Aircraft Air Conditioning Pack

Apu or engine 5 th and if necessary 9 th stage bleed air hot is pre cooled by fan air before entering the pack.

Aircraft air conditioning pack. Each acm and its components are often referred as an air conditioning pack the air cycle cooling process uses air instead of a phase changing material such as freon in the gas cycle. An air cycle machine acm is the refrigeration unit of the environmental control system ecs used in pressurized gas turbine powered aircraft normally an aircraft has two or three of these acm. The air conditioning system is based on an air cycle machine acm cooling device which is mostly used in turbine powered aircraft. However ram air can only be used at a level below 10 000ft.

Air cycle air conditioning is used on most turbine powered aircraft. Cabin temperature control system the temperature and quantity of the air must be controlled to maintain a comfortable cabin environment at all altitudes and on the ground. On other aircraft douglas aircraft dc 9 series the a c packs are located in the tail. Depending on the airport facilities this is either a preconditioned air system supplied by the airport or a mobile generator unit is used to pump air.

There are two types of air conditioning systems commonly used on aircraft. An ecam electronic centralized aircraft monitor constantly measures the following parameters of the conditioning system. Pack flow compressor outlet temperature by pass valve position and pack outlet temperature. Inside the pack bleed air is cooled by ram air through heat exchangers and an air cycle machine.

If the apu is not available a ground source of air can be used to supply the aircraft. In some designs they are installed in the wing to body fairing between the two wings beneath the fuselage. A water separator collects water condensed by the cooling process to avoid icing. Usually air conditioning packs are located left and right wing to body area near the main landing gear of an airplane.

On aircraft which use bleed air for the air conditioning it also provides a flow of air to feed the packs. Pressurization is achieved via the air pressurization system.