How does a hot air balloon float?

Learn why a hot air balloon floats and a simple explanation of the science behind lighter than air technology. read more

Hot Air Balloon envelopes can withstand temperatures up to approximately 250°F for long periods of time. Hot air balloon burners use liquid propane tanks (just like your grill) that travel through tubes to the burner to heat the envelope of the balloon. read more

Helium is seven times less dense than air. A birthday balloon and helium together weigh less than an equal volume of air, so the balloon rises. If you add weight to it, the balloon sinks. If you add only enough to balance the force of buoyancy, the balloon will float in mid-air. read more

1) A hot air balloon stays on the ground (or descends) when the air inside it is too cool. In this case, the weight of the balloon (blue arrow) is greater than the lift (red arrow). 2) When the air inside is a bit hotter, the balloon floats at a steady height because the lift force and weight are now the same. read more