Which type of oil burner operates without external air pressure?

An atmospheric burner is designed to operate without the need for external air pressure to atomize the fuel. This type of burner relies on the natural draft created by the hot gases rising through the combustion chamber to draw in the necessary air for combustion. The mixing of air and fuel occurs primarily due to the natural atmospheric pressure, which allows for a simpler and more straightforward design.

In contrast, mechanical burners use fans or blowers to assist in mixing air and fuel, while centrifugal and pressure atomizing burners rely on external pressure mechanisms to assist with atomization and air/fuel mixing. This characteristic of atmospheric burners makes them suitable for applications where a simple design and lower operational complexity are desired. Their reliance on ambient conditions instead of external pressurization for functioning is the primary reason why they serve specific operational contexts effectively.