The need to refocus depends a great deal on what you are cooking, the time of day, and the temperature you wish to maintain. A good rule of thumb is to plan to readjust every 30 minutes to maintain maximum heat. At noon the sun is high in the sky and moves quickly past the maximum focus point, creating the need to refocus more often. Later in the day you will not need to refocus as often. The Sun Oven is equipped with a built in Levelator, which keeps food level and avoids spills while being refocused. Many meals can be cooked without refocusing. Sun Oven users often will put their ovens outside, focused for the mid-day sun, with their dinner in it when they leave for work in the morning. As the sun moves overhead, the temperature in the Sun Oven chamber slowly rises to a cooking level. As the sun passes, the food is kept warm and when they return from work they have a warm, sun-cooked dinner. (Keep in mind food will not burn in a Sun Oven and that the chamber is extremely well insulated, allowing food to stay warm for hours.)