Ventilation Systems Inspection

Exhaust fans required in all bathrooms and recommended in kitchens and laundry rooms. Must duct to exterior, never into attic or crawl space.

1. Test bathroom fans — hold tissue at grille, should be drawn in

2. Verify each fan ducts to exterior — go outside and verify air exits

3. Check kitchen range hood — verify exterior exhaust (not recirculating)

4. Verify dryer vents to exterior through metal duct

5. Check that fans are sized appropriately (1 CFM per sq ft of bathroom)

6. Test fan noise level — should not be excessively loud

7. Verify fans have timers or humidity sensors (better moisture control)

8. Check duct insulation in unconditioned spaces (prevents condensation)

- Fans ducted into attic (moisture causes mold and rot in roof structure)

- Fans ducted into crawl space (moisture damage)

- Undersized fans (don't remove moisture effectively)

- No fan in bathrooms (code requirement)

- Duct not insulated (condensation drips back)

- Fan without timer (occupants forget to run it long enough)