is introduced, so this is pure clean air.  It is still very hot, though, just due to the heating as a result of compression.

This air is run through an air cycle machine, which is basically a mechanical air conditioner, to cool it and regulate the temperature of the cabin.  The conditioned air is then ducted into the cabin.

The pressurization is controlled by a regulator which opens and closes a valve called the outflow valve.  If the outflow valve is closed, the pressure in the cabin will increase.  If the valve is open, the pressure will decrease.  In all reality, the regulator continuously and automatically repositions the outflow valve to keep the cabin pressure at the selected value.

Answer 2

Any aircraft certified to operate above FL250 must have an approved pressurization system. The Aircraft is a sealed tube that hold its pressure. At FL370, the air is too thin for passengers where oxygen and pressure at a comfortable rate is produced, for example an 8 PSI defferential. So most time the cabin will be around 8000-10,000 feet cabin pressure altitude.

This pressurization is produced by bleed Air from the engines that cool and pressurize the air into the cabin. It is also moderated by an outflow valve at the rear of the aircraft outside. On the ground the outflow valvue must be fully open to relief the cabin of excess air so the doors can be open safely. If any of the systems should fail the consiquencies may be fatal. Where the pilots and passenger could suffercate slowly, or explosive or rapid decompression calls for an emergency Descent.

Answer 3

Have a look here it will answer your question.

www.boeing-727.com/Data/systems/infopr...

Aviator - maybe you need to check your altitudes for the requirements for pressurisation.

If pressurisation is not required below FL250 there must be a lot of very dead aircrew and pax floating around somewhere. Have you ever heard of Dalton's Law of Partial Pressure?

Normal pressurisation (using auto) will begin about 8,000 feet and keep cabin altitude at that altidude up to the aircraft's max ceiling.

Answer 4

Airliners used in commercial service always, always have a cabin altitude of 8,000' at the maximum certified ceiling of the airplane.

Answer 5

Like Andy said Airplanes no matter how high the plane altitude is always or mostly set at 8000 feet CABIN Altitude. This they have found out is comfortable and safe to both humans and aircraft structure. So if aircraft is at 39000ft and outside pressure there is around 5psi, cabin altitude is set at 8000feet and pressure inside is around 8psi.