What is aircraft air management system?

When traveling by plane, whether it is boarding or flying at an altitude of 10,000 meters, the appropriate temperature and fresh air in the cabin are the basis for a pleasant travel. And these are the important tasks of the air management system.

What is an air management system?

The Air Management System is an essential part of the Environmental Control System (ECS) that monitors cabin temperature to create a comfortable flight experience for passengers and crew. As a key air and temperature management system, ECS not only ensures air supply to the aircraft cabin, optimizing cabin pressure regulation and temperature control, but also detects smoke, suppresses fire and cools avionics.

How does aircraft air management system work?

1. Air conditioning

On an aircraft, the air supplied by the air circulation unit is processed by the air conditioning system. The air circulation components are located on the sides of the fuselage, close to the main landing gear, and manage air flow and air temperature. To provide air at the right temperature, the system achieves proper ventilation by mixing hot and cold air, controlling air flow and recirculating cabin air.

Air circulation components are an integral part of aircraft environmental control systems, responsible for functions such as air flow, temperature and pressure management. As the name suggests, the air circulation assembly consists of multiple equipment, including primary and secondary heat exchangers, air circulation machines, condensers, dehydrators, reheaters and other important components.

Going back to the air supply, have you ever wondered how the fresh air is fed into the air management system before being filtered and conditioned? Although the plane is in the air, it is not easy to achieve gas supply.

The air that reaches the cabin is called bleed air and is supplied to the air management system by the aircraft's pneumatic system. The bleed air is sent to the pneumatic system via the engine compressor or APU (auxiliary power unit) pneumatic line, and then directly into the primary heat exchanger of the air circulation assembly, and then injected into the passenger cabin, and so on.

The air distribution system inside the aircraft operates based on the ground air conditioning and intelligent recirculation system, sucking in, mixing the air, bringing it to the right temperature, and distributing it according to the aircraft cabin layout. This means that the cockpit and passenger cabin use different air sources. The air in the cockpit mainly comes from one of the air circulation components and the air mixing and distribution device, while the passenger cabin receives air directly from the latter.

Air supply is mainly done through ventilation ducts in the aircraft walls. A dual fan system controls air recirculation, directing air in and out of the cabin and mixing manifold, repeating the entire process. Air recirculation is important because it reduces the total amount of air required for air circulation components and can re-purpose up to 50% of cabin air for ventilation and auxiliary purposes.

Reuse of recirculated air inevitably leads to the question: Are air recirculation systems negatively impacted on health? The answer is no. Today, aircraft are equipped with high standard air filters, similar to those used in medical operating rooms. To ensure that air filters and air conditioning systems meet safety and hygiene standards, all aircraft in flight undergo frequent air quality checks.

2. Control the temperature

Another important function of the air management system is to control the air temperature. This is a key determinant of aircraft safety and comfort, and it is critical for aircraft and avionics manufacturers.

According to general standards, the cabin temperature should be maintained at 20 degrees Celsius. If the ambient air temperature is lower or higher than this benchmark, the crew will need to take action so as not to affect passenger comfort. Temperature control is extremely challenging.

Typically, the temperature control system activates an overheat switch in the air supply line. A switch alarm is triggered when the temperature exceeds the normal limit.

The cabin temperature control panel will then receive the temperature information, showing the current accurate air temperature. The temperature controller then compares the actual temperature signal from the sensor with the set comfort temperature. If the temperature is too low, the pneumatic system will supplement the air supply to the cooler areas of the aircraft, but in order to achieve a comfortable temperature, the supplemental gas needs to be mixed with the cold air first.

Pilots use air management systems to increase cabin temperature. In this system, hot air is drawn from the engine compressor, mixed in the manifold to achieve the proper ambient temperature, and sent into the passenger cabin.

Unlike in flight, air cooling is often required on the ground, which is still solved by compressed air.