"In an air fryer, heat is generated by coils right above the double-walled food chamber. A fan on top of that pulls the air up and forces it to travel down and along the outer shell of the chamber. There is an opening at the bottom of the chamber that is exposed to the food, so the super heated air is forced up and is dispersed in the chamber by the food. That air is then pulled up by the fan and circulated around the chamber again. To avoid over crisping and drying out the food, the air fryer has an exhaust that contro ls the pressure inside the chamber. "
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