Mixed Air Calculator

Calculate mixed air conditions for HVAC systems and ventilation design

Outdoor Air Conditions

°F

Return Air Conditions

°F
Percentage of outdoor air in the mixture

Understanding Mixed Air Calculations

Key Components

1. Air Properties

  • Dry bulb temperature
  • Relative humidity
  • Humidity ratio
  • Enthalpy

2. System Parameters

  • Air flow rates
  • Mixing ratios
  • System efficiency
  • Energy recovery

Common Applications

Application Typical OA% Considerations
Office Buildings 15-25% Occupancy levels, energy efficiency
Schools 20-30% High occupancy, CO2 levels
Hospitals 25-100% Infection control, pressure relationships
Industrial 10-100% Process requirements, contamination control

Design Tips

Important considerations for mixed air systems:

  • Monitor psychrometric conditions
  • Consider seasonal variations
  • Evaluate energy recovery options
  • Maintain proper ventilation rates
  • Check for condensation risks