Bacon produces a lot of grease and leaves a mess of tiny burnt bits and crumbs. While this may be easy to clean using other cooking methods, it's not so easy in an air fryer.
Grease can be easily drained, saved, or disposed of while frying, but cooking bacon inside a small, enclosed space without proper drainage means it will begin to build up.
The movement of hot air smears the fat all over the basket, so cleaning the grease and burnt ends out of your air fryer basket afterward is important so it doesn't burn and smoke.
Overfilling the basket will result in uneven cooking and excess grease. Only use enough bacon to form a single layer, and cook it in batches, cleaning the basket after each one.
The trick to safely cooking bacon in an air fryer relies on the temperature. The smoke point of bacon is around 400 degrees, so cooking at a lower temperature should prevent smoke.
A good starting point to cook your bacon is 350 degrees, but you can increase or decrease the temperature as long as it doesn't exceed the smoke point.