Formula & worked example
BF=(Tleave−Tadp)/(Tenter−Tadp); CF=1−BF.
Air entering at 27°C, leaving at 14°C with 10°C ADP gives BF≈0.235 and contact factor≈0.765.
HVAC engineering calculator · Updated Sep 17, 2026
Cooling Coil Bypass Factor Calculator — BF, Contact Factor & ADP
Calculate cooling-coil bypass factor from entering, leaving and apparatus-dew-point temperatures, plus contact factor and reverse leaving-air temperature.
Inputs
Live result
Bypass factor 0.23529412
Contact factor 0.76470588
Contact effectiveness 76.470588%
Assumptions & limits
- Dry-bulb straight-line coil model is used.
- ADP is an effective saturated-coil surface state; verify against coil selection data.
Frequently asked questions
What does this Cooling Coil Bypass Factor Calculator calculate?
Calculate cooling-coil bypass factor from entering, leaving and apparatus-dew-point temperatures, plus contact factor and reverse leaving-air temperature.
Is this suitable for final equipment selection?
Use it as an auditable engineering cross-check. Final selections should use measured design conditions, manufacturer data, applicable standards and local code.
Why does MAXScanner expose the assumptions?
HVAC shortcuts can hide density, pressure, concentration and effectiveness assumptions. Exposing them makes the result easier to verify and revise.