How is 600-degree air from the engines cooled for cabin comfort?

The process of cooling 600-degree air from the engines for cabin comfort involves utilizing bleed air and compressing it in the aircraft's environmental control system. In this system, bleed air is taken from the engine's compressor stage, where it is at a high temperature and pressure. This air is then cooled down through various processes before it is delivered to the cabin.

When this high-temperature air is compressed, the pressure increases, which allows a subsequent cooling phase where it can be mixed with ambient air or cooled down using heat exchangers. This results in the delivery of effectively conditioned air to the cabin, ensuring a comfortable environment for passengers and crew during flight.

The other options do not accurately describe how cabin air is cooled. For instance, passing through the combustion chamber would not be applicable as it would significantly increase the temperature rather than reduce it. Heat exchangers after the turbine do play a role but are not the primary method in this context. Adding cold air from outside can happen, but it is typically not the main method for cabin air conditioning, especially at high altitudes where temperatures outside can be extremely low. Thus, the approach of using bleed air through compression is central to the cabin cooling process.