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.
- 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
- 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.
Building Energy Codes Program -
Code Note - Residential Fan Efficiency