What is one common feature of a multi-fuel burner?

A multi-fuel burner is designed to provide flexibility in fuel selection, which is its defining characteristic. The ability to use different types of liquid or gas fuels allows for adaptability in various applications and situations. This feature is particularly advantageous in settings where fuel availability might vary or where it is necessary to switch between fuels for economic or safety reasons.

In contrast, the other options highlight features that do not apply to multi-fuel burners. For example, burning solid fuels exclusively pertains only to a specific type of burner, while automatic switching to a backup power source and built-in air conditioning capabilities are not inherent to the function of a multi-fuel burner. Instead, these features align more closely with other equipment or systems outside the scope of a multi-fuel burner’s primary purpose.