Which of the following factors does NOT determine the performance of a fuel oil burner?

The performance of a fuel oil burner is influenced by several key factors, among which are oil viscosity, air delivery capacity, and burner design. Oil viscosity is crucial because it affects how easily the fuel oil can be atomized and burned. Higher viscosity oils require more energy to pump and atomize, impacting combustion efficiency and overall performance. Similarly, air delivery capacity is vital as it ensures that the right amount of oxygen mixes with the oil for optimal combustion. Insufficient air delivery can lead to incomplete combustion, resulting in lower efficiency and potential buildup of harmful byproducts.

Burner design also plays a critical role, as it dictates how effectively the burner can atomize the fuel and mix it with air, influencing both efficiency and emissions. Each of these factors directly affects how well the burner operates.

In contrast, air temperature, while it can influence combustion characteristics to some degree, does not have as direct an impact on the fundamental performance of the burner itself compared to the other factors listed. Consequently, it is the factor that does not significantly determine how well the burner performs in comparison to oil viscosity, air delivery capacity, and burner design.