The short explanation
An air fryer is a compact convection appliance. An electrical heating system warms the air, and a fan moves it around food. That circulating hot air promotes browning and crisping while cooking the food. It is not oil immersion, and it does not eliminate the need to check the food’s center. USDA’s air-fryer guidance describes the mechanism and still calls for a food thermometer.
The practical consequence is that air needs a route around and, where the appliance design requires it, beneath food. A crisper plate, mesh basket or perforated tray can form part of that route. Removing or covering it may change the cooking arrangement. Consult the exact manual before substituting an accessory or liner.
Why basket layout matters more than a quart number
Advertised quarts describe volume, while crisping a flat food also needs usable area and spacing. USDA warns that overfilling can obstruct circulation and cause uneven cooking or undercooking. Philips support similarly asks users to leave room around food or a baking dish in its listed models. A family-size volume can still require batches for a broad meal.
A dual-basket total is divided between its cooking spaces. Ninja’s US SL401 listing names two 5-quart baskets, so its ten-quart total should not be treated as an uninterrupted ten-quart base. The capacity planner can use your measured food footprint and documented basket measurements without claiming a universal portions-per-quart rule.
What controls do and do not tell you
Temperature and time settings describe the appliance program; they do not measure the internal temperature of the food. A preset is a stored starting setting. Philips notes that the model and the amount of food can require time adjustment. Fan speeds, heating positions and zone controls vary by exact product, and a larger watt rating alone does not prove faster cooking.
For food safety, measure the required minimum internal temperature with a thermometer and follow package directions. For a decision between models, compare documented controls, layout, operating space and support access rather than an assumed “crispness score.” We have not performed independent side-by-side cooking tests.
Test the idea with one familiar task
Pick a food and number of portions you cook repeatedly. Record the food footprint and how many batches the basket allows without crowding. Compare a one-basket model, separate zones and an oven-style tray if those layouts answer different needs. The finder and model profiles expose documented specifications; an unknown internal area stays unknown rather than being calculated from exterior dimensions.
Guide authored and sources checked 2026-09-15. No hands-on testing claimed.