1.10 - Enviornmental

Cabin Environmental System Overview

The environmental system of the airplane provides fresh air and heat to the cabin.
Because airplanes operate in such different temperatures based on where they are in the world, the pilot must be able to control the airflow and heat entering the cabin in order to ensure that everyone is comfortable.

In general aviation airplanes, there are usually two controls: a cabin heat control and a cabin air control.

In the winter months, when the outside air temperature is colder than desired, the pilot may turn on the cabin heat.
The cabin heat valve allows outside air to pass over the exhaust muffler shroud, which heats the air.
This heated air is then ducted into the cabin.

During the summer, the cabin can be cooled by venting outside air in.
By opening the cabin air control, outside air is scooped into the airplane and vented into the cabin through the same vents as the heater.
Additional vents may also be available that solely bring in cooler outside air.

To cool off, all you have to do is simply climb to a higher altitude where the air is cooler.

The system provides outside air for heating and cooling; the transcript describes heating via outside air passing over a muffler shroud and venting into the cabin.
The heater and cabin air control share the same vents for distributing air into the cabin.
There may be additional vents dedicated solely to bringing in cooler outside air.
Many GA aircraft lack air conditioning, so temperature management relies on heating, ventilation, and altitude changes.
Climbing to higher altitude is a straightforward method to reduce cabin temperature.