How does the plane cool down?

A quick and effective method on the apron

Select the correct ground air-conditioned vehicle

Airbus does not recommend a certain type of air-conditioned vehicle, because each airline has its own operation mode, and the flight destination and time are different. With the change of cabin layout and number of passengers, there is no "correct air cooling equipment" for everyone.

Manufacturers of these devices have published cooling capacity in the United States in kilowatts or tons. However, this is indicative and does not necessarily ensure that the combination of temperature and flow when the aircraft is connected translates into good performance.

The air-conditioned car has a stable state higher than the ideal comfort zone. However, in sufficient time, it can effectively reduce the cabin temperature to below 27 ℃. Equipment that is stable in the comfort zone may be more powerful and expensive than what is really needed.

Quick fix on aircraft

AMM tasks related to air conditioning used to require the cabin fan to be turned on, which is a default position. This is related to a warning (CAUTION) on the grounds that avionics may be damaged. However, some airlines do practice "fan off" on their aircraft because they experience better air conditioning effect in the cabin. After analyzing the impact on avionics, Airbus' proposal on "fan on" finally proved to be conservative, except for A330/A340 series.

Except for A330/A340 series, when air is supplied on aircraft above+2 ° C, all Airbus aircraft are allowed to operate with "cabin fan off". This allows the maximum flow into the aircraft to be increased.

The maximum flow is increased from 1.0Kg/S - the upper limit when the cabin fan is on to 1.3Kg/S - the upper limit when the cabin fan is off. This increased flow can help achieve faster cooling, even if not combined with the best practices described here.

For the A380, to decide whether the cabin fan can be turned off, the operator should refer to the special AMM job card. Some ventilation systems (low pressure fan system) provide the air required by the rear electronic cabin. Therefore, if the cabin fan is turned off, it is necessary to check whether the exhaust works normally.

In addition, all Airbus aircraft should use fans during sub freezing operation: this is to prevent the risk of icing in the air conditioning mixing cabin.

Environmental laws and regulations, coupled with the determination of airlines and airports to be more "environmentally friendly", mean that efforts to find alternatives to APU on the ground are bound to continue and strengthen.

However, a simple established fact that applies to all air conditioning schemes is still of concern. All solutions depend on the careful implementation of all basic programs. Without these programs, they will become ineffective. Poor hose quality or careless use will destroy the advantages of any system.

The same degree of caution is essential when choosing the right option for a particular aircraft in a particular situation. The choice of air conditioning technology has a great impact on energy consumption and effective cooling.

In the near future, the automation trend of ground operation will make the air conditioning operation procedures more efficient. We will see that the temperature optimization time for aircraft preparation is shortened, the enhanced safety of automatic shutdown equipment in case of overpressure, excessive flow or low temperature, and simpler control equipment. This automation will rely on the electronic connection between the air conditioning equipment and the aircraft, and the temperature control loop between the aircraft and the crew will form a closed loop, so as to obtain the best performance for the equipment that can achieve and maintain the cabin temperature comfort target.