AC Coil Delta-T Checker
Evaporator temperature split — the 60-second airflow & charge health check.
High ΔT almost always means airflow, not refrigerant — check the filter before the gauges. Humidity shifts the target: muggy days legitimately read 2–3 °C lower.
Formula
AC Coil Delta-T Checker is a free delta t check for HVAC designers, technicians and energy auditors — instant, accurate and 100% client-side, with the governing formula and reference shown next to the result so the number can be defended, not just quoted.
About AC Coil Delta-T Checker
Evaporator temperature split — the 60-second airflow & charge health check. The calculation implements ΔT = T_return − T_supply (dry coil; humid climates trend lower) (ACCA technician diagnostics; manufacturer charging charts). High ΔT almost always means airflow, not refrigerant — check the filter before the gauges. Humidity shifts the target: muggy days legitimately read 2–3 °C lower.
How to use AC Coil Delta-T Checker
- 1Enter Return air temperature in °C.
- 2Enter Supply air temperature in °C.
- 3Read Temperature split instantly — no submit button needed.
Why use AC Coil Delta-T Checker?
- ✓Implements the standard formula — ΔT = T_return − T_supply (dry coil; humid climates trend lower)
- ✓Reference cited on-page: ACCA technician diagnostics; manufacturer charging charts
- ✓Built-in engineering verdict flags out-of-range results instantly
- ✓Runs entirely in your browser — nothing uploaded, free forever
Frequently asked questions
What formula does the AC Coil Delta-T Checker use?+
It computes ΔT = T_return − T_supply (dry coil; humid climates trend lower), per ACCA technician diagnostics; manufacturer charging charts. The formula is displayed under the result.
What should I keep in mind when using this calculator?+
High ΔT almost always means airflow, not refrigerant — check the filter before the gauges. Humidity shifts the target: muggy days legitimately read 2–3 °C lower.
Is this based on ASHRAE methods?+
The calculations follow the standard ASHRAE/ISHRAE formulations cited under the result, simplified where industry practice does the same. For permit-grade design, confirm with the full code procedure.
Is the AC Coil Delta-T Checker free to use?+
Yes — completely free, no sign-up, no limits. It runs client-side in your browser, so inputs stay private and results are instant even on slow connections.
Related Engineering tools
Reynolds Number Calculator
Compute Re from density, velocity, pipe diameter and viscosity — with instant laminar/turbulent classification.
● LiveLaminar vs Turbulent Flow Classifier
Classify hydraulic-oil or process-fluid flow regime from kinematic viscosity, line velocity and tube bore.
● LiveBernoulli Equation Solver
Solve downstream pressure between two points from velocities, elevations and fluid density (ideal, lossless).
● Live