The diagram illustrates the components of a hot air balloon and explains its operation.
Overall, the balloon comprises three main parts: the envelope, the burner, and the basket. The temperature of the air inside the envelope plays a crucial role in determining whether the balloon ascends or descends.
The envelope, shaped like an inverted teardrop, features a parachute valve at the top, which functions as a self-sealing flap that controls the release of hot air. The envelope’s structure is supported by gores and panels, which provide shape and stability.
Attached to the lower part of the envelope is the skirt, which connects to the burner via ropes. The burner, located above the basket, is fueled by propane stored in cylinders within the basket. When propane is mixed with air, it produces a flame that heats the air inside the envelope. As hot air is lighter than the surrounding cooler air, the heated balloon rises. Conversely, to initiate a descent, hot air is allowed to escape through the parachute valve, lowering the internal temperature and causing the balloon to descend.