What is the difference between convection and radiation? When it comes to hot air balloons, it’s important to know that they conduct convection, not radiation.
This simple knowledge can prevent dangerous situations for those onboard a balloon.
An object is said to radiate heat when it emits thermal energy in the form of infrared waves.
Objects that produce radiant heat are generally at a higher temperature than those they’re heating up, but not always. For instance, the sun radiates more heat on Earth because it’s closer and hotter than our planet.
A hot air balloon is a lighter-than-air craft that uses an enclosed gas balloon, propane, butane, or heated air as its lifting gas. The balloon’s buoyancy is produced by heating the lifting gas.
What is Conduction?
Conduction is when one object transfers heat to another without direct contact. This can be through solids (like metal) or liquids and gases (like water).
The transfer of heat from a region where it is higher in concentration to one that has less will continue until an equilibrium temperature is reached between them both.
In this case, warm air inside a balloon rises because there’s more density than at its surface level due to cooler outside temperatures meaning as soon as it reaches the top of the balloon, it cools down and starts going back down again causing convection currents which help keep things moving vertically instead of horizontally as radiation would do.
With conduction, warm air rises automatically due to buoyancy and it is this process of rising which makes the air balloon rise.
What is Convection?
Convection is the transfer of heat through a given fluid. Convective currents take place when there is an uneven distribution of temperature or pressure in the atmosphere, whether it be on land or sea surface.
Convection has a lot of variables but it can be defined as the transfer of heat through currents in fluids (liquids and gases) due to thermal energy or temperature differentials.
The type of convection we are familiar with is where hot air balloons rise into colder air, causing them to lose both their buoyancy and heat because they’re taking up less space–this is called “natural” convection.
If you float an object on water heated below 100 degrees Celsius, then the solute particles will move faster than those at room temperature which leads to surface tension changes resulting in what’s known as laminar flow or bounded fluid motion while turbulent flow is characterized by turbulent motion.
Now, when you increase the temperature of that water to over 100 degrees Celsius and it becomes a gas, then convection currents are generated.
It’s worth pointing out here that this type of heat transfer can be described as either conduction or radiation depending on how the energy is transferred–heat from an object/gas to another object/gaseous material through direct contact (conduction) or electromagnetic waves in space without any form of contact between objects involved (radiation).
What is Radiation?
Radiation is the process by which energy is emitted in a form not directly detectable by our senses. This means that as long as we have enough atmosphere for gases to diffuse into, then all objects from the sun to a hot air balloon are constantly emitting heat due to radiation!
The temperature at which thermal energy is emitted by an object is also dependent on two factors: how much material there is (a large mass emits more radiation than does a small volume) and what color that object is (which determines its ability to absorb radiant energy).
A black sheet placed between hot coils could be heated even if they were not producing any measurable amount of infrared radiation.
A hot air balloon is a large object that emits thermal energy due to radiation as well. However, the heat from a hot air balloon is not directly detectable by our senses because it is happening in the infrared range of the electromagnetic spectrum where we can’t see or feel any temperature change.
This means that as long as we have enough atmosphere for gases to diffuse into then all objects from the sun to a hot air balloon are constantly emitting heat due to radiation!
What type of heat transfer is a hot air balloon?
The hot air balloons are examples of convection, not radiation because the heat is transferred by a fluid, which is closer to a gas than liquid and it’s going up from one layer in order to transfer the heat to another layer or compartment where there will be more collisions with other particles that have less kinetic energy.
This type of transfer can happen when hotter layers rise while cooler ones sink due to gravity as well as atmospheric pressure variations associated with changes in weather fronts around Earth.
Radiation would occur if you were heating something on earth using microwaves because this form of electromagnetic waves like light emitters has a lot less friction–so they travel faster through space but slower through the atmosphere.
So, this is what we have to say about convection and radiation: Convection occurs when not only heat is transferred by a fluid but also the particles that are in it (whether they be liquid or gas).
A balloon is filled with compressed gas which becomes hot during expansion – this then heats up its surrounding environment causing warm air to rise from beneath the balloon while cool air falls downward from above, spreading out evenly over time so that no one area has too much weight for too long.
The heated air is then dissipated outward and rises to the top of the balloon, where it cools off as it comes into contact with other layers of colder ambient atmospheric air
As a result, this creates convection currents like those which exist in an ordinary pot on your stovetop or when you boil water for tea.
This process is similar to how heat can be transferred through conduction from one object to another; though instead of heating up metal objects such as pots and pans that are touching each other via their atomic bonds, hot gas molecules are transferring heat energy by colliding against themselves at different speeds than cooler ones do.