What is the system load of an industrial boiler?

System load is measured in either BTUs or tons of steam (at a specific pressure and temperature). It would be nearly impossible to size and select a boiler(s) without knowing the system load requirements. Knowing the requirements leads to the following information:

The boiler(s) capacity, taken from the maximum system load requirement.

The boiler(s) turndown, taken from the minimum system load requirement.

Conditions for maximum efficiency, taken from the average system load requirement.

Determining the total system load requires an understanding of the type(s) of load in the system. There are three types of loads: heating, process, and combination.