The major difference between a microwave oven and a convection oven are the method by which they heat food. Each has its pros and cons.
How Microwave Ovens Work
Microwave ovens heat with microwave radiation. Rather than the heating elements present in a conventional or convection oven, microwave ovens contain a magnetron, which is a device that converts the energy supplied from an electrical outlet to microwave radiation. The radiation then passes through a waveguide that controls the direction of the microwaves and sends them into the cooking chamber. The microwaves that bounce off the cooking chamber are absorbed by the food item contained inside. The microwaves excite the water molecules present in the food causing friction and heat, which in turn begin to cook the food.
Pros of Microwave Ovens
Speed. The obvious benefit to this appliance is its speed in heating up foods. A food item that may take a minute or two to heat up in a microwave may take in excess of fifteen minutes in a convection oven. For those looking for instant gratification, the microwave is the way to go.
Energy Efficient. Microwave ovens use 50-65% less energy than a conventional or convection oven. This also means that they cost less to run. You can also cook small portions of food without having to heat up the whole oven.
Don’t Emit Heat. Unlike a convection oven, microwave ovens stay cool when they cook so they are ideal for use in the summer to keep your home cool.
Additional Options: Many microwave ovens come with additional options beyond cooking food. For example microwave popcorn is convenient and specifically manufactured for use in the microwave. Many units also have the ability to defrost a frozen item prior to cooking.
Cons of Microwave Ovens
Food Quality. The standing waves of a microwave often have hotspots that heat up one area of the food very quickly while another area is still cold. The addition of a turntable does help to move the food through the hotspots at different points, but is not always 100% foolproof. This can also leave foods partially raw and unsafe for consumption. This appliance is also not up to par for baking and broiling as compared to a convection oven. Most microwaves do not brown and crisp.
Often Used Incorrectly. Many instructions for cooking properly are often ignored that could be potentially harmful. As an example, many food items require that the finished product must be left to stand prior to consumption. This isn’t solely a suggestion warning that the food is hot. Food that is microwaved is still cooking when the power is off, and the instructions take this into consideration when informing how long to cook it.
Safety Concerns. When improper containers are used in the appliance, safety concerns arise from leaching chemicals into the food. For example, it is not safe to defrost meat in its original packaging that includes a Styrofoam tray. It is also unsafe to use plastic containers that are not labeled microwave safe by the FDA for the same reasons.
How a Convection Oven Works
How They Work: A convection oven is better compared to a conventional oven. A convection oven uses the same radiant heat as a conventional oven that has a heating element at the top and bottom, but the convection oven has an additional heating element in the center with a fan that evenly distributes the heat throughout the oven. The benefits of this oven over a conventional oven are many. It cooks food up to 25% faster and it cooks food more evenly.
Pros of Convection Ovens
Food Quality: The convection oven evenly cooks food for better food quality as well as better safety in ensuring that all parts of the food are cooked safely. The convection oven cooks food more evenly than a microwave oven. It can consistently handle all cooking jobs such as baking and broiling.
Large Portions: Convection ovens can accommodate large portions and can usually handle more than one food item. For instance, you can cook a turkey dinner in the oven, which would be an interesting feat in the microwave.
Cons of Convection Ovens
Speed: Even though a convection oven cooks faster than a conventional oven, the microwave still wins when it comes to heating food faster.
Cost More to Run: Because it takes longer to cook foods in a convection oven rather than a microwave, the cost to run it is substantially higher.
Emit Heat: Running a convection oven for any length of time heats up a room, which can become uncomfortable in the summer. If you are using air conditioning, this increases cooling costs. However, this could turn into a pro in the winter months.
When Two Become One
The convection microwave is typically what you find today in the appliance aisle at Best Buy. It’s the best of both worlds and allows for all types of cooking. The modes that you can select on microwaves determine how to arrange heat molecules around your food and the temperature of what those molecules should be. In all of these microwave ovens, you need a cooking chamber, fan and a heating element. Foods heat up quickly with these types of ovens and considerably faster than any other type of oven available, which is why they’re so beneficial for many households today.
Journal of Physics Education; Michael Vollmer
Physics of the Microwave Oven
California Energy Commission-Consumer Energy Center
US Department of Agriculture- Food Safety and Inspection Service
Cooking Safely in the Microwave