What counts as a passed coil?

Count a coil only when its recorded result satisfies the leak and drain checks included in your chosen procedure. Apply that same definition to the tested population.

Can I combine separate leak and drain totals?

No. This model needs one paired outcome for each tested coil. Separate totals cannot show how many coils cleared both checks.

How do I compare initial tests with rechecks?

Calculate initial acceptance and post-rework acceptance separately. Recount each coil once within each selected population, and label the reporting basis so improvements are traceable.

Why can the shortfall be negative?

A negative value means the recorded pass percentage exceeds your target. For 243 accepted coils out of 250 against 97%, the shortfall is −0.2 percentage points.

HVAC Ductwork, Air Handling & Mechanical Products calculator

Coil Leak and Drain Pass Rate Calculator

Measure the share of coils passing the leak and drain procedure. Enter passed and tested counts plus the reporting target.

What this calculator does

Measure the share of coils passing the leak and drain procedure.

Formula used

Acceptance % = Accepted items × 100 ÷ Tested items
Not accepted = Tested items − Accepted items
Target shortfall = Target % − Acceptance %

Inputs explained

Passed Coil Tests: Accepted items from the completed inspection record.
Tested Coils: All items assessed under the same acceptance procedure.
Acceptance Target: Required acceptance percentage for this reporting period.

How to use the result

Best suited to inspection trend reviews, acceptance target checks.
This does not set a test pressure, leakage class or acceptance specification.

Current U.S. benchmarks

Industrial electricity averages 9.77 cents per kWh across the U.S. (EIA, Jul 2026), up 4.7% from a year earlier. Energy-intensive steps carry this directly into unit cost.
U.S. housing starts run at 1,275k per year (Census, Aug 2026), down 1.2% from a year earlier, the demand driver for building products.

Common questions

What counts as a passed coil? Count a coil only when its recorded result satisfies the leak and drain checks included in your chosen procedure. Apply that same definition to the tested population.
Can I combine separate leak and drain totals? No. This model needs one paired outcome for each tested coil. Separate totals cannot show how many coils cleared both checks.
How do I compare initial tests with rechecks? Calculate initial acceptance and post-rework acceptance separately. Recount each coil once within each selected population, and label the reporting basis so improvements are traceable.
Why can the shortfall be negative? A negative value means the recorded pass percentage exceeds your target. For 243 accepted coils out of 250 against 97%, the shortfall is −0.2 percentage points.

Last reviewed 2026-10-12.