Boilers and burners require a combustion analysis on a regular basis for proper operation. The combustion analyzer measures the air-to-fuel ratio of the burner and calculates the efficiency of the boiler. The analyzer also may display the emissions output from the boiler. Each cubic foot of natural gas burned produces:
Imagine we have a 100%-efficient boiler and to achieve that efficiency, our burner requires 10 parts of air to 1 part of gas. It is not realistic or safe to operate at that efficiency, so we increase the supply from 10 to 12 parts of air and now have 20% extra or “excess air.” Our burner efficiency is sacrificed but we have a system that heats without continuous monitoring (see Figure 1).