Oven insulation is used to keep the high heat of an oven inside of the appliance and out of the surrounding room. Manufactured from a fiberglass material similar to the insulating bats inside of the building's walls, the insulation for ovens is different with a much higher heat rating than traditional home insulation materials. The average household insulation would melt after continuous exposure to the heating temperatures of the common oven. The purpose for the insulation in the oven is two-fold: first, the insulation allows the oven's temperature to surround the oven evenly and eliminate any cool spots. Second, the insulation prevents the top of the oven's exterior shell from becoming too hot to touch and burning a cook's hands and arms.
The oven insulation in a typical oven is sandwiched between the actual oven compartment and the metal shell of the appliance. While it is encased between the two elements, the insulation can become grease-covered over time, reducing the efficiency of the material to perform as intended. This can also create a condition that causes the oven insulation to begin breaking down and disintegrating. Often, this disintegration can happen over time and some antique and vintage ovens may require replacement insulation to be installed prior to using the appliance in a modern kitchen.
In some industrial ovens used for curing powder coating and paint, and for ovens used for baking objects such as engine blocks and other automotive parts, the temperatures are commonly higher than anything used in the kitchen oven. These ovens typically require denser layers or even multiple layers of oven insulation to prevent the heat from radiating out and away from the oven. The ovens also depend on the insulation to retain the interior heat evenly as well as to make the ovens more cost effective when in use. These high-temperature ovens will often have a replacement schedule for changing the insulation before it completely breaks down.
In the typical installation process, the oven insulation is not glued into position inside of the oven's walls. The adhesive would become hard and brittle after a few heating cycles and could actually damage the insulation material. The insulation is commonly pushed into position with the top layers being simply laid into position on top of the oven chamber. In a kitchen oven, the top layer also prevents heat from the oven from escaping through the burners on top of the range. It is common for a less-expensive oven to contain less oven insulation than a more expensive model.