Process Manufacturing worked example

Heat-Up Time at 21% heat-loss and hold-up allowance: a worked example

This scenario runs the heat-up time calculation on the strong side: 21% heat-loss and hold-up allowance, with every other input held at its documented default. estimating the heating window for a batch, wash solution, or process fluid

The inputs for this scenario

  • Total heat load required to reach setpoint: 850,000 Btu (unchanged)
  • Effective heater output at operating conditions: 18,000 Btu / min (unchanged)
  • Heat-loss and hold-up allowance: 21 % (raised for this scenario; the documented default is 18)

Working through the calculation

  • Applying the documented formula (Base heat-up time = required heat load รท actual heating rate) to the inputs above produces each figure below.
  • At this operating point the engine returns 57.14 min for required heat-up time, the number this scenario is built around.
  • At this operating point the engine returns 47.22 min for base heat-up time.
  • At this operating point the engine returns 21 % for heat-up allowance applied.
  • At this operating point the engine returns 18,000 pieces / min for actual heating rate.

How this compares with the baseline

  • Against the tool's baseline example, where heat-loss and hold-up allowance sits at 18% and the headline result is 55.72 min, this scenario comes in 2.54% above the baseline at 57.14 min.
  • Use it during batch scheduling, heater sizing, or when quoting cycle time for a new product on existing equipment. 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 heat-up time: 57.14 min (headline result)
  • base heat-up time: 47.22 min
  • heat-up allowance applied: 21 %
  • actual heating rate: 18,000 pieces / min

Run it with your numbers

  • Every input above is editable in the live Heat-Up Time calculator, which recalculates instantly and can be shared with the inputs intact.

Last reviewed 2026-05-12.