Building Infiltration Calculator
Calculate air infiltration rates and thermal loads from building air leakage.
ACH Guidelines
| Construction | Natural ACH | ACH50 |
|---|---|---|
| Passive House | 0.05 | <0.6 |
| Energy Star | 0.15-0.25 | <5 |
| Code Minimum | 0.30-0.35 | <7 |
| Older Homes | 0.50-1.0 | 10-20 |
Formulas
ACH to CFM: CFM = ACH x Volume / 60
Sensible: Qs = 1.08 x CFM x DT
Natural ACH: ACH50 / N-factor (15-20)