What is essential for the ignition of fuel in a furnace?

The ignition of fuel in a furnace primarily requires a high enough temperature to initiate the combustion process. When fuel is heated to its ignition point, it begins to vaporize and react with oxygen in the air, leading to combustion. This temperature threshold varies depending on the type of fuel used.

While other factors, such as fuel type, air-to-fuel ratio, and pressure, can influence combustion efficiency and characteristics, none are as critical as achieving the necessary temperature for ignition. Without reaching this critical temperature, even a well-mixed air-fuel ratio or the appropriate fuel type will not result in combustion. Therefore, the importance of temperature in the ignition process makes it the essential factor for fuel ignition in a furnace.