If the bathroom fan is part of the whole-house mechanical ventilation system (WHMV), there are code provisions that should be verified during plan review and field inspection depending upon codes enforced in your jurisdiction.
Plan Review
- Review fan specifications meet cfm and cfm/W (efficacy/energy efficiency)
2012 IECC, Table 403.5.1
| Fan Location | Airflow Rate Minimum (cfm) | Minimum Efficacy (cfm/W) | Airflow Rate Maximum (cfm) |
|---|---|---|---|
| Bathroom, utility room | 10 | 1.4 | < 90 |
| Bathroom, utility room | 90 | 2.8 | Any |
- Verify all fans that are part of the WHMV meet efficacy requirements
Field Inspection
- Confirm fan(s) meet the approved efficacy (matches what was plan reviewed)
Note: the cfm/W might not be shown on the fan (label), refer to technical specifications.
Technical Validation(s)
Building Energy Codes Program -
Code Note - Residential Fan Efficiency
http://www.energycodes.gov/sites/default/files/documents/cn_residential_fan_efficiency.pdf