Mixed Air Temperature Calculator

Find the temperature of two blended air streams.

Airflow 1 (CFM)

Temperature 1 (°F)

Airflow 2 (CFM)

Temperature 2 (°F)

Mixed temperature (°F) 66.25

Formula: T = (Q₁T₁ + Q₂T₂) ÷ (Q₁ + Q₂)

Step-by-step with your numbers:

1. Values used:

2. Airflow 1 = 300 CFM

3. Temperature 1 = 75 °F

4. Airflow 2 = 100 CFM

5. Temperature 2 = 40 °F

7. Mixed temperature = 66.25°F

Did we solve your problem today?

Mixing two air streams gives a flow-weighted average temperature — common in ventilation.

The math behind it

T_mix = (Q₁T₁ + Q₂T₂) ÷ (Q₁ + Q₂), weighting each stream by its airflow.

300 CFM at 75 °F + 100 CFM at 40 °F → 66.25 °F.

Does humidity affect this?

Slightly; for precise work use enthalpy mixing on a psychrometric chart.