How do Ovens Cook Food
There are two main varieties of household oven – gas and electric – with a few hybrids between the two.
The former work by burning gas to warm a heating element and/or a metal cooking compartment directly. The gas supply is ignited using an electric lighter that proceeds through one or more burner units to warm the air in the oven compartment(s) to the temperature designated by the thermostat.
Within the category of gas ovens there are two major types: those that use heating elements – strips of metal in the top and bottom of the oven, and those that heat a metal cooking compartment directly. In both cases, the oven works by emitting thermal radiation, either baking (heated from below) or broiling (heated from above) the food. As a general rule, compartments utilize indirect heat, while elements point heat in a specific direction.
Electric ovens also come in two main flavours: standard thermal radiation and convection. Thermal electric ovens work on the same principle as their gas counterparts, with metal elements. Here the energy source is electricity, which passes as a current through the inner, coiled wires of the elements.
Convection ovens are of similar construction to standard thermal radiation cookers but introduce an air-circulating fan into the mix. This fan, which is installed in the rear wall of the oven cavity, aims to distribute the directed radiation from the heating elements around the oven, thereby delivering a more even spread of heat and a faster, more balanced cooking environment as a result.
Inside a Rayburn gas oven
Insulated lids – When the hotplate is not in use, two large lids can be closed to retain its heat. The lids have an insulated, polished surface allowing them to be handled without oven gloves.
Burner unit – The Rayburn’s heat source, the burner unit allows a continuous gas burn or, on advanced models, a high-power on/off operation. Heat from the burner warms both the compartments and the hotplate.
Main oven – The principal oven compartment is made from cast iron and uses indirect heat from the burner to cook foods evenly and efficiently. A thermodial embedded in the oven door measures the interior temperature.
Lower oven – A secondary oven compartment operates at half the temperature of the main oven. Also made from cast iron, this section enables cooked items to be kept warm or for certain food to be slow-cooked.