Heat Exchanger, Coil & Radiator Manufacturing worked example

Brazing Furnace Load at 99% furnace availability and uptime: a worked example

What does the result look like when furnace availability and uptime reaches 99%? The full calculation is worked below with real intermediate numbers. Use it when a controlled atmosphere brazing furnace, vacuum brazing furnace, or batch braze oven is the constraint for radiator, charge air cooler, condenser, or evaporator production.

The inputs for this scenario

  • Cores loaded per furnace cycle: 4 cores / cycle (unchanged)
  • Usable furnace cycles per shift: 24 cycles / shift (unchanged)
  • Furnace availability/uptime: 99 % (raised for this scenario; the documented default is 90)
  • Post-braze first-pass yield: 97 % (unchanged)

Working through the calculation

  • Applying the documented formula (Gross brazed core capacity = cores loaded per cycle × usable furnace cycles) to the inputs above produces each figure below.
  • At this operating point the engine returns 92.19 cores / shift for good brazed core output, the number this scenario is built around.
  • At this operating point the engine returns 96 cores / shift for gross furnace output.
  • At this operating point the engine returns 0.96 cores / shift for furnace downtime loss.
  • At this operating point the engine returns 2.85 cores / shift for post-braze reject loss.

How this compares with the baseline

  • Against the tool's baseline example, where furnace availability and uptime sits at 90% and the headline result is 83.81 cores / shift, this scenario comes in 10% above the baseline at 92.19 cores / shift.
  • A figure at this level is achievable when furnace availability and uptime is genuinely sustained, not just peaked for a shift. It models a single furnace at steady state and uses average uptime and yield — it does not capture cycle-time variation, load-mix changes or rework that is later recovered.

Results at a glance

  • Good brazed core output: 92.19 cores / shift (headline result)
  • Gross furnace output: 96 cores / shift
  • Furnace downtime loss: 0.96 cores / shift
  • Post-braze reject loss: 2.85 cores / shift

Run it with your numbers

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

Last reviewed 2026-05-12.