There are so many different terms nowadays regarding kitchen appliances. There are air fryers, convection ovens, toaster ovens, conduction stoves and so on. Many of these terms are based on simple physics and it will help you to understand how actually these appliances work on the simplest levels. So how does an air fryer transmit the heat to your food? Does an air fryer use convection energy? Let’s find out.
Does an air fryer use convection?
Yes an air fryer uses convection energy but not in the natural form. The heating element heats up the air and this air heats up the food, and therefore we can say that air fryers use convection. On the other hand air fryers speed up the process with their ventilation element that helps the circulation of the hot air. So basically it doesn’t use the convection currents (natural movement of hot air) but it does use convection energy. This ventilation unit comes very handy because it can reduce the amount of time needed for cooking dramatically which makes air fryers very useful. Basically this is why you can preheat your air fryer in a matter of minutes.
Difference between convection, conduction, and radiation
A very handy article describes conduction as when heat transfers via direct molecular collision. An area of greater kinetic energy will transfer thermal energy to an area with lower kinetic energy. This means heat is directly transferred from one hotter object to cooler one. A hotter object have particles that have greater kinetic energy, which means its particles travel faster. When these particles collide with an object whose particles travel slower (which means it’s a cooler object), then it will speed up the particles of said object. This will make the cooler object heat up.
Some examples of conduction:
- When you put your pan on the stove the gas flame directly passes the thermal energy to the pan
- When you put the hamburgers on the grill grate the flame passes the heat to the hamburger and the grill grate and then the grill grate to the hamburgers
- On a hot summer day the surface (like pavement) passes the thermal energy to the air
- When you place your hand on the window at it becomes warmer
Now that we have covered thermal energy directly transferred (aka conduction) we can talk about convection. The easiest to understand convection is that a fluid or gas (like water or air) likes to travel when it is heated up. And it travels upwards. And also it carries the thermal energy with it. Basically that’s what conduction is.
Some examples of convection:
- A space heater (radiator) that heats up the air surrounding. The air travels up which pushes cold air down that gets heated too
- Boiling water: The water on the bottom travels and pushes down the cold water down
- The pavement heated up on a summer day makes the air travel upwards where it can cool down
- And of course an air fryer use convection also
Thermal radiation occurs when the emission of electromagnetic waves heats up a surface. The waves will carry the heat away from the emitting object. It is a bit harder to understand but let’s just say that some particles (like protons, electrons) get charged and these charged particles then emit the waves which result in a heat. The most well-known form of radiational energy is the sun. The heatwaves travel through the solar system in vacuum (where no gas, liquid or solid matter exist) and when it reaches earth it will heat up the surface. It is also important to note that all materials radiate energy. The hotter the object the more thermal energy it will radiate.
Difference between a convection oven and an air fryer
There are some differences between a convection oven and an air fryer but in terms how they work they are very similar. They both use hot air to fry your food and a ventilation element to speed up the process. As we learned from our previous section they both use convection thermal energy to get the job done.
So the answer is yes, an air fryer use convection energy, but with the help from its ventilation element. In terms of mechanics they are very similar to convection ovens. Therefore food prepared in air fryers can be cooked so evenly because the heated air creates an even temperature in the heating basket.
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