How does a hot air balloon fly?

Have you ever wondered how a hot air balloon flies? Or why are hot air balloons so big? Or how do the balloons keep the air inside if they have a hole at the bottom? Well, now is the time to get the answers to these questions! Have you ever wanted to fly like a bird and soar high in the sky?

Do you think it would be fun to soar high and see everything from above? Even if it is very unlikely that we will grow wings and be able to fly on our own, we can still have the chance to see things from a bird's perspective, simply by climbing into a hot air balloon! You've probably seen hot air balloons painting the sky like colorful dots in bright colors and funny patterns.

But... have you ever wondered how these balloons stay in the air? Hot air balloons fly due to a very simple scientific principle: warm air rises: warm air is lighter (and less dense) than cold air, which means it rises.

If you live in a house with several floors, you have probably already felt the effect of this principle on your own skin, especially on hot summer days. If the basement of your house will generally be quite cold, and the ground floor quite comfortable, upstairs you will notice that the air is much warmer, and when you go up to the attic you will find the hottest air in the whole house.

The actual balloon part of a hot air balloon is called the "tire" and is generally made of nylon. Nylon is the ideal material for hot air balloons, because it is light, resistant and does not melt as quickly as other materials when it comes into contact with heat. A burner is positioned under the balloon, which uses propane as fuel to send the balloon up and make it move.

When the pilot lights the burner, the flame heats the air and directs it to the tire. When the air in the tire heats up, the balloon begins to inflate and rise, pulling the attached basket along with it - and everyone inside it. 0.030 cubic meters of warm air inside a tire can lift 7 grams, which is a very small weight. That's why hot air balloons must be massive.

In order to lift the weight of a basket and its passengers, they must capture a very large amount of hot air. You are probably wondering why there is a hole at the bottom of the tire... Shouldn't it be closed? Why doesn't the air come out of it? Warm air floats, which means it rises and therefore will never fall to the bottom of the balloon.

As long as the air remains warm, it will rise, pushing the balloon up and keeping it afloat. The more air the balloon contains, the greater its buoyancy. Which means that bigger balloons can rise more than small balloons. When it's time to return to the ground, the pilot opens a valve called the "parachute valve".

The valve is basically a fan located at the top of the tire, which allows part of the warm air to escape from the tire. The partial exit of the warm air also determines the gradual cooling of the remaining air, so that the balloon will begin to descend slowly towards the Earth.

I guarantee that a hot air balloon flight is an experience you should not miss!