Formula & worked example
ΔPsystem=ΣΔPcomponents; margin=ΔPfan−ΔPsystem.
A 750 Pa fan against 180 Pa duct, 120 Pa fittings, 150 Pa filter, 170 Pa coil and 60 Pa terminals leaves 70 Pa margin.
HVAC engineering calculator · Updated Sep 17, 2026
HVAC Air-Side Pressure Budget Calculator — ESP, Components & Fan Margin
Sum duct, fitting, filter, coil, grille and accessory pressure losses, compare them with available fan static pressure and report remaining margin.
Inputs
Live result
Total design pressure loss 680 Pa
Fan available static 750 Pa
Remaining margin 70 Pa
Static budget used 90.666667%
Fan static covers entered losses
Assumptions & limits
- Component losses are entered at the design airflow.
- A full network may require branch-by-branch critical-path analysis.
Frequently asked questions
What does this HVAC Air-Side Pressure Budget Calculator calculate?
Sum duct, fitting, filter, coil, grille and accessory pressure losses, compare them with available fan static pressure and report remaining margin.
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.