KPIs & Targets

Heat Exchanger, Coil, and Radiator Manufacturing KPIs and Benchmarks

World-class versus typical target numbers for the KPIs that decide coil-line output, and where to pull each lever.

Post-braze first-pass yield is the KPI that governs a coil line, because a reject here scraps a fully valued core. World-class controlled-atmosphere and vacuum aluminum brazing lines sustain 97 to 99 percent first-pass; typical lines run 93 to 96 percent, and anything below 92 percent signals a fluxing, fixture, or atmosphere control problem worth a containment review. Measure it at the leak booth as passed cores divided by brazed cores, excluding rework from the numerator so the number stays honest. The levers are atmosphere dew point and oxygen control, fixture flatness, and flux application consistency, not test-station tuning.

Leak-test first-pass yield sits just downstream and should track 95 to 99 percent on mature brazed copper and aluminum lines. Do not conflate it with braze yield: the leak booth measures the same defects the braze process created, so a leak-test yield stuck in the low 90s is usually a braze or expansion-tooling issue upstream, not a booth problem. Track it per product family, because thin-wall and multi-pass cores leak more. Improvement comes from stabilizing the joint upstream and from tightening evacuation and dwell so borderline leakers are caught first-pass rather than escaping to field returns.

Furnace availability is the highest-leverage throughput KPI on the line. The braze furnace is the most expensive and least flexible asset, so target 92 percent or better uptime; typical lines sit at 85 to 90 percent, and each lost point removes about one good core per shift on a 96-core gross furnace. Measure it as brazing time divided by scheduled time from the furnace log, not an optimistic target. Levers are changeover reduction, atmosphere-upset prevention, and preventive maintenance on belt or conveyor drives. Recovering uptime from 90 to 95 percent adds roughly 4 to 5 cores per shift with zero capital.

Overall equipment effectiveness on the constraint, usually the leak booth, ties availability, performance, and quality together. World-class OEE on a coil cell runs 80 to 85 percent; typical is 55 to 65 percent, and the gap is almost always availability and minor stoppages rather than slow cycles. Compute it as the product of the three factors on the bottleneck station only, so you improve what actually caps output. If good leak-tested output is 168 against a 192 gross, that 12.5 percent loss is your OEE headroom. Attack changeover and short stops first; they usually beat chasing the last point of yield.

Scrap rate and yield tiers deserve a KPI of their own because they compound. Target under 3 percent tube scrap on straight-cut work and under 6 percent on hairpin-bent cores; combined with braze and leak losses, rolled throughput yield should clear 90 percent on a healthy line. Rolled yield of 0.97 bend x 0.97 braze x 0.98 leak is 92.2 percent, meaning nearly 8 percent of started material never ships. Measure each tier separately so you know where value is lost. The levers are bend-tooling condition, mandrel wear, and stabilizing the braze that drives most leak rejects.

Takt attainment measures whether the line hits its required pace. Target 90 percent or better attainment against a takt set by build volume and staffed time; typical lines drift to 75 to 85 percent as changeover and imbalance eat the schedule. Measure it as cores completed divided by cores the takt demanded across the shift. A cell at 5.0 minute takt that averages 5.7 minutes is running 88 percent of pace and will miss the daily commitment by roughly 11 cores on a 90-core plan. The lever is rebalancing the slowest station, usually the braze load or leak booth, toward the takt clock.

Refrigerant charge accuracy and scrap cost per core round out the money-adjacent KPIs. Target charge accuracy within plus or minus 2 percent of the calculated volume, because both undercharge and overcharge generate field failures that dwarf the material saving. Track scrap cost per good core as a rolling dollar figure, not just a percentage, so a shift of value-heavy post-braze rejects shows up even when the piece-count scrap rate looks flat. A world-class line holds scrap cost under 4 percent of build cost; typical lines run 6 to 9 percent, most of it concentrated in fully valued cores lost after brazing.

To improve, sequence the levers by leverage, not by ease. Furnace uptime and braze first-pass yield move the most shippable cores per shift, so fix atmosphere control and changeover first. Next, stabilize the joint to lift leak-test yield and cut field returns. Then rebalance to takt so the constraint station stops gating the cell. Use Brazing Furnace Load and Leak Test Capacity to quantify the good-core gain from each point of uptime or yield before committing effort, and re-baseline monthly. A coil line holding 92 percent-plus braze yield, 92 percent-plus furnace uptime, and 90 percent-plus takt attainment is in world-class territory.

Published 2026-07-01.