Mixed Air Calculator — HVAC Mixing Conditions | PsychroCalcLab

Calculate mixed air conditions from two air streams. Determine the mixed temperature, humidity ratio, and enthalpy for HVAC systems.

How to Use

  1. Enter conditions and mass flow rates for both air streams.
  2. The results update automatically as you change the input values.
  3. Review the calculated value and the engineering notes shown below the result.

Frequently Asked Questions

What is mixed air in HVAC?

Mixed air is the combination of return air from the building and outside fresh air, mixed in the air handling unit before being conditioned.

How is the mixed air temperature calculated?

It is calculated using the mass flow rates and temperatures of the two individual air streams. Our calculator performs this mass balance equation automatically.

Why is calculating mixed air important?

Knowing the mixed air conditions is essential to determine the actual cooling or heating load the HVAC coil must handle.

Can I use this for economizer sizing?

Yes, by calculating the mixed air temperature and enthalpy under various outside air fractions, you can determine the optimal economizer setpoints and maximize free cooling efficiency in your building.