An infrared flame screen is the cleanest, most efficient way to produce energy out of any type of fuel. Ultra low NOx specs fulfill the strictest pollution standards. It may not mean much at this point, but it is all about your health as the operator: your surroundings and your coffee. No soot accumulation in the drum to coat your coffee, none of the harmful CO produced during operation, no irritated red eyes at the end of the day. Burner runs the full gamut, at any stage, from low power to overkill, controlled by your choice.