Neff was the first manufacturer to introduce fan, or convection, ovens at the end of the ‘70s as a solution to cooks wanting to batch-bake throughout the oven, and all the others followed suit. Circulating the air within the oven at high speed has two consequences: it improves cooking effectiveness by wrapping what is being cooked uniformly in hot air and at the same time delivers a consistent temperature throughout the oven space. There will always be some things which are better cooked without fan assistance and most fan ovens allow you to choose whether or not you use the fan. For example, you may want to start cooking with fan assistance at a high temperature, say when roasting beef, then switch off the fan and lower the temperature to finish.