Plant Utilities worked example

Boiler Efficiency Gap at 97% target boiler efficiency: a worked example

This scenario runs the boiler efficiency gap calculation on the strong side: 97% target boiler efficiency, with every other input held at its documented default. Use it when reviewing boiler efficiency gap for a utility budget, maintenance priority, capacity check, energy project, or production support plan.

The inputs for this scenario

  • Target boiler efficiency: 97 % (raised for this scenario; the documented default is 84)
  • Measured boiler efficiency: 78 % (unchanged)
  • Reference boiler efficiency: 84 % (unchanged)

Working through the calculation

  • Applying the documented formula (Efficiency gap = target boiler efficiency - measured boiler efficiency) to the inputs above produces each figure below.
  • At this operating point the engine returns 22.62 % for margin, the number this scenario is built around.
  • At this operating point the engine returns 19 value for absolute margin.
  • At this operating point the engine returns 97 value for available amount.
  • At this operating point the engine returns 78 value for required amount.

How this compares with the baseline

  • Against the tool's baseline example, where target boiler efficiency sits at 84% and the headline result is 7.14 %, this scenario comes in 217% above the baseline at 22.62 %.
  • Use it right after a flue-gas analysis, seasonal combustion tune, or when comparing a boiler's current stack loss against its nameplate or ASME PTC 4 design efficiency. Treat this as a target state: the delta against the baseline quantifies what the improvement is worth before you commit to chasing it.

Results at a glance

  • Margin: 22.62 % (headline result)
  • Absolute margin: 19 value
  • Available amount: 97 value
  • Required amount: 78 value

Run it with your numbers

  • Every input above is editable in the live Boiler Efficiency Gap calculator, which recalculates instantly and can be shared with the inputs intact.

Last reviewed 2026-05-12.