Airflow Calculator
Quick estimation of system airflow for HVAC performance evaluation
Note: This calculator provides quick estimates using simplified assumptions. For precise analysis, verify measurements with professional tools such as manometers or anemometers. Particularly useful for evaluating aging R-22 systems where airflow issues are common.System Parameters
Typical range: 0.3 - 0.8 inches WC
Optional - for velocity calc
Optional - for comparison
Airflow Analysis
Enter system parameters and click "Calculate Airflow" to see analysis
Airflow Guidelines & Formula
Standard CFM per Ton:
- Optimal: 400 CFM/ton
- Acceptable: 350-450 CFM/ton
- Minimum: 300 CFM/ton
- High: 450+ CFM/ton
Calculation Formula:
- CFM = BTU/hr ÷ (1.08 × ΔT)
- ΔT = Return Air - Supply Air
- 1.08 = Standard air factor
- Typical ΔT: 18-22°F (cooling)
Common R-22 Issues:
- Dirty evaporator coils
- Clogged air filters
- Aging ductwork leaks
- Blower motor degradation