Air Balance Calculator

Calculate supply, return, outdoor air, and exhaust quantities for proper building pressurization.

Supply Air

Return Air

Exhaust Air

Building Data

Air Balance Guidelines

Building TypePressurization
Office/Commercial+0.03" to +0.05"
Hospital (general)+0.01" to +0.03"
Clean Room+0.05" to +0.10"
Laboratory (negative)-0.03" to -0.05"
Kitchen-0.02" to -0.05"

Balance Equation

Supply = Return + Exhaust + Building Exfiltration

Outdoor Air = Exhaust + Pressurization Air

For positive pressure: Supply > (Return + Exhaust)