What happens to the combustion process when there is insufficient air?

When there is insufficient air during the combustion process, the fire cannot sustain itself and will eventually extinguish. Combustion is a chemical reaction that requires three key components: fuel, heat, and an oxidizer, typically oxygen from the air. When there is a lack of available oxygen, the reaction cannot continue at the required rate, which leads to incomplete combustion. This insufficient supply of air means that the fuel is not fully consumed and the heat generated is not enough to maintain the fire, causing it to go out.

In terms of what happens with insufficient air, the fire does not burn hotter since a limited oxygen supply restricts the efficiency of combustion, leading to cooler flames and smoke production due to unburned fuel. Similarly, without adequate air, the fire cannot spread as rapidly because burning relies on access to fresh air to generate heat and facilitate further combustion. Spontaneous ignition is also unlikely in these circumstances as it requires specific conditions and enough heat to ignite fuel without an external ignition source. Therefore, the most accurate outcome of insufficient air in a combustion scenario is that the fire goes out.