A convection microwave is the combination of two kitchen appliances: a convection oven and a microwave. A convection oven is just like a conventional oven except that no heating elements are exposed and the heat generated inside the oven is recirculated by strong fans. This rapidly moving hot air cooks and bakes more evenly and, usually, more quickly than the still air inside conventional ovens. A microwave heats food using non-ionizing radiation. When molecules inside food absorb the energy from the microwaves, they start to bounce around. This internal friction makes the food heat up; the food generates its own heat, so no heat must be generated by the appliance.
Convection ovens can offer up to three modes: microwave cooking only, convection cooking only or a combination of the two. Sometimes this is called a "mix" feature.
The Microwave Part
The user can use the appliance as a microwave only. Want to reheat food or pop some popcorn? This is most effective mode for such tasks. When it comes to meats, casseroles and baked goods, users of convection microwaves often heat food using the microwave-only option first (because it is the fastest cooking mode) and finishing with the convection-only option (because this will produce more aesthetically pleasing food).
The Convection Oven Part
Cooking food with this mode means you can brown, broil, crisp and bake. To speed up cooking times, users use the microwave-only mode to heat through the food, then use the convection-only mode to crisp a pizza's crust or to brown a meat's skin. Like the microwave-only mode, the convection-only mode can cook an entire food item. It will just take a bit longer than using the microwave mode.
Convection microwave ovens that use the microwave mode and the convection oven mode together use the energy of a microwave and power of a convection oven. Food cooks faster, and users enjoy the browning/crisping that results.