HVAC Cleaning Chemicals

Air Conditioning System
PACK
Components
Air supply
Operation of PACK
Air distribution
Recirculation
Temperature Control
Air Conditioning System in modern aircraft
The air conditioning system is supplied by air processed through two packs that regulate airflow and temperature as required. Airplane air conditioning system mix hot and cold air to achieve the desired temperature.

Aircraft types vary, but the principles and operations of the air conditioning system are the same in all aircraft. The primary parts of the air conditioning system have these functions:

Control fresh air flow for airplane pressurization and ventilation
Control the flight compartment and passenger cabin temperature
Recirculate cabin air for ventilation
Air Conditioning Pack
The pack allows bleed air to be cooled for conditioning the flight and passenger compartment. The air conditioning system is based on an Air Cycle Machine (ACM) cooling device, which is mostly used in turbine-powered aircraft. The air cycle system is often called the air conditioning package or Pack.

Usually, Air conditioning packs are located left and right wing to body area near the main landing gear of an airplane. Packs remove the excessive heat from bleed air entering to packs from the aircraft bleed air system and supplies air to the cabin at the desired temperature visit FlyBy Aviation Academy.

Air Conditioning Components

Major components of the air conditioning pack are:-

Pack valve – Flow control and shutoff valve (FCSOV) controls the flow of bleed air into the pack.
Primary Heat Exchanger – Cools the engine/APU bleed air.
Secondary Heat Exchanger – Removes the heat of compression of the ACM.
Air Cycle Machine (ACM) – An ACM comprising a compressor and a turbine mounted on the same shaft.
Condenser – Condenser uses refrigerated turbine discharge air to cool incoming bleed air to a temperature low enough (below the dew point) for moisture condensation to occur.
Re-heater – The reheater is used to raise the temperature of the air before it reaches the turbine inlet to vaporize any remaining water droplets for turbine protection.
Water Extractor – The water extractor removes the water from the moisture produced by the condenser.
Water Spray Nozzle – It is located at the secondary heat exchanger inlet and sprays on it water drained from the water extractor in order to increase the cooling capacity of the heat exchanger.
Air supply for Pack operation
The air cycle air conditioning system is supplied with air by the aircraft pneumatic system. In turn, the pneumatic system is supplied by bleed air tap-offs on each engine compressor section or from the APU pneumatic supply. Bleed air from the pneumatic manifold is directed into a primary heat exchanger of Packs.

Operation of Air Conditioning Pack
When bleed air goes through the primary heat exchanger, ram air removes some of the heat. This partially cool bleed air goes to the compressor section of the air cycle machine. The compressor section increases the pressure and temperature of the partially cool bleed air. This compressed-air goes to the secondary heat exchanger.

Air from the ACM compressor outlet flows through the secondary heat exchanger. A cross-flow of ram air removes heat before the air enters the ACM turbine inlet.

Air conditioning is provided in aircraft for the comfort of passengers. The same conditioned air is also used for cabin pressurization in the airplane.