Plant Utilities worked example

Chiller Load at 12% startup and fouling allowance: a worked example

This scenario runs the chiller load calculation on the strong side: 12% startup and fouling allowance, with every other input held at its documented default. Use it when reviewing chiller load for a utility budget, maintenance priority, capacity check, energy project, or production support plan.

The inputs for this scenario

  • Required chilled-water load duty: 360 chiller-min (unchanged)
  • Chiller cooling-rate coverage: 1 chiller-min / min (unchanged)
  • Startup and fouling allowance: 12 % (raised for this scenario; the documented default is 10)

Working through the calculation

  • Applying the documented formula (Base chiller load time = required chilled water load time รท chiller load coverage rate) to the inputs above produces each figure below.
  • At this operating point the engine returns 403 min for required chiller load time, the number this scenario is built around.
  • At this operating point the engine returns 360 min for base chiller load time.
  • At this operating point the engine returns 12 % for allowance applied.
  • At this operating point the engine returns 1 chiller-min / min for utility coverage rate.

How this compares with the baseline

  • Against the tool's baseline example, where startup and fouling allowance sits at 10% and the headline result is 396 min, this scenario comes in 1.82% above the baseline at 403 min.
  • Use it when scheduling chiller run time for a cooling window or estimating operating hours for a known chilled-water duty. 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

  • Required chiller load time: 403 min (headline result)
  • Base chiller load time: 360 min
  • Allowance applied: 12 %
  • Utility coverage rate: 1 chiller-min / min

Run it with your numbers

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

Last reviewed 2026-05-12.